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CERES/ARM Validation Experiment (CAVE)
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For validation of CERES/SARB radiation transfer modeling, observed surface radiation
data are collected at over 60 locations around the globe. The following table contains links
details explaning the files.
Summary
CAVE surface observations consist of a host of radiometric, meteorological,
and aerosol observations taken at a number of sites around the globe.
A number of organizations and people have generously made their data available for
dissemination through this web site. That data, generally arrives at 1 minute
temporal resolution and for our purposes is averaged to 15 minute means. The data
is rewritten as binary files, each file contains a header and all available data
for a single site for a single month. These are then released via anonymous ftp along
with programs to read the files. See the links above for lists of files at surface
sites and an on-line plotting tool that prints summary tables of all variables
available at a given site.
There are three types of files in the surface observation data base. The Surface
flux Aerosols & Meteorology (SAM) file contains the surface observations
averaged to 15 minute temporal resolution. The "SYN" or Synoptic files have the same
data averaged to 1-hourly, 3-hourly, 24-hours (daily), and monthly means.
Surface Flux Aerosol & Meteorology (SAM) File Format
The SAM file is a binary (big-endian) file of fixed record length. It consists
of a Header record that contains information regarding the surface site and
a list of variables contained in each file. The remainder of a file
contains one record for each available variable where each record is one month's
worth of data for that variable. Figure 1 below shows this schematically.
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Figure 1. Graphic showing Surface Aerosol Meteorology (SAM) file structure. |
Figure 2. List of commonaly available data in SAM files. |
Figure 2 lists the first 22 variables in every SAM file (identical in each SAM whether the
surface site has recorded the data or not.) Most sites do not record all these varialbes. Some
observe more. If a site has more data of interest, UV data at SURFRAD sites for instance, these
data are include as "Extra" variables in records beyond #22. The number of extra variables in a
file is recorded in the file header. For quickly determining available data at a site go to
the SAM PLOT page where a summary table for all sites in the data
base can be quickly accessed.
Synoptic (SYN) File Format
The synoptic (SYN) file is a binary (big-endian) file of fixed record length.
It consists of a header record that contains information regarding the surface site and a
list of variables contained in each file. The variables in each file are identical to the 15 minute
SAM files described above. The remainder of a file contains three records for each available
variable. The trio of records per variable consists of the means, standard deviations and count.
Packed into each of these three records are the statistics for, one houlry, three hourly, daily and
monthly time periods. Hence the record length is different from that of the SAM file.
Figure 3 below shows this schematically. The third record in each trio contains a simple count of
the number of values going into each average. (eg. 1 to 4; 15 minute values for hourly, 1 to 12;
15 minute averages for 3 hourly, etc . . .) However the monthly mean is calculated from a monthly
mean diurnal cycle for the radiation values so instead of a simple count, the percentage of 15 minute
time periods used in creating the monthly mean diurnal cycle is given instead. For example if three
days are missing from a month, it is still possible to calculate the monthly mean diurnal cycle for
that variable. Given 31 days in the month, the value for "N" in this example would then be:
(744 - 72)
---------- * 100 = 90.3
744
It is left to the user to decide if a variable, which is 90% complete for a month, is suitable
for use in their own application.
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Figure 3. Graphic showing synoptic (SYN) file structure. |
File Naming Conventions
SAM and SYN files can be downloaded via a web tool found here: Data Base.
File names are dependent upon a unique 3-letter identifier for each site.
See Site List for a global map
and listing of all surface sites. Or just continue down to see a list of sites, their 3-Lette identifier and the file name/source.
