HR: 11:20h
AN: A32C-05 INVITED    [Abstracts]
TI: Assimilation of Aura ozone data and comparisons with in situ observations
AU: * Stajner, I
EM: Ivanka.Stajner@nasa.gov
AF: Global Modeling and Assimilation Office, NASA/Goddard, Code 610.1, Greenbelt, MD 20771, United States
AU: Wargan, K
EM: wargan@gmao.gsfc.nasa.gov
AF: Global Modeling and Assimilation Office, NASA/Goddard, Code 610.1, Greenbelt, MD 20771, United States
AU: Pawson, S
EM: pawson@gmao.gsfc.nasa.gov
AF: Global Modeling and Assimilation Office, NASA/Goddard, Code 610.1, Greenbelt, MD 20771, United States
AB: Ozone data from the Ozone Monitoring Instrument (OMI) and the Microwave Limb Sounder (MLS) onboard EOS Aura satellite were assimilated into the Goddard Earth Observing System Version 4 (GEOS-4) ozone assimilation system. Comparison of assimilated ozone with ozone sonde and MOZAIC data indicate an agreement within 10% in the lower stratosphere, where dynamical processes dominate. Assimilation of OMI and MLS data improves tropospheric column estimates in the Atlantic region, but leads to an overestimation in the tropical Pacific in comparison with SHADOZ sondes. Transport and data biases are considered in order to understand these discrepancies. Comparisons of assimilated tropospheric ozone columns with ozone sonde data reveal root-mean-square (RMS) differences of 2.9 to 7.2 DU, which are typically smaller than the model-sonde RMS differences. Four different definitions of the tropopause using temperature lapse rate, potential vorticity (PV) and isentropic surfaces or ozone isosurfaces are compared with respect to their global impact on the estimated tropospheric ozone column. The largest sensitivity in the tropospheric ozone column is found near the subtropical jet, where the ozone or PV determined tropopause typically lies below the lapse rate tropopause.
DE: 0368 Troposphere: constituent transport and chemistry
DE: 3315 Data assimilation
DE: 3360 Remote sensing
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting