************************************************************************** README README README README README README README README README ************************************************************************** Atmospheric CARBON MONOXIDE Mixing Ratios NOAA Climate Monitoring and Diagnostics Laboratory Cooperative Air Sampling Network, 1988-1993 Data Contributed by: Paul C. Novelli and Ken A. Masarie National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostics Laboratory, R/E/CG1 325 Broadway Boulder, Colorado, 80303 USA and Cooperative Institute for Research in Environmental Sciences (CIRES) University of Colorado R/E/CG1 Boulder, Colorado 80309-0449 Telephone: (PCN) 303 497-6974 (KAM) 303 497-6270 Electronic Mail: (PCN) pnovelli@cmdl.noaa.gov (KAM) kmasarie@cmdl.noaa.gov *********************************NOTICE************************************ When using the carbon monoxide data in a publication or presentation, please acknowledge the National Oceanic and Atmospheric Administration (NOAA), Climate Monitoring and Diagnostics Laboratory (CMDL), Carbon Cycle Group. The principal investigator would appreciate being notified of any studies involving the data. We would also like to receive preprints of publications to insure that the quality and limitations of the NOAA/CMDL data are accurately represented. Feedback from users may also help us to improve the quality of the data and the location of the sampling sites. Comments regarding the README files and the data files are encouraged. Please send comments to either of the e-mail addresses given above. ************************************WARNING******************************** Users should read and understand all "README" files before using these data, to avoid misinterpretation of the measurements. NOAA/CMDL has attempted to provide the most precise measurements possible. We reserve the right to modify these data files if warranted by calibration issues or data selection routines. If warranted by the type of data set, description of the current selection procedures will be made available. *********************************RETRIEVAL********************************* In additon to the text files found in each of the directories, there are 2 compressed tar files which contain all the files in the corresponding directories, for example: complete.tar.Z contains all the files in the directory 'complete'. If you want to transfer all the files in a directory, it is much more efficient to take the tar file. To transfer these files take the following steps from the ftp prompt. ftp> binary ! set transfer mode to binary ftp> get complete.tar.Z ! transfer the file ftp> bye ! exit ftp $ uncompress complete.tar.Z ! uncompress your local copy $ tar xvf complete.tar ! unpack the file This will place the files in your local directory *************************************************************************** SOURCE AND SCOPE OF THE DATA: CARBON MONOXIDE Individual site files provide CO mixing ratios in parts per billion (ppb) (ppb = parts in 10*9 by mole fraction) based on measurements from the NOAA/CMDL Cooperative Air Sampling Network beginning 1988. Data are provided through June 1993 for stations at which the first sample was collected before July 1991. Below is a list of locations from which samples of air are collected and analyzed for CO. Data not included in this ftp directory may be obtained by contacting the project PI. A listing of all sites in the air sampling network used for CO measurements (as of 9/94) are given in the table below. The table includes the three letter code used to identify each site, the location of the site, latitude and long- itude (in degrees and minutes), the altitude of the sampling location (in meters above mean sea level), the start and end dates for sampling CO, the country, and the cooperating agency. Shipboard sampling occurs every 5 degrees of latitude for two cruise tracks: the Wellington Star (PAW), and California Star (OPC) between North America and Australia or New Zealand, and every 3 degrees latitude between Hong Kong and Singapore for Carla A. Hills and Great Promise (SCS) (data not yet available). Sampling frequencies are approximately weekly for the fixed sites, and average one sample every 3 weeks per latitude zone for PAW and OPC, and about one sample every week per latitude for SCS. The air samples are collected by two general methods: flushing and then pressurizing glass flasks with a pump or opening a stopcock on an evacuated glass flask. (See Lang et al., 1990a,b for details of the sampling network, the equipment and procedures.) During each sampling event a pair of flasks is filled in series. All samples were analyzed for CO at the NOAA/CMDL laboratory in Boulder by gas chromatography with mercuric oxide reduction detection, and all measure- ments are referenced to the CMDL CO scale (Novelli et al., 1991, Novelli et al., 1994). Through most of the period 1988-1991, one flask of a sample pair was analyzed for CO, and when there was suitable pressure remaining in the flask, two aliquots or more were analyzed. We have used the difference in CO mixing ratio between the two aliquots as an indication of the precision of the measurement. Details of the analytical procedures through 1990 are described in Novelli et al., 1992. From the beginning of CO measurements in flask samples (mid 1987) to December 1990 we used a single point calibration sequence as the response characteristics of the CO instrument had been shown to be linear over a range of 0 to 1000 ppb CO (Novelli et al., 1991). In January 1991, we