BOREAS AFM-05 Level-1 Upper-Air Network Data Summary The BOREAS AFM-05 team collected and processed data from the numerous radiosonde flights during the project. The goals of the AFM-05 team were to provide large scale definition of the atmosphere by supplementing the existing AES aerological network, both temporally and spatially. This data set includes basic upper-air parameters collected from the network of upper-air stations during the 1993, 1994, and 1996 field campaigns over the entire study region. The data are contained in tabular ASCII files. Table of Contents * 1 Data Set Overview * 2 Investigator(s) * 3 Theory of Measurements * 4 Equipment * 5 Data Acquisition Methods * 6 Observations * 7 Data Description * 8 Data Organization * 9 Data Manipulations * 10 Errors * 11 Notes * 12 Application of the Data Set * 13 Future Modifications and Plans * 14 Software * 15 Data Access * 16 Output Products and Availability * 17 References * 18 Glossary of Terms * 19 List of Acronyms * 20 Document Information 1. Data Set Overview 1.1 Data Set Identification BOREAS AFM-05 Level-1 Upper-Air Network Data 1.2 Data Set Introduction The BOReal Ecosystem-Atmosphere Study (BOREAS) Aircraft Flux and Meteorology Team 5 (AFM-05) oversaw the launch of radiosonde balloons during each Intensive Field Campaign (IFC) in 1993, 1994, and 1996. These launches helped to provide a better understanding of the atmosphere during the data measurement periods. 1.3 Objective/Purpose The goals of AFM-05 were to provide large-scale definition of the atmosphere by supplementing the existing Atmospheric Environment Service (AES) aerological network, both temporally and spatially; provide a large and fine enough mesh to satisfy the spatial requirements of mesoscale modelers; and provide appropriate temporal frequency to resolve diurnally varying atmospheric processes. 1.4 Summary of Parameters The data include parameters of location, date, time, geopotential height, atmospheric pressure, temperature, dew point temperature, wind direction and speed, u and v components of the wind, potential temperature and equivalent potential temperature, mixing ratio, relative humidity (RH), radiosonde range, radiosonde azimuth angle, radiosonde elevation, and the type of field measured. 1.5 Discussion The BOREAS upper-air data network operated during the 1993, 1994, and 1996 IFCs. Three proximate sites in the existing AES network (at Saskatoon, SK; The Pas, MB; and Churchill, MB) and two military stations (at Primrose Lake, AB, and Shilo, MB) contributed soundings, augmenting their routine 1200 and 0000 Universal Time Code (UTC) soundings with an additional 1800 (UTC) sounding. A separate National Aeronautics and Space Administration (NASA) activity made a limited number of 1200 UTC soundings at Lynn Lake, MB, during the 1994 IFC-2. BOREAS augmented the existing network in 1994 with three additional sites at Candle Lake, SK; Key Lake, SK; and Thompson, MB. Soundings were made routinely at 1200, 1800, and 0000 (UTC) as well as at 1400, 1600, 2000, and 2200 (UTC) on fair-weather days in IFCs 1, 2, and 3 at Candle Lake and Thompson. The Shilo data (collected in 1994) are not included in the BOREAS Information System (BORIS) data set because of their very coarse resolution and Shilo's distance from the area. In 1996, routine soundings were performed at 1200 and 0000 (UTC) daily at three existing upper-air sites near the BOREAS study areas (Saskatoon, The Pas, and Churchill). BOREAS augmented the existing network in 1996 with upper-air sites at Candle Lake and Thompson where soundings were typically performed at 1200, 1600, 1800, 2000, 2200, and 0000 (UTC) on fair-weather days and at 1200, 1800, and 0000 (UTC) on poor-weather days. 1.6 Related Data Sets BOREAS AFM-05 Level-2 Upper-Air Network Standard Pressure Level Data 2. Investigator(s) 2.1 Investigator(s) Name and Title Alan Barr Atmospheric Environment Service National Hydrology Research Centre Alan Betts Atmospheric Research 2.2 Title of Investigation Upper-Air Network (AFM-05) Boundary Layer Research For BOREAS (AFM-08) 2.3 Contact Information Contact 1 ----------- Alan Barr Atmospheric Environment Service National Hydrology Research Centre Saskatoon, SK (306) 975-4324 (306) 975-6516 (fax) alan.barr@ec.gc.ca Contact 2 ----------- Charmaine Hrynkiw Atmospheric Environment Service National Hydrology Research Centre Saskatoon, SK (306) 975-5793 (306) 975-6516 (fax) hrynkiwc@nhrisv.nhrc.sk.ec.gc.ca Contact 3 ----------- Alan Betts Atmospheric Research Pittsford, VT (802) 483-2087 (802) 483-6167 (fax) akbetts@aol.com 3. Theory of Measurements Pressure, temperature, humidity, and wind measurements were converted from radiosonde signals received and processed by an upper-air receiver. Wind observations utilized radio-navigation. Wind speed and direction were determined by navigation networks (NAVAID) or via a radiotheodolite positioned near the release site. The NAVAID signals were relayed to the ground station for processing and wind vector computation. The radiotheodolite received signals from the radiosonde and recorded azimuth, elevation, and altitude, from which the trajectory of the radiosonde was calculated. Depending on the system, higher level processing was conducted after the pressure, temperature, humidity, and radiosonde position signals were converted (i.e., Vaisala). 4. Equipment 4.1 Sensor/Instrument Description Vaisala (Candle Lake, Key Lake, Thompson, and Churchill) Radiosonde Type: Vaisala RS80 Series VIZ W9000 (Saskatoon, Lynn Lake, The Pas - 1996) Radiosonde Type: VIZ-BEUKERS LO-CATE MICROSONDE Atmospheric Instrumentation Research, Inc. (A.I.R.) Radiosonde Type: A.I.R. Aerological Data REduction System (ADRES), The Pas - 1994 Radiosonde Type: 1680 MHz radiosonde Candle Lake Surface Observation Instruments ------------------------------------------- Temperature: mercury thermometer Humidity: wet bulb mercury thermometer Pressure: Druck digital Wind Direction and Speed: estimated Sling psychrometer (1996) Anemometer (1996) Aneroid barometer (1996) Thompson Surface Observation Instruments ---------------------------------------- Temperature: mercury thermometer Humidity: wet bulb mercury thermometer Pressure: Setra 270 Wind Direction and Speed: U2A Sling psychrometer (1996): used to measure surface temperature and humidity Anemometer (1996) Setra pressure transducer (1996) Key Lake and Churchill Surface Observation Instruments ------------------------------------------------------ Temperature: thermistor Humidity: lithium chloride dew cell Pressure: Setra Wind Direction and Speed: 78D The Pas Surface Observation Instruments --------------------------------------- Temperature: thermistor Humidity: lithium chloride dew cell Pressure: standard mercury barometer Wind Direction and Speed: U2A Saskatoon Surface Observation Instruments and Method ---------------------------------------------------- Temperature: mercury thermometer (sling psychrometer) Humidity: wet bulb mercury thermometer (sling psychrometer) Pressure: Ruska digital barometer Wind Direction and Speed: U2A Primrose Lake Surface Observation Instruments and Method -------------------------------------------------------- Temperature: mercury thermometer (ventilated Stevenson Screen) Humidity: wet bulb mercury thermometer (ventilated Stevenson Screen) Pressure: Ruska digital barometer Wind Direction and Speed: U2A 4.1.1 Collection Environment Upper-air data were collected in varying ambient weather conditions. 4.1.2 Source/Platform The platform for the data collection was weather balloons. 4.1.3 Source/Platform Mission Objectives The objective of the balloon was to carry the sonde up through the atmosphere. 4.1.4 Key Variables The primary quantities measured, both on the surface and in the upper atmosphere, were pressure, temperature, humidity, wind direction, and wind speed. 4.1.5 Principles of Operation The radiosondes used a small battery-powered transmitter that relayed messages to a receiver on the ground. As the radiosonde passed through the atmosphere, the sensors detected changes in pressure, temperature, and humidity. These changes were sent as signals to the receiver, which were then decoded as values of pressure, temperature, and humidity. An automatic tracking device determined the position of the radiosonde, which was translated into wind speed and direction by the receiver. A radiosonde consisted of the following major components: meteorological sensors that responded mechanically or electrically to changes in the parameters being measured (temperature, humidity, and pressure); a switching mechanism that connected the sensor outputs to the modulator circuitry; a modulator for regulating the carrier signal at a rate dependent on the electrical resistance of the temperature and humidity sensors; a transmitter for transmitting radio frequency signals back to the ground equipment; a power supply (battery) that produced the current required to operate the electronic circuitry; and a container or case made from polystyrene and cardboard used to house the electronic and mechanical components (this container was also designed to provide suitable exposure for the sensors). 4.1.6 Sensor/Instrument Measurement Geometry The measurements made by the sensor or calculated from the measurements varied in their geometric representation depending on the flight conditions. 