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*** Atmospheric CO2 concentrations from Kyzylcha (ppmv)		***
***							        ***
*** September 1994						***
***						        	***
***  Source: A.M. Brounshtein					***
***         A.A. Shashkov					***
***         N.N. Paramonova					***
***         V.I. Privalov					***
***         Y.A. Starodubtsev					***
***         Main Geophysical Observatory			***
***         Karbyshev Str. 7					***
***         194018 St. Petersburg, Russia			***
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Year  Jan.   Feb.    Mar.   Apr.   May   Jun.   Jul.   Aug.   Sep.   Oct.   Nov.   Dec.  Annual
1989 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 365.51 -99.99
1990 362.20 361.55 363.44 358.15 363.44 350.71 351.22 351.81 350.90 368.47 363.03 363.32 359.02
1991 364.55 367.86 367.01 361.65 366.93 357.25 354.31 352.32 -99.99 -99.99 -99.99 -99.99 -99.99

Atmospheric CO2 concentrations are expressed in parts per million by volume (ppmv). Monthly
averages are calculated from available individual flask measurements for a given month. Annual
averages are based on monthly means. All flask measurements have been adjusted for flask drifting.
The data presented here in ppmv are based on manometric calibrations at the Scripps Institution of
Oceanography (SIO) Central CO2 Laboratory in 1982. This scale is generally referred to as the 
SIO X83 mole fraction scale. E.V. Faber [Main Geophysical Observatory (MGO), St. Petersburg, Russia]
and R.A. Achmedzhanov (Physical Department, Samarkand State University, Samarkand, Republic of
Uzbekistan) contributed to the collection of these measurements. Achmedzhanov supervised the
sampling program at Kyzylcha.
Note: None of the reference gases used by MGO has a CO2 concentration >355 ppmv. As a result, 
a linear extrapolation procedure has been applied to calculate concentration values for air 
samples with concentrations >355 ppmv up to mid-1992. Since August 1992, one of the AES calibration 
gases has been used along with the MGO reference gases to avoid extrapolation. The investigators 
estimate that the extrapolation error for measurements before 1992 does not exceed 0.15 ppmv.