changed the instrument which was used for the analysis of CO in flask air samples. The new instrument exhibited a non-linear response over the range of 0 to 250 ppb CO. Therefore it was necessary to change from a single- point calibration routine to a multiple standard calibration scheme ( a multi- point calibration procedure based upon that used for calibration of standards, as described in Novelli et al., 1994, was used for flask analysis). In October 1991 we began analyzing a single aliquot from both members of a flask pair (rather than 2 or more aliqouts from a single flask). The principle reasons for the change were to simplify flask handling procedures (the CMDL carbon dioxide and methane projects also measure both flasks of the sample pair) and to have flask pair agreement (the difference in mixing ratio between the two flasks collected simultaneously) as an additional diagnostic to use in evaluating the quality of the data. *************************************************************************** TABLE OF SAMPLING SITES IN THE NOAA/CMDL COOPERATIVE AIR SAMPLING NETWORK ALT Alert, N.W.T. 82 27'N 62 31'W 210m 04/92 Canada, Environment Canada/Atmospheric Environment Service ASC Ascension Island, Atlantic Ocean 07 55'S 14 25'W 54m 02/89 U.K., DOD/U.S.A.F. and Pan American World Airways BAL Baltic Sea (Balanga Queen) 55 30'N 16 40'E 7m 08/92 Poland, MIR, Sea Fisheries Institute BME St. David's head, Bermuda 32 22'N 64 39'W 30m 06/91 U.K., Bermuda Biological Station BMW Southhampton, Bermuda 32 16'N 65 53'W 30m 06/91 U.K., Bermuda Biological Station (AEROCE) BRW Barrow, Alaska 71 19'N 156 36'W 11m 07/88 U.S.A., NOAA/Environmental Research Laboratory (CMDL Observatory) CBA Cold Bay, Alaska 55 12'N 162 43'W 25m 04/92 U.S.A., NOAA/National Weather Service CGO Cape Grim, Tasmania 40 41'S 144 41'E 94m 06/91 Australia, CSIRO, Division of Atmospheric Research CHR Christmas Island, Pacific Ocean 01 42'N 157 10'W 3m 12/89 Kiribati, Scripps Institution of Oceanography CMO Cape Meares, Oregon 45 29'N 123 58'W 30m 06/92 U.S.A, Oregon Graduate Institute of Science and Technology GMI Guam, Mariana Islands 13 26'N 144 47'E 2m 10/89 U.S.A., University of Guam/Marine Laboratory GOZ Dewejra Point, Gozo 36 03'N 14 11'E 30m 11/93 Malta, Ministry of Environment HUN Hegyhatsal 46 58'N 16 23'E 240M 03/93 Hungary, Hungarian Meteorological Agency ICE Heimaey, Vestmannaeyjar 63 15'N 20 09'W 100m 10/92 Iceland, Icelandic Meteorological Service ITN Grifton, North Carolina 35 21'N 77 23'W 505m 07/92 U.S.A., WITN Television IZO Tenerife, Canary Islands 28 18'N 16 29'W 2300m 11/91 Spain, Izana Observatory KEY Key Biscayne, Florida 25 40'N 80 12'W 3m 08/91 U.S.A., NOAA/Environmental Research Laboratory (AOML) KUM Cape Kumukahi, Hawaii 19 31'N 154 49'W 3m 07/89 U.S.A., NOAA/Environmental Research Laboratory (CMDL Sampling Site) MBC Mould Bay, N.W.T. 76 15'N 119 21'W 58m 02/92 Canada, Environment Canada/Atmospheric Environment Service MHT Mace Head, Count Galway 53 20'N 9 54'W 25m 06/91 Ireland, University College Atmospheric Research Station (AEROCE) MID Sand Island, Midway 28 13'N 177 22'W 4m 01/92 U.S.A., DOD/U.S.N. MLO Mauna Loa, Hawaii 19 32'N 155 35'W 3397m 07/89 U.S.A., NOAA/Environmental Research Laboratory (CMDL Observatory) NWR Niwot Ridge, Colorado 40 03'N 105 35'W 3475m 12/88 U.S.A., University of Colorado/INSTAAR OPC Pacific Ocean (California Star) 5 degree lat. intervals 10/93 Blue Star Line, Ltd. PAW Pacific Ocean (Wellington Star) 5 degree lat. intervals 05/22/90-07/01/93 Blue Star Line, Ltd. QPC Qinghai Province 36 16'N 100 55'E 3810m 08/90 P.R.C., Chinese Academy of Meteorological Sciences RPB Ragged Pt., St. Phillip's Parish 13 10'N 59 26'W 3m 03/92 Barbados, University of Bristol (P. Simmonds) SCS South China Sea (Carla A. Hills) 3 degree lat. intervals 07/05/91-02/04/93 Chevron SCS South China Sea (Great Promise) 3 degree lat. intervals 11/14/93 Nippon Yosen Kahsha Shipping Company SEY Mahe Island, Seychelles 04 40'S 55 10'E 3m 09/90 Seychelles, New Mexico State University/Physical Science Laboratory SHM Shemya Island, Alaska 52 43'N 174 06'E 40m 06/92 U.S.A., DOD/U.S.A.F. SMO Tutuila, American Samoa 14 15'S 170 34'W 42m 10/88 U.S.A., NOAA/Environmental Research Laboratory (CMDL Observatory) TAP Tae-ahn Peninsula 36 44'N 126 08'E 20m 11/90 Korea, Korea National University of Education UTA Wendover, Utah 39 54'N 113 43'W 1320m 05/93 UUM Ulaan Uul 44 27'N 111 06'E 914m 01/92 Mongolia, Mongolian Hydrometeorological Research Institute **************************************************************************** REFERENCES Lang, P.M., L.P. Steele, R.C. Martin, and K.A. Masarie, 1990a, Atmospheric methane data for the period 1983-1985 from the NOAA/GMCC global cooperative flask sampling network, NOAA Technical Memorandum ERL CMDL-1. Lang, P.M., L.P. Steele, and R.C. Martin, 1990b, Atmospheric methane data for the period 1986-1988 from the NOAA/CMDL global cooperative flask sampling network, NOAA Technical Memorandum ERL CMDL-2. Novelli, P.C., J.E. Elkins, and L.P. Steele, 1991, The development and evaluation of a gravimetric reference scale for measurements of atmospheric carbon monoxide, J. Geophys. Res., 96, 13,109-13,121. Novelli, P.C., L.P. Steele, and P.P. Tans, 1992, Mixing ratios of carbon monoxide in the troposphere, J. Geophys. Res., 97, 20,731-20,750. Novelli, P.C., J.E. Collins, Jr, R.C. Myers, G.W. Sachse, and H.E. Scheel, 1994, Re- evaluation of the NOAA/CMDL carbon monoxide reference scale and comparisons to CO reference gases at NASA-Langley and the Fraunhofer Institute, 99, 12,833- 12,839.