4.1.7 Manufacturer of Sensor/Instrument Vaisala Radiosondes (Candle L., Churchill, Key L., Thompson): Vaisala, Inc. 100 Commerce Way Woburn, MA 01801 (617) 933-4500 (617) 933-8029 (fax) VIZ (Saskatoon, Lynn Lake, The Pas (1996)): VIZ Manufacturing Company 335 East Price Street Philadelphia, PA 19144-5782 (215) 844-2626 (215) 844-4410 (fax) A.I.R. (Primrose L.): Atmospheric Instrumentation Research, Inc. 8401 Baseline Road Boulder, CO 80303 (303) 499-1701 (303) 499-1767 (fax) 4.2 Calibration 4.2.1 Specifications Vaisala: Radiosondes were factory calibrated. The calibration tape accompanying each radiosonde was fed into the MW15 prior to launch. A calibration correction was applied to RH as described in Section 9.1. Vaisala (Candle Lake, Key Lake, Thompson and Churchill) Radiosonde Description: Type: Vaisala RS80 Series Description: Pressure Sensor: Capacitive aneroid; Resolution: 0.01 kPa; Precision: 0.05 kPa Humidity Sensor: Humicap thin film capacitor; Resolution: 1% RH; Precision: 2% RH; Lag: 1 s (for 6 m.s-1 flow at 100 kPa) Temperature Sensor: Capacitive bead; Resolution: 0.1 deg C; Precision: 0.2 deg C; Lag: < 2.5 s (for 6 m/sec flow at 100 kPa) Wind Direction and Speed: NAVAID (Loran-C or Omega) VIZ: Radiosondes were factory calibrated. VIZ W9000 (Saskatoon, Lynn Lake, The Pas - 1996) Radiosonde Description: Type: VIZ-BEUKERS LO-CATE MICROSONDE Pressure Sensor: Aneroid capsule (Ni-Span-C); Resolution: 0.01 kPa; Precision: 2 kPa Humidity Sensor: Carbon type, 10000; Resolution: 0.01% RH; Precision: 4% RH Temperature Sensor: Thermistor, rod type, 1400 ohms; Resolution: 0.01 deg C; Precision: 0.4 deg C Wind Direction and Speed: NAVAID (Loran-C or Omega) A.I.R.: Radiosondes were factory calibrated. Calibration coefficients were transmitted by the radiosonde. A.I.R. Radiosonde Description: Type: A.I.R. Intellesonde Description: Pressure Sensor: Aneroid pressure cell; Resolution: 0.01 kPa; Precision: 1 kPa Humidity Sensor: Carbon hygristor; Resolution: .01% RH; Precision: 3% RH Temperature Sensor: Thermistor; Resolution: 0.01 deg C; Precision: 0.5 deg C Wind Direction and Speed: Automatic Digital Radiotheodolite Each Intellisonde was factory calibrated with calibration coefficients stored in Read Only Memory (ROM). These coefficients were automatically transmitted to the receiver on power-up. ADRES, The Pas - 1994. Radiosonde Description: Temperature Sensor: Thermistor Wind Direction and Speed: Radiotheodolite 4.2.1.1 Tolerance Upper-Air Observations: Vaisala A radiosonde was accepted if: - Temperature reading was within +/- 2 degrees C of the manually observed temperature. - Pressure was within +/- 5 mb of the manually observed pressure. - Relative humidity was within +/- 20 percentage points of the manually observed relative humidity. Precision (Vaisala UAD Technical Manual): The following data were based on the twin ascent method. Two Vaisala series RS 80 radiosondes were suspended from one balloon and tracked by two independent receiving systems. The standard deviation of the differences was obtained after a number of ascents. Pressure measurement precision (1060 to 3 mb) is 0.05 mb. Temperature measurement precision was 0.2 degrees C and humidity was 3%. Wind vector measurement precision was 2 knots typical (Omega/Alpha) and 1 knot typical (Loran-C). VIZ A radiosonde was accepted if pressure was stable and was within 5 mb of the standard pressure measurement. A.I.R. The A.I.R. software compared the manually entered surface observation and alerted the user if a variable was far enough out of range to justify rejection of the radiosonde. Surface Observations: Not applicable. 4.2.2 Frequency of Calibration Upper-Air: Each radiosonde was checked against the surface observation before release. Surface Observations: Surface pressure sensors at Candle Lake, Saskatoon, and Thompson were checked against the AES regional standard pressure sensor prior to installation. Checks were performed at the beginning and end of the 1994 BOREAS field season. The surface pressure sensor at The Pas was checked once a year against the AES traveling standard pressure sensor, which in turn was checked against the AES regional standard. No checks were performed on the ordinary thermometers used at Candle Lake, Thompson Zoo, Saskatoon, and Key Lake. The dew cell sensors at Key Lake and Churchill were checked once a week in 1994. 4.2.3 Other Calibration Information None. 5. Data Acquisition Methods Vaisala Data Reception and Signal Processing Radiosonde (wind) tracking: NAVAID (Loran-C or Omega) Receiver: DigicoraII MW15 The Vaisala receiver (MW15) received and processed radiosonde signals in real time. The signals were converted to pressure, temperature, relative humidity, and wind and transferred to a PC. After all signals were converted to pressure, temperature, relative humidity, and wind speed and direction, proprietary higher level processing was conducted. Main Functions of the Main Processor Unit (p. 12, Vaisala UAD Technical Manual): 1) Error message handling and diagnostic analysis: Monitors operations by sending a message to the console upon detecting an error. Reads and analyzes error maps from other processor boards. If an error occurs, control is taken over by the error message handler. 2) Console command handling: Interprets commands given via console to application programs and to other processor boards. 3) Data handling and operational control: Transfers untreated, raw data from the receiver for processing, editing, and smoothing programs. Detects radiosonde launch and radiosonde burst. DATA EDITING (Appendix A, p. 1, Vaisala UAD Program Manual) Using established physical equations, the raw data (at 2-, 5-, or 10-second intervals) are edited to obtain the so-called filtered data. The purpose of data editing is to reject physically inconsistent data points. Editing is a nonlinear, nonrecursive method of data quality control. It is necessary because of the presence of telemetry noise, which tends to distort the determination of the signal frequency. Data editing is carried out in real time. There are four phases: 1) Coarse filtering 2) Fine filtering 3) Completion of the data set by interpolation 4) Data smoothing between turning points WIND EDITING (Appendix B, p. 1, Vaisala UAD Program Manual) The wind vector is computed based on the rate of change of the signal phase (phase derivatives), which is caused by the movement of the radiosonde. The rate of change of the phase depends on the movement of the radiosonde with respect to the transmitters and on the change in the distance between the radiosonde and the ground station. The basic solution is the so-called hyperbolic solution, where at least three signals are needed to locate the radiosonde and to compensate for drift of the local oscillator and the change in the distance between the radiosonde and the ground station. Computed wind vectors are passed through a quality control program to ensure that deviating vectors are rejected. Cubic spline fitting method is used to smooth the wind data after all stray points are rejected (according to Grubbs criterion). VIZ W9000 (Saskatoon, Lynn Lake, The Pas - 1996) A basic system consisted of the following: - Preamplifier/Antenna- Local NAVAID Antenna - A rack with a P90 bus interconnecting the backplane with the following: - 403-MHz Synthesized Receiver Module - System Interface Module - 403-MHz Antenna Control Module - Loran-C or Omega Amplifier Modules - NAVAID Tracker Module(s) - System computer, keyboard, hard drive, and two floppy drives - Color monitor - Printer Winds were determined by either Loran or Omega tracking. All available Loran chains or Omega stations were displayed to the user. The chains or stations were selected for the current tracker. A.I.R. Pressure was measured from 1050 to 5 mb by a capacitance type-pressure sensor. An internal temperature sensor located near the pressure sensor provided temperature compensation. Temperature was measured by a precision thermistor protected by a reflective coating intended to minimize radiation errors at high altitude. Relative humidity was measured by a carbon hygristor mounted on a double-shielded aerodynamic duct. The automatic ground station included an IBM-compatible computer with an A.I.R. data decoder board installed in a standard expansion slot. The computer was used to calculate pressure, temperature, humidity, and winds. The calculated parameters were then archived on the computer's hard disk. The A.I.R. system at Primrose Lake received 250-mW radiosonde transmissions, which were decoded and transferred to a PC, where unmodified pressure, temperature, and humidity data were saved. Wind data were automatically gathered using the A.I.R. Automatic Digital Radiotheodolite. This mechanism used a microprocessor-controlled planar phased array rather than a parabolic dish for tracking. The A.I.R. radiotheodolite electronically measured the small tracking error associated with the slew rate of the antenna and corrected the output signal generated by the optical encoders. The antenna position, combined with the pressure, temperature, and humidity data from the radiosonde, was used by the ground station to compute wind speed and direction. The receiver, control microprocessor, power supply, and switching array all were housed within the radiotheodolite. The radiosonde type used was a 1680-MHz Intellisonde, which was manufactured by A.I.R. The Intellisonde measured temperature, humidity, and pressure with digital precision. Sensor output was converted to digital words in the radiosonde. Pressure, temperature, humidity data, and sensor references were then formatted into a digital message. Contamination of pressure, temperature, and humidity data by telemetry noise was determined by error detection codes. ADRES is a Canadian rawindsonde system designed and produced by AES. It was in use for 20 years and is being phased out. The Pas was one of the last existing ADRES stations in Canada. ADRES was designed to partially automate upper-air soundings while allowing significant observer intervention. Significant and mandatory-level data were read manually from strip charts. The data were then entered manually and processed by the ADRES software. The observer was limited to a maximum of 60 levels. A 1680-MHz radiosonde was the instrument launched. The pressure was measured by means of a temperature-compensated single-cell aneroid. Temperature was measured using a thermistor. This thermistor was a thin rod of semiconductor ceramic material with a negative temperature coefficient of electrical resistance. Humidity was measured using an electrolytic element called a hygristor, whose electrical resistance varied proportionally to the relative humidity of the air. The hygristor consisted of a small plastic strip coated with a thin film of carbon. The two long edges were coated with metallic electrodes between which the resistance measurements were made. Candle Lake Surface Observation Instruments and Method ------------------------------------------------------ Dry and wet bulb temperatures were manually read from mercury in glass thermometers mounted in a nonventilated Stevenson screen. Depending on dew point temperature, the wet bulb thermometer was moistened using either a wick or a muslin sleeve. When the wet bulb temperature was greater than 0° C, a wick was used. A muslin sleeve was used when the wet bulb temperature ranged from 0 degrees C to -10 degrees C. The sleeve or wick was replaced once weekly. Temperature and dew point measurements were then corrected according to the factor specified by the thermometer serial number. Nonventilated psychrometric tables were used to