Assimilated ozone from EOS‐Aura: Evaluation of the tropopause region and tropospheric columns

摘要: [1] Retrievals from the Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) on EOS-Aura were included in Goddard Earth Observing System version 4 (GEOS-4) ozone data assimilation system. The distribution daily to seasonal evolution of stratosphere troposphere during 2005 are investigated. In lower stratosphere, where dynamical processes dominate, comparisons with independent ozonesonde Measurement Water Vapour by Airbus In-Service Aircraft (MOZAIC) indicate mean agreement within 10%. troposphere, OMI MLS provide constraints column, but profile shape results parameterized chemistry resolved transport. Assimilation improves tropospheric column estimates Atlantic region leads an overestimation tropical Pacific underestimation northern high middle latitudes winter spring. Transport biases considered order understand these discrepancies. Comparisons assimilated columns reveal root-mean-square (RMS) differences 2.9–7.2 Dobson units (DU), which smaller than model-sonde RMS 3.2–8.7 DU. Four different definitions tropopause using temperature lapse rate, potential vorticity (PV), isentropic surfaces or isosurfaces compared respect their global impact estimated column. largest sensitivity is found near subtropical jet, ozone- PV-determined typically lies below rate tropopause.