TITLE OF THE DATA SET                                                                               
                                                                                                    
Atmospheric CO2 concentrations derived from flask samples collected at U.S.S.R.-operated            
sampling sites.                                                                                     
                                                                                                    
CONTRIBUTORS                                                                                        
                                                                                                    
A. M. Brounshtein                                                                                   
E. V. Faber                                                                                         
A. A. Shashkov                                                                                      
Main Geophysical Observatory                                                                        
Hydrometeorological Service of the U.S.S.R.                                                         
Karbyshev Str 7                                                                                     
194018 St. Petersburg, U.S.S.R.                                                                     
                                                                                                    
                                                                                                    
SOURCE AND SCOPE OF THE DATA                                                                        
                                                                                                    
      Daily atmospheric CO2 concentrations from four U.S.S.R.-operated sampling sites               
(Teriberka Station, Ocean Station Charlie, Bering Island, and Kotelny Island) are provided.  The    
period of record varies by station with the earliest measurements dating back to 1983 and recent    
estimates from early 1991.  These CO2 concentrations are derived from air samples collected in      
1.5-L stainless steel electropolished flasks and later analyzed at the Main Geophysical Observatory 
(St. Petersburg, U.S.S.R.) using a nondispersive infrared gas analyzer.  Measurements not meeting   
wind direction, wind speed, inter-flask agreement, and climate condition criteria have been either  
discarded or flagged.  All measurements have been corrected for drift biases introduced during      
flask storage.  These atmospheric CO2 concentrations are considered indicative of regional          
background air conditions and are directly traceable to World Meteorological Organization           
primary CO2 standards.                                                                              
                                                                                                    
                                                                                                    
DATA FORMAT                                                                                         
                                                                                                    
     Seven files are provided in this subdirectory including this documentation file                  
(NDP033.TXT), four data files containing atmospheric CO2 concentrations from each                   
of the four Soviet stations (KOTELNY.DAT, TERIBERK.DAT, STATIONC.DAT, & BERING.DAT), and            
a FORTRAN IV and SAS retrieval code to read and print the data files (NDP033.FOR &                  
NDP033.SAS).                                                                                        
                                                                                                    
      The data files are each formatted as                                                          
                                                                                                    
        INTEGER SAMPYR, SAMPMO, SAMPDA, DAYYR                                                       
        REAL TIME, CONC, DIFF                                                                       
        CHARACTER FLAG                                                                              
        READ(5,100,END=99) SAMPYR,SAMPMO,SAMPDA,DAYYR,TIME,                                         
        1              CONC,DIFF,FLAG                                                               
   100  FORMAT(5X,3(I2,1X),I3,1X,F8.4,1X,F8.4,1X,F5.1,3X,A1)                                        
                                                                                                    
where                                                                                               
                                                                                                    
     SAMPYR         is the year the flask sample was collected;                                     
                                                                                                    
     SAMPMO         is the month the flask sample was collected;                                    
                                                                                                    
     SAMPDA         is the day of the month the flask sample was collected;                         
                                                                                                    
     DAYYR          is the day of the year the flask sample was collected;                          
                                                                                                    
     TIME           is the year and fraction of year expressed as a single decimal value;           
                                                                                                    
     CONC           is the average CO2 concentration (ppmv).  If DIFF is > 1 ppmv, the lesser of    
                    the flask pair is chosen provided it is within 2 standard deviations of the     
                    plotted smooth curve.  If one of the two samples is lost the same criteria is   
                    applied to the remaining sample concentration value.  If DIFF is <1 ppmv,       
                    the mean of the flask pair is used.                                             
                                                                                                    
     DIFF           is the absolute value of the difference (ppmv) between the flask pair           
                    concentrations;                                                                 
                                                                                                    
     FLAG           is a flag describing the nature of DIFF.  It is assigned a '+' if DIFF is less t
                    or equal to 1, an 'S' if DIFF is greater than 1, and an 'M' if CONC is derived  
                    from a single flask.                                                            
                                                                                                    