determine dew point temperature and relative humidity after the correction had been applied. An instantaneous pressure value was manually taken using a Druck pressure sensor. No correction was applied. A 2-minute average of wind speed and direction was estimated by the observer. Wind direction was estimated in eight-point compass degrees. In 1996, a sling psychrometer was used to measure surface temperature and humidity. Wind speed and direction were taken as a 2-minute average measured electronically by an anemometer. Pressure was taken from an aneroid barometer. Thompson Surface Observation Instruments and Method --------------------------------------------------- Temperature and humidity were measured following the same procedure as at Candle Lake. The only difference was that the dry and wet bulb thermometers were in a ventilated Stevenson screen; therefore, ventilated psychrometric tables were used to determine dew point temperature and relative humidity. Two-minute averages of wind direction and speed were measured using the U2A wind measurement system. Direction was read to 10 degrees and speed to 1 knot. An instantaneous pressure value was manually read using a Setra 270 pressure sensor. No correction was applied. In 1996, a sling psychrometer was used to measure surface temperature and humidity. Wind speed and direction were taken as a 2-minute average measured electronically by an anemometer. Pressure was taken from a Setra pressure transducer. Key Lake and Churchill Surface Observation Instruments and Method ----------------------------------------------------------------- Temperature and humidity readings were taken by a READAC automatic weather station. The temperature sensor type was a thermistor, and the humidity sensor was a lithium chloride dew cell. Both were housed in a ventilated Stevenson screen 1.25 m above the ground. No corrections were applied. Pressure was measured via two Setra sensors; the lower of the two readings was output. Wind direction and speed were measured using 78D sensors. These sensors use vector averaging to calculate 2-minute wind direction and speed. In the event of automatic weather station failure, standard thermometers also housed in the READAC were used. If the wind sensors were not available, an estimation of wind direction was determined using the eight points of the compass, and wind speed was estimated in knots. No data were measured at Key Lake during BOREAS 1996. Surface observations at Churchill were not investigated for BOREAS 1996. The Pas Surface Observation Instruments and Method -------------------------------------------------- Temperature and humidity were measured in a ventilated Stevenson screen using a dew cell and thermistor. Temperature and dew point were displayed instantaneously. No correction was applied. Wind was measured using the same method as outlined for Thompson Zoo. Pressure was measured using a standard mercury barometer. No correction was applied. BOREAS 1996: In 1996, surface observations were not taken at The Pas. Saskatoon Surface Observation Instruments and Method ---------------------------------------------------- Temperature and wet bulb temperature were measured using a sling psychrometer. Relative humidity and dew point were determined via psychrometric tables. No corrections were applied. Pressure was measured by a Ruska digital barometer that was situated approximately 11 m higher than the radiosonde release point. A correction for this height discrepancy was applied during processing. Wind direction and speed were determined from the U2A output generated by the automatic weather station. Primrose Lake Surface Observation Instruments and Method -------------------------------------------------------- Temperature and dew point - same as at Candle Lake and Thompson Zoo (BOREAS 1994). Pressure sensor - displayed instantaneous pressure. Wind direction and speed were displayed instantaneously by dials or were determined from wind direction and speed plotted on a rolling strip chart. Two ordinary thermometers (same as at Candle Lake and Thompson Zoo for BOREAS 1994) were housed in a ventilated Stevenson screen. Dew point temperature was determined using the same method as at Candle Lake and Thompson Zoo, except that ventilated psychrometric tables were used to determine the relative humidity and dew point. It is unknown what procedure was followed regarding the wick/muslin sleeve or if corrections were applied for each thermometer. A 2-minute wind average was measured using a U2A instrument (as described for Thompson Zoo for BOREAS 1994). Winds may also have been observed from a strip chart produced by the U2A system. Pressure was measured using a standard mercury barometer. No correction was applied. 6. Observations 6.1 Data Notes Organized by date. Example: CANDL 94-Apr-13 11Z. CANDL= site ID, 94=Year, 04=Month, 13=Day of Month, 11Z=Hour during which the sonde was released (in UTC). THOMP=Thompson, CANDL=Candle Lake, PRIMR=Primrose Lake, CHURH=Churchill, THEPAS=The Pas, STOON=Saskatoon, LYNNL=Lynn Lake, KEY L=Key Lake. -KEY L 94-Apr-12 17Z: Early burst, second release performed. -CANDL 94-Apr-13 11Z: RH incorrectly calculated using a correction for wet bulb of -1.0 instead of -0.1. RH was entered as 41% instead of 54%. Dew point may be recorded incorrectly. -CANDL 94-Apr-13 17Z: Dew point may be incorrect. 94-Apr-14 11Z: Light snow at release time, turning into heavy snow, quit at 1230. Local power surge followed by outage at 11:32, 11:33, 11:45, and 12:02. Outage at 12:02 - remained out until flight terminated. -STOON 94-Apr-13 17Z: No wind data. -STOON 94-Apr-13 23Z: No wind data. -STOON 94-Apr-14 23Z: Computer lost sonde signal. -STOON 94-Apr-15 23Z: No flight information - radiosonde technical problems. -CANDL 94-Apr-16 17Z: String connecting radiosonde to balloon did not appear to unwind fully. -STOON 94-Apr-16 11Z: No flight information - radiosonde technical problems. -STOON 94-Apr-16 17Z: No flight information - radiosonde technical problems. -THOMP 94-Apr-18 11Z: Lost signal - unable to find. -THOMP 94-Apr-19 11Z: Old-looking balloon. -THOMP 94-Apr-19 17Z: Old-looking balloon. -THOMP 94-Apr-20 17Z: Lost signal for a while. -CANDL 94-Apr-21 11Z: String did not appear to unwind. -KEY L 94-Apr-21 11Z: This flight was very short. The balloon had burst at 49 min 20 sec. -KEY L 94-Apr-22 11Z: This flight was unsuccessful due to an early burst. Second release will be performed. -THOMP 94-Apr-22 11Z: Second launch. -CANDL 94-Apr-23 11Z: String did not appear to unwind. -KEY L 94-Apr-23 11Z: Poor weather and poor visibility delayed arrival to site (about 5 AM). -CANDL 94-Apr-24 11Z: Problem with wet bulb temperature; therefore, RH was entered at 72%, which was the local Environment Canada calculation at 10:00Z. -KEY L 94-Apr-24 11Z: Balloon burst early at 38 min 30 sec. -THOMP 94-Apr-24 11Z: Had problems with signal between 90 mb and 60 mb. -THOMP 94-Apr-24 17Z: Lost signal between 232 mb and 192 mb. -STOON 94-Apr-25 17Z: Manual flight end. -THOMP 94-Apr-25 11Z: Lost signal for a while. -THOMP 94-Apr-25 17Z: Lost signal for a while. -THOMP 94-Apr-25 11Z: Lost signal for a while. -CANDL 94-Apr-26 11Z: Problem with RH -- METHOD? -KEY L 94-Apr-26 17Z: Flight was unsuccessful due to an early burst; a second release will be performed. -THOMP 94-Apr-26 11Z: Lost wind direction and speed for a while. -THOMP 94-Apr-26 17Z: Lost signal around 90 mb. -KEY L 94-Apr-27 17Z: Flight was unsuccessful due to an early burst; a second release will be performed. -THOMP 94-Apr-27 11Z: First radiosonde rejected. Surface temperature should be -10.0 instead of 10.0. -CANDL 94-Apr-28 11Z: String did not appear to unwind. -STOON 94-Apr-28 17Z: No wind data. -CANDL 94-Apr-29 11Z: String did not appear to unwind. -KEY L 94-Apr-30 11Z: Flight was delayed due to a defective balloon. -THOMP 94-Apr-30 17Z: Clock set on Digicora and computer. -THOMP 94-May-02 11Z: Radiosonde temperature gauge broken. Unable to make a copy of the April 30 diskette. Having trouble with telemetry, Digicora said that data were out of bounds. Monitoring sonde returned. Lost wind direction and speed at 94.2 mb. -CANDL 94-May-24 11Z: Balloon had a visible weak spot on one side but it did not seem to have any effect. -CANDL 94-May-24 23Z: Radiosonde failure. -KEY L 94-May-24 11Z: Flight was unsuccessful. Second release will be performed. There was missing data for wind direction/speed (5 min 25 sec to 11 min 35 sec, 12 min 15 sec to 17 min 45 sec, and 20 min 55 sec to termination). Range missing from 5 min 25 sec to termination. -KEY L 94-May-24 17Z: There was an electrical outage from 9:30AM(CST) to 11:45AM (CST). Because there was no power, the automatic weather station was inoperative. The surface weather observation was taken manually from the Stevenson screen barometer, wind charts, and psychrometric tables. -CANDL 94-May-25 11Z: String did not unwind. -CANDL 94-May-25 20Z: Relaunch just after 20:00Z because two bad humidities on sondes forced two relaunches. Authorized by Alan Betts. -CANDL 94-May-25 21Z: MW15 possibly picked up another instrument still in the air even though radio frequencies of the second release was 401.38. Flight automatically ended at 21:50Z. No second release attempt due to time constraints. -KEY L 94-May-25 11Z: Flight was delayed due to radiosonde difficulties. The first one was rejected due to a high humidity reading (153%). The second and third radiosondes give similar readings but did not correspond within range for the READAC's observations. The second and third radiosondes were giving acceptable readings. Since there was very little time, the Stevenson screen was used for the temperature, dew point, and RH. The radiosonde was an unacceptable range in relation to the Stevenson screen. The psychrometric table was unclear to what the RH factor was. 49% was used for the observation. -THOMP 94-May-25 11Z to 94-Jun-06 15Z: No wind information. -CANDL 94-May-26 19Z: Manual termination due to bad data. 100% RH and bad temperature. -THPAS 94-May-26 17Z: Strong convection, lots of ascent rate changes and superadiabatic layers. -THPAS 94-May-26 23Z: Many supers off surface (7). MISDA STRATUM DUESCT. SGN. NO APPARENT CAUSE.?? -KEY L 94-May-27 23Z: Flight was unsuccessful due to an early burst. Second release will be performed. -THPAS 94-May-27 11Z: Many supers!! -THPAS 94-May-27 17Z: Many supers!!! -STOON 94-May-28 19Z: Second launch. -THPAS 94-May-28 17Z: Many supers. Ground equipment trouble delayed release. -CANDL 