Index of /ftp/db1011/month
Name Last modified Size Description
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ascmm.co 25-Oct-1994 09:29 1.1K
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bmemm.co 25-Oct-1994 09:29 525
bmwmm.co 25-Oct-1994 09:29 525
brwmm.co 25-Oct-1994 09:29 1.2K
cgomm.co 25-Oct-1994 09:29 525
chrmm.co 25-Oct-1994 09:29 903
gmimm.co 25-Oct-1994 09:29 945
keymm.co 25-Oct-1994 09:29 483
kummm.co 25-Oct-1994 09:29 1.0K
mhtmm.co 25-Oct-1994 09:29 525
mlomm.co 25-Oct-1994 09:29 1.0K
nwrmm.co 25-Oct-1994 09:29 1.1K
qpcmm.co 25-Oct-1994 09:29 735
seymm.co 25-Oct-1994 09:29 672
smomm.co 25-Oct-1994 09:29 1.2K
tapmm.co 25-Oct-1994 09:29 630
***************************************************************************
FILE: pub/co/flask/month/README
UPDATE: October 24, 1994
***************************************************************************
The data files "pub/co/flask/month/xxxmm.co" (where xxx represents the 3
letter station code) are monthly means generated from the data files
"pub/co/flask/complete/xxx.co".
Shipboard data files (these are not yet available in this directory)
"pub/co/flask/month/xxxhllmm.co" (where h represents the hemisphere
(n=northern, s=southern) and ll is the latitude) are generated from the data
files "pub/co/flask/complete/xxxhll.co". The "paw" and "opc" shipboard data
have been combined into a single data set for each latitude, under the station code
"poc" (data not yet available).
A monthly mean co mixing ratio was calculated for each site
by first averaging all values in the complete file with a unique sample
date and time. These data are fit with a curve (see Steele et al., 1992 for
curve fitting techniques), values are pulled from the curve at weekly intervals,
and these values are averaged for each month to give the monthly mean values
in the files. Some sites are excluded from the monthly mean directory,
because sparse data or a short record do not allow a reasonable curve
fit. If there are 3 or more consecutive months without data, then
these months are not included in the monthly mean file. Flagged data are
excluded from the curve fitting process.
The data strings have the form:
xxx yyyy mm ddddd.dd
where the information in each field is:
1. Three-letter code (xxx) indicating the sampling site. See
"/co/flask/README" file for a table of the sampling network sites.
2. Year (yyyy), in Greenwich Mean Time (GMT), the sample was collected.
3. Month (mm, GMT) sample was collected.
4. Monthly mean CO mixing ratio (ddddd.dd) in parts per billion, ppb
(ppb = parts in 10*9 by mole fraction), referenced to the NOAA/CMDL primary
carbon monoxide standard scale.
***************************************************************************
REFERENCES
Lang, P.M., L.P. Steele, and R.C. Martin, 1990, Atmospheric methane data for
the period 1986-1988 from the NOAA/CMDL global cooperative flask sampling
network, NOAA Technical Memorandum ERL CMDL-2.
Lang, P.M., L.P. Steele, L.S. Waterman, R.C. Martin, K.A. Masarie, and
E.J. Dlugokencky, 1992, NOAA/CMDL Atmospheric methane data for the period
1983-1990 from shipboard flask sampling, NOAA Technical Memorandum ERL CMDL-4.
Novelli, P.C., J.W. Elkins, and L.P. Steele, The development and evaluation of a
gravimetric reference scale for measurements of atmopheric carbon monoxide, J.
Geophys. Res., 96, 13,109-13,121, 1991.
Novelli, P.C., L.P. Steele, and P.P. Tans, Mixing ratios of carbon monoxide in
the troposphere, J. Geophys. Res., 97, 20,731-20,750, 1992.
Steele, L.P. and P.M. Lang, 1991, Atmospheric methane concentrations-the
NOAA/CMDL global cooperative flask sampling network, 1983-1988,
ORNL/CDIAC-42, NDP-038.