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README  README   README  README  README   README   README   README  README
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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


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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.

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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          

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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.