94-May-29 11Z: No wind data until 484hPa. Winds lost again at 250hPa. -CANDL 94-May-29 19Z: Flight released at 19:03Z at Alan Betts' request. Rain showers approaching. -CANDL 94-May-29 21Z: Flight released at 21:08 at Alan Betts' request. -CANDL 94-May-30 11Z: No wind data until 544.9hPa. -CANDL 94-Jun-01 11Z: Balloon has a very irregular shape. No wind data until 862hPa. -CANDL 94-Jun-01 15Z: No wind data until 794hPa. -KEY L 94-Jun-03 11Z: Flight was unsuccessful. Second release will be performed. There was missing data for wind direction/speed (6 min 5 sec to 15 min 55 sec and 17 min 25 sec to termination. Range missing from 6 min 5 sec to termination.) -THPAS 94-Jun-03 17Z: Power failure near end. ADRES used to finish. -CANDL 94-Jun-04 11Z: Odd-shaped balloon. Balloon was touching top of tent - may be over 500 grams. -KEY L 94-Jun-04 11Z: Flight came very close to being delayed because the READAC's observations were not corresponding within range with the radiosondes. Three radiosondes were compared with the READAC's observations. All three gave similar readings but were slightly out of range with the READAC. The radiosonde was in range with the Stevenson screen. The READAC was also not giving wind observations. The winds were estimated for direction and speed. -KEY L 94-Jun-04 17Z: Flight was unsuccessful. Second release will be performed. There was missing data for wind data from 30 min 25 sec to termination. -KEY L 94-Jun-05 11Z: Flight was unsuccessful because the receiver had lost the signal from the sonde. Second release will be performed. -KEY L 94-Jun-05 17Z: Flight was unsuccessful because the receiver had lost the sonde's signal. Second release will be performed. -THPAS 94-Jun-05 11Z: Many supers off surface. -THPAS 94-Jun-05 23Z: Instrument hit CB base. -CANDL 94-Jun-06 11Z: String did not unwind. -KEY L 94-Jun-07 11Z: Flight was unsuccessful. There was missing wind data from 22 min 35 sec to termination. Second release will be performed. -CANDL 94-Jun-08 11Z: Approximately 20 minutes into the flight TELEM became very weak - RH jumping from 8% to 160%. Flight ended - second release. -CANDL 94-Jun-08 12Z: String did not fully unwind. TELEM problems. -CANDL 94-Jun-08 19Z: String did not appear to unwind all the way. -KEY L 94-Jun-08 12Z: Surface wind direction and speed were estimated. This was required because the READAC was giving no wind observations. -CANDL 94-Jun-09 11Z: String did not unwind fully. -CANDL 94-Jun-10 11Z: Balloon slightly lopsided. Didn't look like string unwound all the way. -CANDL 94-Jun-10 19Z: Signal very weak. -KEY L 94-Jun-10 11Z: The sonde was not in range with the READAC. Three sondes were tried and compared to the READAC, but all were out of range. All three sondes were giving similar readings. Stevenson screen was compared to the sondes and was found to be within range. -STOON 94-Jun-10 19Z: Third launch. First launch - lost signal and ended flight. Second launch - couldn't locate sonde. -CANDL 94-Jun-11 11Z: String unwound only as far as the plastic antennae cord and then stopped. -KEY L 94-Jun-11 12Z: Flight was unsuccessful. Flight ended at about 13:20 Greenwich Mean Time (GMT). Because there was little time left, a third release was not performed. There was missing wind data from 11 min 55 sec to termination. -KEY L 94-Jun-11 23Z: Flight was unsuccessful due to an early burst. Second release will be performed. -KEY L 94-Jun-12 11Z: Unsuccessful flight. Second release will be performed. There was missing wind data from 25 min 45 sec to termination. -KEY L 94-Jun-12 23Z: A power outage made the READAC inoperative. Observations were taken manually. -CANDL 94-Jun-13 11Z: String did not fully unwind. -CANDL 94-Jun-13 23Z: String unwound only to end of plastic cord (again). -STOON 94-Jun-13 00Z: Second launch. First launch - sonde not located at launch. -PRIMR 94-Jun-14 17Z: Balloon defect. -STOON 94-Jun-14 23Z: Second launch. First launch - sonde not located at launch. -CANDL 94-Jun-15 13Z: String did not unwind at launch. -CANDL 94-Jun-15 15Z: String did not unwind at launch. -CANDL 94-Jun-15 17Z: String did not unwind at launch. -CANDL 94-Jun-15 19Z: String did not unwind at launch. -KEY L 94-Jun-15 23Z: Surface observations taken manually. The READAC was not online. -PRIMR 94-Jun-15 12Z: Balloon burst. -STOON 94-Jun-15 18Z: Second launch. First launch - sonde not located at launch. -STOON 94-Jun-15 23Z: Second launch. First launch - sonde not located at launch. -THOMP 94-Jun-15 11Z: Snow, rain, and fog outside. -CANDL 94-Jun-16 11Z: String unwound only to end of plastic cord. -CANDL 94-Jun-16 13Z: String only partially unwound. -KEY L 94-Jun-16 11Z: Flight delayed - alarm clock failed to go off. -STOON 94-Jun-16 23Z: Second launch. First launch - sonde not located at launch. -THPAS 94-Jul-18 23Z: 5 supers. -CANDL 94-Jul-19 11Z: Early burst. -CANDL 94-Jul-19 12Z: Second release. Early burst?? -CANDL 94-Jul-19 12Z: Third release. Early burst?? -CANDL 94-Jul-19 23Z: Technical problems delayed release. -STOON 94-Jul-19 18Z: Second release. First release - lost sonde signal at launch. -THOMP 94-Jul-19 11Z: Second release. Technical problems on first release. -THPAS 94-Jul-19 11Z: Late release. -KEY L 94-Jul-21 23Z: Loran reception was very poor. This caused a large amount of wind data loss. -LYNNL 94-Jul-21 11Z: National Scientific Balloon Facility (NSBF) balloon: used a special, large mylar balloon to obtain high-altitude wind data above 5 mb. -STOON 94-Jul-21 18Z: Second release. First release - lost sonde signal at launch. -CHURH 94-Jul-22 11Z: No winds. -STOON 94-Jul-22 00Z: Second release. First release - lost sonde signal at launch. -CHURH 94-Jul-23 11Z: Second release. No flight - equip. fail. -KEY L 94-Jul-23 11Z: Loran reception was very poor. This caused a large amount of wind data loss. -THPAS 94-Jul-23 23Z: 5 supers. -CHURH 94-Jul-24 11Z: Second release. -KEY L 94-Jul-24 23Z: Flight was unsuccessful. Second release will be performed. There was missing wind data from 7 min 45 sec to 22 min 45 sec and 33 min 55 sec to termination. -THPAS 94-Jul-24 23Z: 5 supers. -CANDL 94-Jul-25 11Z: Surface data entered in error as 66% (correct RH not available). -CHURH 94-Jul-25 11Z: No winds. -LYNNL 94-Jul-25 11Z: NSBF high altitude balloon. -STOON 94-Jul-25 11Z: Second launch - lost sonde signal at launch. -THPAS 94-Jul-25 17Z: Early release - observer error. -STOON 94-Jul-26 13Z: Third release. First and second release - lost sonde signal at launch. -CANDL 94-Jul-27 19Z: 2 low ascent rates - balloons inflated the same as usual. -CHURH 94-Jul-27 12Z: Second release. No winds for first release. -KEY L 94-Jul-27 17Z: No wind data. -STOON 94-Jul-27 00Z: Second release. First release - lost sonde signal at launch. -STOON 94-Jul-27 12Z: Second release. First release - lost sonde signal at launch. -THPAS 94-Jul-27 17Z: 4 supers. -THPAS 94-Jul-27 23Z: 6 supers. -LYNNL 94-Jul-28 11Z: Special NSBF balloon. -LYNNL 94-Jul-29 11Z: Special NSBF balloon. -STOON 94-Jul-29 12Z: Second release. First release - lost sonde signal at launch. -STOON 94-Jul-30 11Z: No winds. Second release required. -STOON 94-Jul-30 12Z: Third release. Second release - lost sonde signal at launch. -STOON 94-Jul-30 18Z: Second release. First release - lost sonde signal at launch. -STOON 94-Jul-31 18Z: Three attempts to release - lost sonde signal at launch for all three. No flight information. -STOON 94-Aug-01 00Z: Second release. First release - lost sonde signal at launch. -STOON 94-Aug-01 14Z: Third release. First and second release - lost sonde signal at launch. -THPAS 94-Aug-01 11Z: 3 supers. -PRIMR 94-Aug-02 12Z: No flight due to conflict with range operations. -STOON 94-Aug-02 12Z: Second release. First release - lost sonde signal at launch. -THOMP 94-Aug-02 13Z: Launch delayed. Operator had to wait for approval from flight control until 13:42Z; then when balloon released, the twine between the balloon and the sonde broke. The sonde was damaged in the fall. Second release made. -THOMP 94-Aug-02 19Z: Launch delayed by air traffic control. -THPAS 94-Aug-02 11Z: 3 supers. -KEY L 94-Aug-03 17Z: Flight was unsuccessful. There was missing wind data from 0 min 5 sec to 5 min 5 sec, 5 min 25 sec to 10 min 15 sec, 16 min 45 sec to 28 min 15 sec, 28 min 55 sec to 34 min 25 sec, and 34 min 35 sec to termination. Second release will be performed. -LYNNL 94-Aug-03 11Z: Special NSBF balloon. No data recorded for first run. -PRIMR 94-Aug-03 12Z: No flight due to conflict with range operations. -STOON 94-Aug-03 11Z: Second release. First release - lost sonde signal at launch. -STOON 94-Aug-03 18Z: Second release. First release - lost sonde signal at launch. -KEY L 94-Aug-04 23Z: Flight was unsuccessful; there was missing wind data from 7 min 15 sec to termination. Second release will be performed. -PRIMR 94-Aug-04 and 94-Aug-05: No flights due to base commitments. -STOON 94-Aug-04 12Z: Second release. First release - lost sonde signal at launch. -THPAS 94-Aug-04 17Z: 2 supers. -THPAS 94-Aug-04 23Z: 4 supers. -LYNNL 94-Aug-05 11Z: Special NSBF balloon. -THOMP 94-Aug-05 15Z: Launch delayed by air traffic control. -THPAS 94-Aug-05 17Z: 2 supers. -THPAS 94-Aug-05 23Z: 4 supers. -STOON 94-Aug-06 13Z: Second release. First release - lost sonde signal at launch. -STOON 94-Aug-06 23Z: Flight lost - terminated and disk save. -THOMP 94-Aug-06 11Z: Not able to make this flight as keys to the zoo had been lost during the evening. Not able to access the zoo until 9AM. -LYNNL 94-Aug-07 11Z: Special NSBF balloon. -THPAS 94-Aug-07 17Z: 6 supers. -PRIMR 94-Aug-08 17Z: Flight ended at 200 mb (low-stability sonde used). -STOON 94-Aug-08 23Z: Omega tracking. Winds mostly missing. -THPAS 94-Aug-08 17Z: 6 supers. -STOON 94-Aug-09 01Z: Omega tracking. Second launch. -THPAS 94-Aug-30 17Z: 6 supers. -THPAS 94-Aug-30 23Z: 6 supers. -STOON 94-Aug-31 17Z: No wind data. -THPAS 94-Aug-31 11Z: 1 super. -THPAS 94-Aug-31 17Z: 5 supers. -THPAS 94-Aug-31 23Z: 7 supers. -STOON 94-Sep-01 11Z: No wind data. -THPAS 94-Sep-01 17Z: 1 super. -THPAS 94-Sep-01 23Z: 4 supers. -STOON 94-Sep-02 11Z: No wind data. -STOON 94-Sep-02 17Z: No wind data. -THPAS 94-Sep-02 17Z: 1 super. -THPAS 94-Sep-02 23Z: 4 supers. -STOON 94-Sep-03 12Z: Second launch. First launch - stuck in monitoring for launch mode. -THOMP 94-Sep-03 12Z: Sonde late because Charles Fenner (operator) did not show up. Launched by Alan Betts and Jo Lutley. -THPAS 94-Sep-03 17Z: Power failure - ADRES crash. ADRES used to finish. No winds. -THPAS 94-Sep-04 23Z: 1st release