      Missing values for the variable DIFF are represented by ~99.9.  All the data (CONC) presented 
here have been adjusted for potential drifts in CO2 concentrations due to lengthy storage in stainle
steel flasks.  These adjustments have been made using the formula:                                  
                                                                                                    
                                     dC = -t(0.23*e - 0.51)                                         
                                                                                                    
where dC is the correction added to the measured concentration value, t is the time in days between 
air sample collection and analysis, and e is the water vapor partial pressure in the air sample     
expressed in millibars.                                                                             
                                                                                                    
Stated in tabular form, the contents include the following.                                         
                                                                                                    
                                                                                                    
                                                                                                    
                          Variable            Variable            Starting            Ending        
Variable                    type                width              column             column        
                                                                                                    
                                                                                                    
SAMPYR                     Numeric                I2                  6                   7         
SAMPMO                     Numeric                I2                  9                  10         
SAMPDA                     Numeric                I2                 12                  13         
DAYYR                      Numeric                I3                 15                  17         
TIME                       Numeric              F8.4                 19                  26         
CONC                       Numeric              F8.4                 28                  35         
DIFF                       Numeric              F5.1                 37                  41         
FLAG                       Character              A1                 45                  45         
                                                                                                    
                                                                                                    
                                                                                                    
REFERENCES                                                                                          
                                                                                                    
Brounshtein, A. M., N. N. Paramonova, A. D. Frolov, and A. A. Shashkov.  1976.  Optical method      
        for determination of CO2 total abundance in a vertical column of the atmosphere.  Trudy     
        GGO 369:5-25.                                                                               
                                                                                                    
Brounshtein, A. M., K. V. Kazakova, E. V. Faber, and A. A. Shashkov.  1988a.  Measurements of       
        the CO2 concentration vertical distribution above the continental regions.  Annals of the MG
        519:34-42.                                                                                  
                                                                                                    
Brounshtein, A. M., E. V. Faber, and A. A. Shashkov.  1988b.  Measurements of the CO2               
        concentration above Leningrad.  Annals of the MGO 519:43-45.                                
                                                                                                    
Brounshtein, A. M., K. V. Kazakova, V. I. Medinez, and E. V. Faber.  1988c.  Measurements of the    
        CO2 concentrations at Ocean Station "C" (North Atlantic).  Annals of the MGO 519:27-43.     
                                                                                                    
Conway, T. J., P. Tans, L. S. Waterman, K. W. Thoning, K. A. Masarie, and R. H. Gammon.  1988.      
        Atmospheric carbon dioxide measurements in the remote global troposphere, 1981-1984.        
        Tellus 40B:81-115.                                                                          
                                                                                                    
Keeling, C. D., R. B. Bacastow, A. F. Carter, S. C. Piper, T. P. Whorf, M. Heimann, W. G. Mook,     
        and H. Roeloffzen.  1989.  A three-dimensional model of atmospheric CO2 transport based     
        on observed winds:  1. Analysis of observational data.  pp. 165-236. In D. H. Peterson (ed.)
        Aspects of Climate Variability in the Pacific and Western Americas. Geophysical Monograph   
        55, American Geophysical Union, Washington, D.C.                                            
                                                                                                    
Komhyr, W. D., R. H. Gammon, T. B. Harris, L. S. Waterman, T. J. Conway, W. R. Taylor, and K.       
        W. Thoning.  1985.  Global atmospheric CO2 distribution and variations from 1968-1982       
        NOAA/GMCC CO2 flask sample data.  Journal of Geophysical Research 90:5567-5596.             
                                                                                                    
Pearman, G. I. and D. J. Beardsmore. 1984.  Atmospheric carbon dioxide measurements in the          
        Australian region: Ten years of aircraft data. Tellus 36B:1-24.                             
                                                                                                    
World Meteorological Organization.  1989.  Provisional Daily Atmospheric Carbon Dioxide             
        Concentrations as measured at BAPMoN sites for the years 1986 and 1987.  WMO/TD-No.         
        306. Geneva, Switzerland.