AIRS near-surface atmospheric CO2 for modeling, transports and assimilation

The Atmospheric Infrared Sounder (AIRS) enables us to retrieve the global distribution of atmospheric CO2 in three layers: Near Surface, Mid-Troposphere and in the Stratosphere. 8-years (2002-2010) of Mid Tropospheric CO2 data sets have been derived and are available to the scientific community for studies of vertical and horizontal transport using Chemistry Transports Models (CTM). In this presentation we discuss the latest results of near surface retrievals, within a layer 2.5 km thick above the surface. The retrieval is based on Gauss' method for finding the local minimum on an N–dimensional surface as described in [Chahine et al., 2005 and 2008, in GRL]. The distribution of tropospheric CO2 is strongly influenced by surface sources and sinks and large scale circulations such as the mid latitude jet streams and by synoptic weather systems, most notably in the summer hemisphere. In addition, the impact of El Nino is observed in the mid-troposphere over the Pacific Ocean. [Jiang et al., 2010, in GRL]

We will focus on the significance of the retrieved CO2 results in the lower troposphere and middle troposphere by establishing quantitative bounds on their random and systematic errors. This is of paramount importance for their use in modeling efforts to understand the sources and sinks and the lifting of CO2 from surface layers into the free troposphere.

The AIRS Mid-Tropospheric CO2 products may be downloaded from the Goddard Earth Science (GES) data and Information Services Center (DISC). Access links to the products are provided on the web page http://airs.jpl.nasa.gov/AIRS_CO2_Data

1 Science Division, Jet Propulsion Laboratory, California Institute of Technology, USA 2 Department of Earth and Atmospheric Sciences, University of Houston, USA 3 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, USA