at 23:15 failed due to G.E.F. -KEY L 94-Sep-07 11Z: Flight was unsuccessful due to a signal loss. Second release will be performed. Surface observations were taken manually because the READAC was not giving any data due to a hard disk drive failure. -KEY L 94-Sep-07 13Z: Flight was delayed because the computer had difficulties sending out the UM, UG, UF, and UQ data. Observations were taken manually because the READAC still had a hard disk drive failure. As of 13:50 GMT, security reports the READAC in good working order and READAC observations will be available for the 18:00 Zulu flight. -THOMP 94-Sep-07 23Z: Surface RH needs correction in data: to 54% - wick was loose. -STOON 94-Sep-08 00Z: Second launch. First launch - sonde located; monitor for launch mode. -THPAS 94-Sep-08 13Z: Late release - operator slept in. -CANDL 94-Sep-10 15Z: Late because first sonde had bad humidity. Weak telemetry. -KEY L 94-Sep-10 11Z: Flight was delayed because the first radiosonde would not give any surface weather conditions. Receiver indicated no signal even though the radiosonde was transmitting a strong signal. This radiosonde was rejected. The second radiosonde was good. -STOON 94-Sep-10 01Z: Second launch. First launch - sonde located; monitor for launch mode. -STOON 94-Sep-10 13Z: Second launch. -THPAS 94-Sep-10 11Z: 4 supers. -THPAS 94-Sep-10 17Z: 4 supers. -THPAS 94-Sep-10 23Z: 3 supers. Missing RH 960 mb to 896 mb. -KEY L 94-Sep-11 11Z: Surface observations were taken manually because the READAC was not online with the security gate house. -KEY L 94-Sep-11 17Z: Surface observations were taken manually because the READAC still remains inoperative. -THPAS 94-Sep-11 23Z: 2 supers. -THPAS 94-Sep-12 17Z: 1 super. Transponder sonde. -THPAS 94-Sep-12 23Z: 2 supers. -THPAS 94-Sep-13 11Z: 2 supers. -KEY L 94-Sep-14 11Z: No flight was performed because there were no radiosondes. Radiosondes were shipped out during the middle of last week but still have not arrived at Key Lake. -THPAS 94-Sep-14 23Z: 5 supers. -THPAS 94-Sep-14 11Z: 3 supers. -STOON 94-Sep-15 23Z: Loran tracking starts. -THPAS 94-Sep-15 23Z: 3 supers. -CANDL 94-Sep-16 11Z: No wind at surface - darkness - couldn't see balloon. -THOMP 94-Sep-16 11Z: No flight (no explanation provided). -CHURH 94-Sep-17 12Z: Second release. -THPAS 94-Sep-17 11Z: 4 supers. -THPAS 94-Sep-18 17Z: 2 supers. -THPAS 94-Sep-18 23Z: 6 supers. -STOON 94-Sep-19 19Z: Second launch. First launch - flight went into disk save immediately. -CANDL 96-Jul-08 17Z: Sfc P entered incorrectly at release time. Changed manually from 967.3 to 966.3 (correction of -0.69 not applied to 966.3 because it was already applied in the field). Correction of -0.69 applied to the surface pressure as indicated on the barometer for the soundings listed below. Those not on the list below were corrected by the flight operator at the time of release. 96-Jul-09 15Z, 96-Jul-09 17Z, 96-Jul-09 21Z, 96-Jul-09 23Z, 96-Jul-10 11Z, 96- Jul-10 15Z, 96-Jul-10 17Z, 96-Jul-10 19Z, 96-Jul-10 21Z, 96-Jul-10 23Z, 96-Jul-11 11Z, 96- Jul-11 17Z, 96-Jul-11 23Z, 96-Jul-13 11Z, 96-Jul-13 15Z, 96-Jul-13 17Z, 96-Jul-13 19Z, 96- Jul-13 21Z, 96-Jul-13 23Z, 96-Jul-14 11Z, 96-Jul-14 15Z, 96-Jul-14 17Z, 96-Jul-14 19Z, 96- Jul-14 20Z, 96-Jul-14 21Z, 96-Jul-14 23Z, 96-Jul-15 11Z, 96-Jul-15 15Z, 96-Jul-15 17Z, 96- Jul-15 19Z, 96-Jul-15 21Z, 96-Jul-15 23Z, 96-Jul-16 11Z, 96-Jul-16 17Z, 96-Jul-16 23Z, 96- Jul-17 11Z, 96-Jul-17 17Z, 96-Jul-17 19Z, 96-Jul-17 21Z, 96-Jul-17 23Z, 96-Jul-18 11Z, 96- Jul-18 17Z, 96-Jul-18 23Z, 96-Jul-19 11Z, 96-Jul-19 17Z, 96-Jul-19 19Z, 96-Jul-19 21Z, 96- Jul-19 23Z, 96-Jul-20 11Z, 96-Jul-20 15Z, 96-Jul-20 17Z, 96-Jul-20 19Z, 96-Jul-20 21Z, 96- Jul-20 23Z, 96-Jul-21 11Z, 96-Jul-21 17Z, 96-Jul-21 23Z, 96-Jul-22 11Z, 96-Jul-22 15Z, 96- Jul-22 17Z, 96-Jul-22 19Z, 96-Jul-22 21Z, 96-Jul-22 23Z, 96-Jul-23 11Z, 96-Jul-23 17Z, 96- Jul-23 23Z, 96-Jul-24 11Z, 96-Jul-24 15Z, 96-Jul-24 17Z, 96-Jul-24 19Z, 96-Jul-24 21Z, 96- Jul-24 23Z, 96-Jul-25 11Z, 96-Jul-25 15Z, 96-Jul-25 17Z, 96-Jul-25 18Z, 96-Jul-25 23Z, 96- Jul-29 11Z, 96-Jul-29 15Z, 96-Jul-29 17Z, 96-Jul-29 19Z, 96-Jul-29 21Z, 96-Jul-29 23Z, 96- Jul-30 11Z, 96-Jul-30 15Z, 96-Jul-30 17Z, 96-Jul-30 19Z, 96-Jul-30 21Z, 96-Jul-30 23Z, 96- Jul-31 11Z, 96-Jul-31 15Z, 96-Jul-31 17Z, 96-Jul-31 23Z, 96-Aug-01 11Z, 96-Aug-01 15Z, 96- Aug-01 17Z, 96-Aug-01 19Z, 96-Aug-01 21Z, 96-Aug-01 23Z, 96-Aug-02 11Z, 96-Aug-02 15Z, 96- Aug-02 17Z, 96-Aug-02 19Z, 96-Aug-02 21Z, 96-Aug-02 23Z, 96-Aug-03 11Z, 96-Aug-03 17Z, 96- Aug-03 23Z, 96-Aug-04 11Z, 96-Aug-04 17Z, 96-Aug-04 23Z, 96-Aug-05 11Z, 96-Aug-05 17Z, 96- Aug-05 23Z. -CANDL 96-Jul-09 11Z: No data available - software and technical problems during sounding. -THOMP 96-Jul-09 23Z: First and only flight done that day because helium for balloons had not been delivered until late in the day. -THPAS 96-Jul-09 11Z: Removed excess error messages in Flight Log (JNL) file. -THPAS 96-Jul-09 23Z: RH too high; thermo data missing between 3 and 7 min. -THOMP 96-Jul-10 19Z: Vaisala RH bad - removed flight from archive. -STOON 96-Jul-10 23Z: Sonde signal lost prior to launch - picked up again at 926.63 mb. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Jul-11 23Z: Possibly poor signal above 500 mb - reflected in thermo data. P increases and decreases alternately from approximately 14.4 to 16.03 min. Full-resolution file archived, but an interpolated version was not produced. -THPAS 96-Jul-11 11Z: Removed excess error messages in Flight Log (JNL) file. -STOON 96-Jul-12 11Z: Possibly poor signal - reflected in thermo data. Out-of- range wind speed at 4 min. -THOMP 96-Jul-12 23Z: Temperature and humidity probably interpolated by the Vaisala system from surface to approx. 950 mb. -THOMP 96-Jul-13 15Z: Sfc RH entered incorrectly at launch time. Replaced the original value of 25% with 48% (which was the value shown in the surface observation log just prior to release). -CANDL 96-Jul-14 20Z: Flight ended at 2 min 12 sec. Although this flight was released during the hour of 21Z, it was named 20Z so as not to be confused with the second release, which was also launched during the hour of 21Z. -CANDL 96-Jul-17 17Z: Vaisala humidity probably too high. -THOMP 96-Jul-18 19Z: Surface RH probably too high - correction NOT applied. -STOON 96-Jul-20 11Z: Bad pressure data - removed flight from archive. -STOON 96-Jul-20 23Z: No wind info. -THOMP 96-Jul-20 11Z: Temperature probably interpolated by the Vaisala system from surface to approx. 900 mb. -THOMP 96-Jul-21 23Z: Temperature and humidity possibly interpolated by the Vaisala system from surface to approx. 880 mb. -THPAS 96-Jul-21 23Z: Launch and End of Flight time edited manually in Flight Log (JNL) file. -THOMP 96-Jul-25 17Z: Sfc P incorrect - should have been 998.9 rather than 989.9. Corrected this problem by adding 9 to all pressure measurements in the sounding. -CANDL 96-Jul-26 22Z: Flight ended at 18 min. Although this flight was released during the hour of 23Z, it was named 22Z so as not to be confused with the second release, which was also launched during the hour of 23Z. -STOON 96-Jul-26 11Z: Excess error messages in Flight Log (JNL) file removed manually. -THPAS 96-Jul-26 23Z: End of Flight time edited manually in Flight Log (JNL) file. -THOMP 96-Jul-27 22Z: Flight ended at 6 min 56 sec. Although this flight was released during the hour of 23Z, it was named 22Z so as not to be confused with the second release, which was also launched during the hour of 23Z. -STOON 96-Jul-28 11Z: Launch and End of Flight time edited manually in Flight Log (JNL) file. -THOMP 96-Jul-28 23Z: Sfc wet bulb temperature (of 16.4) accidentally entered into the u/a system instead of the actual surface temp of 24.6. This has been corrected. -CANDL 96-Jul-29 11Z: Sfc P entered incorrectly at release time. Changed manually from 964.1 to 963.1 (then -0.69 applied to 963.1). -THOMP 96-Jul-29 17Z: Sfc P incorrect - should have been 998.9 rather than 989.9. Corrected this problem by adding 9 to all pressure measurements in the sounding. Temperature and humidity possibly interpolated by the Vaisala system from surface to approximately 930 mb. Sfc RH also incorrect. Wet bulb temperature entered into the system instead of RH by mistake. Observed RH=79%. Unfortunately, the Vaisala system interpolated RH from the surface to approximately 930 mb using the incorrect RH (of 19%) as the starting point. Removed levels starting with the first above-surface level to 940.2 mb. -STOON 96-Jul-30 23Z: P increases for a few levels near 50.4 minutes. P increases and decreases alternately from approximately 76.05 to 76.67 min. Full-resolution file archived, but an interpolated version was not produced. -THPAS 96-Jul-31 11Z: Launch time edited manually in Flight Log (JNL) file. -STOON 96-Aug-01 11Z: Launch time edited manually in Flight Log (JNL) file. -STOON 96-Aug-02 11Z: Launch time edited manually in Flight Log (JNL) file. -THPAS 96-Aug-03 23Z: First pressure following surface was higher than the surface pressure. Removed this level. -STOON 96-Aug-05 11Z: Excess error messages in Flight Log (JNL) file removed manually. -STOON 96-Aug-05 23Z: Launch time edited manually in Flight Log (JNL) file. -THPAS 96-Aug-05 11Z: Sonde signal lost prior to launch - picked up again at 921.21 mb. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Aug-06 23Z: Out-of-range wind speeds near end of flight. -THOMP 96-Aug-07 19Z: Manually measured sfc T/RH very different from Vaisala T/RH - possibly because ob. taken 28 min prior to launch. Replaced sfc T/RH with HMP (autostation) values. -STOON 96-Aug-08 11Z: No temperature data. -CHURH 96-Oct-01 11Z: Errors in original site diskette. Repaired file but was unable to convert to American Standard Code fpr Information Interchange (ASCII). -STOON 96-Oct-04 23Z: Sonde signal lost prior to launch - picked up again at 896.7 mb. Time (sec) in raw file: 1326.5 P=945.78 (before lost signal) ---> then skipped to: 1599.7 P=896.7 (when signal found again). Assumed that launch occurred somewhere in between. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Oct-05 11Z: End of Flight message patched into Flight Log (JNL) file. -STOON 96-Oct-08 11Z: Sonde signal lost prior to launch - picked up again at 896.7 mb. Time (sec) in raw file: 142.6 P=955.19 (before lost signal) ---> then skipped to: 274.4 P=907.63 (when signal found again). Assumed that launch occurred somewhere in between. