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ACOS Version 3.3 release

CO2 data version 3.3 from the Atmospheric CO2 Observations from Space (ACOS) Task are now available

ACOS Version 3.3 release

ACOS version 3.3 global CO2 concentrations for 2010, after advanced quality screening, and bias correction, have been applied

ACOS Version 3.3 release


The Orbiting Carbon Observatory-2 (OCO-2) Team and the Goddard Earth Sciences Data and Information Services Center (GES DISC) are pleased to announce the availability of Atmospheric CO2 Observations from Space (ACOS) Version 3.3 Level 2 data.
The ACOS task is utilizing calibrated Level 1B radiances from the Thermal And Near infrared Sensor for carbon Observations - Fourier Transform Spectrometer (TANSO-FTS) sensor onboard Japan’s Global Greenhouse Observation by Satellite (GOSAT) satellite.
The improvements significantly affecting the retrieval results are listed below:
  • Updated spectroscopy – ABSCO Coefficients V4.1.1;
  • Residual Fitting of First EOF (per band) replaces empirical noise;
  • Reduced aerosol optical depth a priori value to 0.05;
  • Significantly tightened surface pressure constraints, ±1 hectoPascal (roughly equal weight between data & prior);
  • Fit explicitly for fluorescence over land from O2 A band; and
  • Utilize a consistent L1B data version (v150151).
More information on the new ACOS Version 3.3 data is available in the User's Guide:
Data access methods:



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Last updated: Jun 24, 2013 10:45 AM ET