CAVE File Naming Convention |
Data from DOE Atmospheric Radiation Measurement (ARM) Program |
File Prefix | Surface Site |
arm_C01_ | ARM/SGP Central Facility |
arm_E01_ | Larned, KA |
arm_E02_ | Hillsboro, KA, Boundary Facility B01 |
arm_E03_ | LeRoy, KA |
arm_E04_ | Plevna, KA |
arm_E05_ | Halstead, KA |
arm_E06_ | Towanda, KA |
arm_E07_ | Elk Falls, KA |
arm_E08_ | Coldwater, KA |
arm_E09_ | Ashton, KA |
arm_E10_ | Tyro, KA |
arm_E11_ | Byron, OK |
arm_E12_ | Pawhuska, OK |
arm_E13_ | Lamont, OK |
arm_E15_ | Ringwood, OK |
arm_E16_ | Vici, OK, Boundary Facility B04 |
arm_E18_ | Morris, OK |
arm_E20_ | Meeker, OK |
arm_E22_ | Cordell, OK |
arm_E24_ | Cyril, OK |
arm_MAN_ | Tropical West Pacific, Manus Island |
arm_NAU_ | Tropical West Pacific, Nauru Island |
Data from WCRP Baseline Surface Radiation Network (BSRN) Program |
File Prefix | Surface Site |
bsrn_ASP_ | Alice Springs, Australia |
bsrn_DAA_ | De Aar, South Africa |
bsrn_FLO_ | Florianopolis, Brazil |
bsrn_GVN_ | Georg von Neumayer, Antarctica |
bsrn_LAU_ | Lauder, New Zealand |
bsrn_LIN_ | Lindenberg, Germany |
bsrn_NYA_ | Ny Alesund, Norway |
bsrn_PAY_ | Payerne, Switzerland |
bsrn_SBO_ | Sede Boqer, Israel |
bsrn_SSV_ | Saudi Solar Village |
bsrn_SYO_ | Syowa, Antarctica |
bsrn_TAM_ | Tamanrasset, Algeria |
bsrn_TAT_ | Tateno, Japan |
Data from NOAA Global Monitoring Division (GMD formerly CMDL) Program |
File Prefix | Surface Site |
gmd_BAR_ | Barrow, AK |
gmd_BER_ | Bermuda |
gmd_BOU_ | Boulder, CO (Boulder Tower) |
gmd_KWA_ | Kwajalein Island |
gmd_MLO_ | Mauna Loa, HI |
gmd_SAM_ | Samoa |
gmd_SPL_ | South Pole, Antarctica |
Data from NOAA SURFace Radiation (SURFRAD) Program |
File Prefix | Surface Site |
surfrad_BON_ | Bondville, IL |
surfrad_DRA_ | Desert Rock, NV |
surfrad_FPK_ | Fort Peck, MT |
surfrad_GWN_ | Goodwin Creek, MS |
surfrad_PSU_ | Penn State, PA |
surfrad_TBL_ | Boulder, CO (Table Mountain) |
surfrad_SXF_ | Sioux Falls, SD |
Data from Independent Stations |
File Prefix | Surface Site |
indoex_KAS_ | Kaashidhoo Island, Indian Ocean Experiment (INDOEX) |
larc_COV_ | Chesapeake Lighthouse, Virginia Beach, VA (COVE) |
unva_VAS_ | Valencia Anchor Station, Valencia, Spain |
whoi_PCN_ | Woods Hole PACS Buoy North(10N, -125W) |
whoi_PCS_ | Woods Hole PACS Buoy South(-3S, -125W) |
whoi_NT1_ | Woods Hole NTAS I Buoy |
whoi_NT2_ | Woods Hole NTAS II |
whoi_ST1_ | Woods Hole Stratus I Buoy |
whoi_ST2_ | Woods Hole Stratus II Buoy |
whoi_ST3_ | Woods Hole Stratus III Buoy |
Surface Flux Aerosol & Meteorology (SAM) Statistics Files
Most data coming into our data base arrive as 60 second averages of 1Hz observations. For our purposes
we average these data to 15 minutes (minutes 0 throug 14, 15 through 29, etc...) Often too, data might
be missing. So, statistic files containing the standard deviation of the data over each 15 minute time
period and the number of points that go into each 15 minute average are also maintained and made
available for interested parties. The naming convention is the same execept instead of "avg" they have
"sts" before the version number.
File | File Name |
15 minute average file | surfrad_FPK_200208.avg.v3.0 |
Companions statistics file | surfrad_FPK_200208.sts.v3.0 |
Please contact David Rutan if you would like to
access these files. The format of these files is nearly identical to the average file except
that for each variable there are two records, the standard deviation and count.
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