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Oct-08 23Z: End of Flight message patched into Flight Log (JNL) file. -STOON 96-Oct-09 11Z: Sonde signal lost prior to launch - picked up again at 731.6 mb. Time (sec) in raw file: 67.6 =962.41 (before lost signal) ---> then skipped to: 493.3 P=731.6 (when signal found again). Assumed that launch occurred somewhere in between. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Oct-11 11Z: Removed P=971.48 at 1560.5 sec in raw file. P goes bad after approx. 6 min. Removed from archive. -STOON 96-Oct-12 11Z: End of Flight message patched into Flight Log (JNL) file. Sonde signal lost prior to launch - picked up again at 939.8 mb. Time (sec) in raw file: 2316.2 P=952.72 (before lost signal) ---> then skipped to: 2350.9 P=939.8 (when signal found again). Assumed that launch occurred somewhere in between. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Oct-14 11Z: Possibly a poor signal between 750 and 475 mb. -STOON 96-Oct-14 23Z: Flight not available. -STOON 96-Oct-15 11Z: Flight not available. -THPAS 96-Oct-15 23Z: End of Flight message patched into Flight Log (JNL) file. -STOON 96-Oct-16 23Z: Sonde signal lost prior to launch - picked up again at 667.86 mb. Time (sec) in raw file: 0.0 P=955.2 (before lost signal) ---> then skipped to: 12.9 P=667.86 (when signal found again). Assumed that launch occurred somewhere in between. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Oct-17 11Z: Sonde signal lost prior to launch - picked up again at 949.54 mb. Time (sec) in raw file: 124.1 P=960.97 (before lost signal) ---> then skipped to: 156.3 P=949.54 (when signal found again). Assumed that launch occurred somewhere in between. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Oct-17 23Z: Full-resolution data not archived. Significant and mandatory levels available. -STOON 96-Oct-18 11Z: Sfc P incorrect. Sfc P at YXE (airport) = 1012.7. Probably P was entered as 905.7, instead of 950.7. Used P=949.9, which was taken approx. 30 min prior to release. -THPAS 96-Oct-18 23Z: Flight data file n/a - used a hardcopy version of significant and mandatory-level data. -STOON 96-Oct-19 00Z: Sonde signal lost prior to launch - picked up again at 920.52 mb. Time (sec) in raw file: 2058.1 P=938.19 (before lost signal) ---> then skipped to: 2094.0 P=920.52 (when signal found again). Assumed that launch occurred somewhere in between. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Oct-19 23Z: Edited a bogus "Launch Detected" time into Flight Log (JNL) file. Also, an extra "Operator Edited Launch" message removed from Flight Log (JNL). -THPAS 96-Oct-19 11Z: Full-resolution thermo data file not available. Used significant and mandatory-level data. -STOON 96-Oct-20 11Z: Sonde signal lost prior to launch - picked up again at 948.3 mb. Time (sec) in raw file: 1463.3 P=956.54 (before lost signal) ---> then skipped to: 1509.0 P=948.3 (when signal found again). Assumed that launch occurred somewhere in between. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate -STOON 96-Oct-21 11Z: Sonde signal lost prior to launch - picked up again at 916.94 mb. Time (sec) in raw file: 1486.2 P=961.75 (before lost signal) ---> then skipped to: 1595.9 P=916.94 (when signal found again). Assumed that launch occurred somewhere in between. Applied a correction to elapsed time by determining the ascent rate using the 1st and 20th observation (following the surface ob.) AscentRate=(Height2-Height1)/(Time2-Time1) TimeToAdd=(Height1-SiteElev.)/AscentRate 6.2 Field Notes None. See Section 6.1. 7. Data Description 7.1 Spatial Characteristics 7.1.1 Spatial Coverage The upper-air data were recorded from several stations that span the BOREAS study region. The North American Datum of 1983 (NAD83) corner coordinates of the 1,000- x 1,000-km BOREAS study region are: Latitude Longitude Northwest 59.97907 N 111.00000 W Northeast 58.84379 N 93.50224 W Southwest 51.00000 N 111.00000 W Southeast 50.08913 N 96.96951 W The descriptions of the individual launch sites follow: Candle Lake (BOREAS 1994 and 1996) ---------------------------------- The Vaisala Digicora II MW15 was located inside the Sno-Drifters Lodge on the Recreation Center grounds. The building used to inflate the balloons (1994 only) was located on the west side of the Sno-Drifters Lodge. The Sno-Drifters Lodge was in the northeast corner of a somewhat rectangular clearing measuring approximately 260 m wide and 170 m across. The clearing was surrounded by 12- to 15-m-tall trees of a mixed variety. The Stevenson screen (BOREAS 1994) was located along the northern edge of the clearing about 9 m away from the Sno-Drifters Lodge. The exposure was nonstandard because more appropriate spots near the lodge were used as fuel caches and as a helicopter landing pad. The surrounding topography was somewhat hilly boreal forest with a mixture of coniferous and deciduous trees with three lakes nearby oriented in a NW to SE direction. Candle Lake was 17 km long and 12 km wide (at the widest) and was located approximately 1.5 km to the north. Torch Lake was 8 km long and 2.5 km wide and lie approximately 500 to 600 m to the west. There was a nameless small body of water 3 km long and 700 m wide 250 m east of the release site. In 1996, surface temperature and humidity were measured using a sling psychrometer, away from the Sun's radiation. Wind direction and speed were measured (not estimated) at a fixed point by an RM Young anemometer, approximately 4 m above the ground. Northerly wind direction and speed at Candle Lake may have been obstructed or altered by trees or the Sno-Drifters Lodge. Thompson Zoo ------------ The instruments were housed on the mezzanine floor of the Thompson Zoo operations building. The release area was located at the south end of the zoo operations building. This area was flat and unobstructed to the south and east. Obstructions to release included the two-story zoo building to the north and electrical lines to the west. The observers had the opportunity to maneuver around these obstructions by releasing from the north side of the operations building. The receiving antennae were located on the roof of the operations building and as a result were unobstructed in all directions. In 1996, surface temperature and humidity were measured using a sling psychrometer, away from the Sun's radiation. Wind direction and speed were measured (not estimated) at a fixed point by an RM Young anemometer, approximately 4 m above the ground. There were no major obstructions to the anemometer wind direction and speed. Key Lake (BOREAS 1994) ---------------------- The Vaisala Digicora II MW15 was located in an office in the terminal building at the Key Lake airport. The instruments associated with the READAC were located on a level, open sandy area with sparse grass cover at the Key Lake Mine airport. The instrument area consisted of a 90 x 90 m clearing in an old burn area. The clearing was surrounded by 2 to 3 m tall jack pine. The balloon inflation shed was southeast of the READAC instrument area near the airport terminal building. The surrounding countryside was jack pine forest with rolling hills and an occasional small lake. Saskatoon (BOREAS 1994 and 1996) -------------------------------- The VIZ W9000 system and pressure sensor were located in the Saskatchewan Environmental Services Center (third floor) in Saskatoon. The instrument used to observe wind speed and direction was mounted on a tower on the roof of the building housing the weather services office (approximately 15 m above the ground). The release site was within a baseball diamond located approximately 200 m from the VIZ system. The balloon inflation site was in a storage building next to the release site. Surface sling psychrometer observations were taken outside of the storage building. The release site was unobstructed. Primrose Lake (BOREAS 1994) --------------------------- Two different sites were used for release at Primrose Lake. Most of the balloons were released on top of a hill overlooking Primrose Lake to the northeast. Instrumentation used for surface observations was also situated on this hill. This location was higher than the rest of the terrain (approximately 100 m) and covered by scrub brush and grasses. To the west of the release site was a forested area that consisted of small boreal forest tree cover. The release site was unobstructed. The Pas, Lynn Lake, and Churchill -------------------------------- No site descriptions are available. The verification data measured at the surface were collected at the following sites: BOREAS 1994: Primrose Lake, Alberta (WIQ); Candle Lake, Saskatchewan (WLZ); Thompson Zoo, Manitoba (WTH); Saskatoon Weather Services Office, Saskatchewan (WXE); Key Lake, Saskatchewan (YKJ); The Pas, Manitoba (YQD); Lynn Lake, Manitoba (YYL); Churchill, Manitoba (YYQ). BOREAS 1996: Candle Lake, Saskatchewan (WLZ); Thompson Zoo, Manitoba (WTH); Saskatoon Weather Services Office, Saskatchewan (WXE); The Pas, Manitoba (YQD); Churchill, Manitoba (YYQ). 7.1.2 Spatial Coverage Map Not available. 7.1.3 Spatial Resolution The spatial resolution of the measurements is dependent on flight and atmospheric conditions. 7.1.4 Projection Not applicable. 7.1.5 Grid Description Not applicable. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage The dates during which data were collected varied by station. The data collected in 1993 cover the period of 16-Aug to 20-Aug. The data collected in 1994 cover the period of 09-Apr to 19-Sep with intermittent gaps of a couple weeks. In 1996, the data cover the period of 08-Jul to 22-Oct. 7.2.2 Temporal Coverage Map Not available. 7.2.3 Temporal Resolution Sonde release times (generally) coincided with each other. During BOREAS 1994, the balloon release times were scheduled to follow the times determined by AES. The times of release (GMT or ‘Zulu’) were intended to be at 15 minutes after the hours of 11:00, 13:00, 15:00, 17:00, 19:00, 21:00, and 23:00. The operators were allowed a window of time in which to make the release, spanning from 15 minutes to 25 minutes after the hours specified above. However, these release times were not always the rule. Thompson and Candle Lake released the most sondes (six or seven per day on most days and three per day otherwise), while the other sites were restricted to two - three releases per day. During BOREAS 1996, Candle Lake and Thompson released radiosondes between 12 and 25 minutes after the hours of 11:00, 15:00, 17:00, 19:00, 21:00, and 23:00 (UTC) on fair-weather days and 11:00, 17:00 and 23:00 (UTC) on poor-weather days. Radiosondes at Saskatoon, The Pas, and Churchill were released between 12 and 25 minutes after the hours of 11:00 and 23:00. During an ascent, the nominal time step between data points was: 1993: Candle Lake - 1 sec. Thompson - 1 sec. Saskatoon - approx. 1.3 sec thermodynamics and 1 minute winds. Lynn Lake - approx. 1.3 sec thermodynamics and 1 minute winds. The Pas - no data. Churchill - 10 sec. Key Lake - 1 sec. Primrose Lake - approx. 1.3 sec. 1994: Candle Lake - 5 sec. Thompson - 5 sec. Saskatoon - approx. 1.3 sec thermodynamics and 1 minute winds. Lynn Lake - approx. 1.3 sec thermodynamics and 1 minute winds. The Pas - significant and mandatory level thermodynamics and 1 minute winds. Churchill - 10 sec. Key Lake - 10 sec. Primrose Lake - approx. 1.3 sec. 1996: Candle Lake - 2 sec Thompson - 2 sec Saskatoon - approx. 1.3 sec thermodynamics and 1 minute winds. Lynn Lake - no data The Pas - approx. 1.3 sec thermodynamics and 1 minute winds. Churchill - 10 sec Key Lake - no data Primrose Lake - no data 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (aes_upl1.def). 7.4 Sample Data Record Sample data format shown in the companion data definition file (aes_upl1.def). 8. Data Organization 8.1 Data Granularity Data for each intensive field campaign (by year) are listed in separate files. 8.2 Data Format(s) The data files contain numerical and character fields of varying length separated by commas. The character fields are enclosed with a single apostrophe marks. There are no spaces between the fields. Sample data records are shown in the companion data definition files (aes_upl1.def). 9. Data Manipulations 9.1 Formulae 9.1.1 Derivation Techniques and Algorithms Definition of terms (for below formulae): T = temperature (deg. C) P = pressure (mb) RH = relative humidity (%) MixRat = mixing ratio (g per kg) Ts = saturation (LCL) temperature (K) Ps = saturation (LCL) pressure (mb) Tv = virtual temperature (K) Theta = potential temperature (K) Rd = gas constant = 287.05 (J per kg per Kelvin) G0 = acceleration due to gravity = 9.80665 (m per s sq) ln = natural log exp = exponential TK = air temperature (K) An evaluation of the Vaisala RS80 radiosonde humidity sensor calibration showed a negative bias in humidity measurements. Three sets of humidity measurements were available to evaluate Vaisala RH: 1) M3 (laboratory calibration instrument) RH vs. Vaisala RH in controlled laboratory conditions, 2) routine prelaunch (station) surface temperature and dew point vs. prelaunch Vaisala RH, and 3) sling psychrometer temperature and dew point vs. Vaisala RH in the field. Analysis of all three data sets (with emphasis on laboratory tests) resulted in the following equations for Vaisala RH correction (where h = Vaisala RH), expressed as a fraction of 0 to 1: Bias1 = -0.14286h + 0.10204*(h^2) (utilized when Vaisala RH is < or = 90%) Bias2 = -0.4592 (1 - h) (utilized when Vaisala RH is > 90%) Corrected RH = Vaisala RH - Bias (These equations gave a maximum negative bias of -5% RH at 70% RH, and zero bias at 0% RH and 100% RH.) Geopotential Height: computed step by step as a cumulative sum of height differences between two different altitudes using the hydrostatic equation: Z(2)-Z(1) = (Rd/G0)((Tv(2)+Tv(1))/2)*ln(P(1)/P(2)) where: Virtual Temperature = (T+273.16)*(1.0+Rd/0.62197)/(1.0+Rd)-273.16 Mixing Ratio (Wexler): 622/((16.361/RH)*P*exp(-17.67*T/(T+243.5))-1) Potential Temperature (Theta): (T+273.15)*(1000/P)^(R/cp) where: R/cp = 0.2854*(1-0.28*MixRat/1000) Saturation (LCL) Temperature: 55+(2840/(3.5*ln(Theta)-ln(1000*MixRat/(622+MixRat))-4.805)) Saturation (LCL) Pressure: 1000*(Ts-Theta)^3.4965 Equivalent Potential Temperature (Bolton): Theta*exp(2.67*MixRat/Ts) P, T, RH, U, V, Wdir, Wspd, Range, Azimuth, and Elevation: measured by the upper-air system. 9.2 Data Processing Sequence 9.2.1 Processing Steps The following sections describe how full-resolution data produced by four different upper-air systems (Vaisala, VIZ-W9000, A.I.R., and ADRES) were put into the same format. 9.2.1.1 VAISALA Upper-Air Data Processing Method BINARY | | * Binary file converted to ASCII. | \/ VAISALA (ASCII) | | * Elapsed time converted to hours, minutes, and seconds. | * Geopotential height computed. \/ INTERMEDIATE (ASCII) | | * Potential temperature, equivalent potential temperature, and mixing ratio | computed from temperature and humidity. | \/ | FINAL (ASCII) | | * Commas added to delimit data. | * A column of corrected RH added (see section 9.1.1). All humidity | variables (dew point, potential temp., equivalent potential temp., | and mixing ratio) adjusted based on the RH correction. \/ BORIS Formatted Humidity variables including dew point, potential temperature, equivalent potential temperature, and mixing ratio have been corrected based on the RH correction defined in Section 9.1. The unaltered Vaisala RH and corrected Vaisala RH are both available in the full-resolution files, but only the corrected RH is available in the 5-mb interpolated files. Note that only Vaisala humidity has been revised, which includes flights performed at Candle Lake, Thompson Zoo, Key Lake, and Churchill. 9.2.1.2 VIZ Upper-Air Data Processing Method for Full-Resolution Data FLTDATA.EXE Original flight file Typing "FLTDATA" decompresses flight data files. *.MT2 *.WND *.JNL (binary) (binary) (ASCII) | | | | | | Three files were required for | | | processing: | | | *.MT2: Thermo data (binary) | | | converted to ASCII | | | *.WND: 1 min or 2 min Wind data | | | (binary) converted to ASCII | | | *.JNL: Flight log (ASCII) - no | | | changes | | | THERMO WIND *.JNL (ASCII) (ASCII) (ASCII) | | | ___________ | \/ | * Thermodynamic and wind data files merged. | * Every second line of thermodynamic file (THERMO) kept for processing. | * JNL file used to determine launch and end of flight. \/ COMBINED (ASCII) | | * Thermodynamic data interpolated (linearly) at levels that had | only wind data. | * For Saskatoon (WXE) 1994 flights: surface pressure taken as | the average of 3-10 stable prelaunch sonde pressure measurements. | Also, 2 m added to surface elevation. See below for more info. | \/ FINAL (ASCII) | | * Commas added to delimit data. \/ BORIS Formatted Several files were output by the VIZ W9000 system, but only three were required for data processing. The first was a binary file consisting of thermodynamic data, the second was a binary file containing 1-minute wind information, and the third was a flight information text file. Information from these three files was merged into one file. Surface pressure was measured approximately 12 m above the sonde release site at Saskatoon in 1994. This sometimes resulted in surface pressures that were lower than the first one or two pressures measured by the radiosonde above the ground. To remedy this problem, an average of 3-10 stable radiosonde pressures measured at the release site immediately prior to launch was taken as the surface pressure observation. The surface elevation at Saskatoon (1994) was also found to be 2 m lower than the AES site survey value and was adjusted accordingly. Humidity variables of dew point (Td), potential temperature (Theta), equivalent potential temperature (ThetaE), mixing ratio (MixRat) and relative humidity (RH) have not been corrected. The corrected RH variable (RH_c) was set to missing. 9.2.1.3 A.I.R. System Upper-Air Data Processing Method ASCII | | * Levels with increasing pressures removed (manually). | * No other changes. | \/ ASCII | | * Time converted from seconds to hours, minutes, and seconds. | * Real-time (UTC) variable removed. | \/ INTERMEDIATE (ASCII) | | * Geopotential height recomputed using pressure, temperature, and virtual temperature. | \/ FINAL (ASCII) | | * Commas added to delimit data. | \/ BORIS Formatted 9.2.1.4 ADRES System Upper-Air Data Processing Method ASCII - Significant-level thermodynamics and 1-min wind data. | | * Elapsed time, pressure, temperature, RH, wind direction and speed, and | geopotential height extracted. | \/ COMBINED (ASCII) | | * Time converted from seconds to hours, minutes, and seconds. | \/ INTERMEDIATE (ASCII) | | * Thermodynamic data interpolated (linearly) for wind levels not coinciding | with thermodynamic levels. | * Geopotential height recomputed. | \/ FINAL (ASCII) | | * Commas added to delimit data. | \/ BORIS Formatted The raw significant-level data were transferred to magnetic tape and then copied to 3.5" diskettes. Multiple flights were combined into a few ASCII files. Elapsed time, pressure, temperature, dew point, wind direction, wind speed, and geopotential height were extracted from these ASCII files. Most wind levels (at 1-minute intervals) do not coincide with the significant-level thermodynamic levels. Thermodynamics (including pressure, temperature, and humidity) have therefore been interpolated for wind levels where required. Pressure height was recomputed for all levels using the hydrostatic approximation (see equation in Section 9.1.1). Humidity, pressure, and temperature have been used to compute mixing ratio, potential temperature, and equivalent potential temperature (see formulae in Section 9.1). Humidity variables have not been corrected. 9.2.2 Processing Changes None given. 9.3 Calculations 9.3.1 Special Corrections/Adjustments Corrections/adjustments have been made for: 1) RH (Vaisala, all flights). 2) Elevation and surface pressure (Saskatoon, 1994 flights only). 3) Increasing pressure (A.I.R., Primrose Lake). 4) Some surface observations when required. See Section 9.2.1 for more information. 9.3.2 Calculated Variables zGeoPot, Td, Td_c, Theta, Theta_c, ThetaE, ThetaE_c, MixRat, MixRat_c, RH_c. See Section 9.1.1 for more information on these variables. 9.4 Graphs and Plots None given. 10. Errors 10.1 Sources of Error Surface Observations (see Section 5 for more information): Ordinary Thermometers (housed in Stevenson screens during 1994 at Primrose Lake, Candle Lake and Thompson): Dust or moisture on the instrument could affect the temperature. Human error or a break in the mercury column could also have resulted in an incorrect observation. Wet bulb temperature could have been incorrect if the wick or sleeve had dried out. A dirty or fallen wick/sleeve could have resulted in an error. Also, the observer should have applied the required correction factor for each thermometer and used the psychrometric tables properly to determine the relative humidity. READAC at Key Lake (1994) could have given improper readings if the temperature probe or dew cell was dirty. Moisture inside the dew cell containment could also have resulted in erroneous data. Wind may have been observed improperly by automated sensors if they were defective (i.e., worn bearings). Incorrect observations may have resulted if the dials on the sensor were not properly adjusted. Many problems are associated with estimating wind speed and direction (i.e., at Candle Lake in 1994). Location, improper timing of 2-minute average, gusts, etc., are some of the perceived problems. Sling Psychrometers (Candle Lake and Thompson - 1996, also Saskatoon - 1994 and 1996): Radiation errors may have resulted if the instrument was not shaded properly. If the instrument was not rotated for more than 1 minute, the temperature may not have stabilized. However, if the instrument was rotated too much, the wet bulb sleeve may have dried out, resulting in a humidity measurement that was too high. Other sources of error include improper readings, a dirty sleeve or a break in the mercury column. Pressure from the Barometers at Candle Lake and Thompson (1996): Errors could have resulted from improper readings or incorrect calibration. Wind Direction and Speed (1996): Northerly winds at Candle Lake may have been subject to errors due to obstructions by trees and buildings; however, the anemometer at Thompson was unobstructed in all directions. Surface Observations were not investigated at The Pas and Churchill for BOREAS 1996. Upper Air: Possible sources of error associated with radiosondes include: Improper handling (touching the sensors, dropping the instrument), improper storage (too warm or cold), balloon defects (such as leaks, weak spots), improper balloon inflation (over- or under-inflation), dirty instruments, and radiosonde not equilibrated with the outside atmosphere for the required duration. 10.2 Quality Assessment 10.2.1 Data Validation by Source Graphs and plots have been produced to flag obvious problems in pressure, temperature, humidity, and winds. Any problems were noted. Computed variables (such as potential temperature, mixing ratio, and pressure height) have been scrutinized by comparing different versions of formulae used to compute these variables. Processed variables have been compared with the raw data to ensure that no significant changes have occurred. Any discrepancies have been noted and fixes made. If errors stemmed from the raw data file, the problems were noted and corrections made if necessary. 10.2.2 Confidence Level/Accuracy Judgment The upper-air data, for the most part, are reliable, and few soundings were rejected. Vaisala: Measured RH and temperature with precision; in particular, gave reliable RH measurements below 20% RH. However, the accuracy of wind data was sometimes questionable between the surface and 1-2 km geopotential height. Some Vaisala flights also had high oscillations in wind direction and speed throughout the flight, especially at the most northerly site, Churchill. VIZ W9000: Measured humidity and temperature at high resolution but only produced 1- or 2-minute wind direction and speed. A.I.R.: measured both thermodynamic and wind data at high resolution. Minimal data filtering was performed by these systems well, but few problems were found with both thermodynamic and wind data. ADRES: Due to the nature of these data (significant and mandatory thermodynamic levels), their accuracy relied primarily on the system operator. Few problems were encountered with both thermodynamic and wind data provided by this system. 10.2.3 Measurement Error for Parameters See Section 4.2.1 for instrument precision. 10.2.4 Additional Quality Assessments Not applicable. 10.2.5 Data Verification by Data Center BORIS personnel reviewed the data for consistency and format. In addition, the values from randomly selected flights were plotted and viewed for any seemingly abnormal values. 11. Notes 11.1 Limitations of the Data None given. 11.2 Known Problems with the Data 1) Ekman spirals can be found in Vaisala wind data (usually below 3-km geopotential height). 2) Missing wind data at Thompson Zoo until 6-Jun 15Z due to an equipment failure. 3) Some full resolution flight data near the end of IFC-1 (1994) at Saskatoon were accidentally overwritten. These data have been replaced with significant- level data. 4) Many flights from Candle Lake for the 1996 Fall IFC terminated prematurely. The cause was not determined. 11.3 Usage Guidance 1) Be aware that different systems produce slightly different measurements at different temporal resolutions. 2) The upper-air data have been manipulated by various computer programs, all of which have been scrutinized carefully, but there is still some chance of human error. 3) Be aware that Vaisala RH and all other humidity variables have been corrected based on field and lab tests. The user is recommended to use these corrected data, but the original Vaisala RH is available as well. 4) Be aware that the Vaisala system performed data filtering and gap filling on both wind and thermodynamic data. The other upper-air systems provided less quality control than Vaisala. 11.4 Other Relevant Information None given. 12. Application of the Data Set The data can be used for monitoring the development of the boundary layer and atmospheric movement and condition during the ascents. In addition, the data can be used for comparisons with field studies occuring during respective IFCs. 13. Future Modifications and Plans None given. 14. Software 14.1 Software Description The software used to process BOREAS upper-air data was developed within AES and consisted of a number of different programs written in C++ and QuickBasic. The software was capable of converting the original flight files, which were usually in binary format, to ASCII text. Following this conversion, certain variables were computed and/or interpolated, and the files were then put into a common format. See Sections 9.1 and 9.2 for more information. 14.2 Software Access The software used to process BOREAS data can be accessed through: Alan Barr or Geoff Strong National Hydrology Research Centre Saskatoon, SK 15. Data Access 15.1 Contact Information Ms. Beth Nelson BOREAS Information System NASA GSFC Greenbelt, MD (301) 286-4005 (301) 286-0239 (fax) beth@ltpmail.gsfc.nasa.gov 15.2 Data Center Identification See Section 15.1. 15.3 Procedures for Obtaining Data Users may place requests on line or by telephone, electronic mail, or fax. 15.4 Data Center Status/Plans The level-1 upper-air data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The BOREAS contact at ORNL is: ORNL DAAC User Services Oak Ridge National Laboratory (865) 241-3952 ornldaac@ornl.gov ornl@eos.nasa.gov 16. Output Products and Availability 16.1 Tape Products None. 16.2 Film Products None. 16.3 Other Products Tabular ASCII files. 17. References 17.1 Platform/Sensor/Instrument/Data Processing Documentation Atmospheric Instrumentation Research, Inc. Automatic Radiotheodolite Model AIR-3A-RT (Brochure). Atmospheric Instrumentation Research, Inc. Intellisonde Digital Radiosonde IS-4A Series (Brochure). Atmospheric Instrumentation Research, Inc. RAWIN Upper-Air Sounding Systems (Brochure). Vaisala. 1993. UAD Technical Manual. VIZ Meteorological Instruments. VIZ-BEUKERS LO-CATE MICROSONDE (Brochure). 17.2 Journal Articles and Study Reports Atmospheric Environment Service. 1994. Inspection Reports. BOREAS Experiment Plan, May 1994, Chapters 1-3, Version 3.0 Barr, A. and A. Betts. 1994. Preliminary Summary of BOREAS Upper-Air Soundings Candle Lake and Thompson 1994 Intensive Field Campaigns, Version 0. Beukers, J. M. and M. Friedman,. 1981. A Digital Radiosonde For Automated Observations In the 1980's. Beuker's Laboratories, Inc., St. James, New York. Sellers, P. and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). Sellers, P. and F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). Sellers, P.J., F.G. Hall, R.D. Kelly, A. Black, D. Baldocchi, J. Berry, M. Ryan, K.J. Ranson, P.M. Crill, D.P. Lettenmaier, H. Margolis, J. Cihlar, J. Newcomer, D. Fitzjarrald, P.G. Jarvis, S.T. Gower, D. Halliwell, D. Williams, B. Goodison, D.E. Wickland, and F.E. Guertin. 1997. BOREAS in 1997: Experiment overview, scientific results, and future directions. Journal of Geophysical Research. 102(D24):28731-28770. Sellers, P., F. Hall, and K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94). Sellers, P., F. Hall, and K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere Study: 1996 Operations. NASA BOREAS Report (OPS DOC 96). Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J. Ranson, D. Lettenmaier, and D.E. Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and early results from the 1994 field year. Bulletin of the American Meteorological Society. 76(9):1549-1577. Strong, G.S., A.G. Barr, C.L. Hrynkiw. 1996. Intercomparisons of the Vaisala and Airsonde Sounding Systems During BOREAS. CMOS Bulletin, June 1996. 17.3 Archive/DBMS Usage Documentation None. 18. Glossary of Terms None. 19. List of Acronyms ADRES - Aerological Data REduction System AES - Atmospheric Environment Service AFM-05 - Aricreft Flux and Meteorology Team 5 A.I.R. - Atmospheric Instrumentation Research, Inc. ASCII - American Standard Code for Information Interchange BOREAS - BOReal Ecosystem-Atmosphere Study BORIS - BOREAS Information System CNDL - Candle Lake CHURH - Churchill DAAC - Distributed Active Archive Center EOS - Earth Observing System EOSDIS - EOS Data and Information System GMT - Greenwich Mean Time GSFC - Goddard Space Flight Center IFC - Intensive Field Campaign NAD83 - North American Datum of 1983 NASA - National Aeronautics and Space Administration NSBF - National Scientific Balloon Facility ORNL - Oak Ridge National Laboratory PANP - Prince Albert National Park PRIMR - Primrose Lake RH - Relative Humidity ROM - Read Only Memory SSA - Southern Study Area STOON - Saskatoon THEPAS - The Pas THOMP - Thompson URL - Uniform Resource Locator UTC - Universal Time Code WIQ - Primrose Lake, Alberta WLZ - Candle Lake, Saskatchewan WTH - Thompson Zoo, Saskatchewan WXE - Saskatoon, Saskatchewan YKJ - Key Lake, Saskatchewan YQD - The Pas, Manitoba YYL - Lynn Lake, Manitoba YYQ - Churchill, Manitoba Z - Zulu (i.e., Greenwich Mean Time) 20. Document Information 20.1 Document Revision Date Written: 07-Feb-1997 Revised: 08-May-1998 20.2 Document Review Date(s) BORIS Review: 14-Apr-1998 Science Review: 20.3 Document ID 20.4 Citation Please contact Dr. Alan Barr or Dr. Alan Betts for an appropriate citation. 20.5 Document Curator 20.6 Document URL KEYWORDS UPPER AIR RADIOSONDE AFM05_Upper_Air_L1.doc 05/26/98