Round-robin evaluation of nadir ozone profile retrievals: methodology and application to MetOp-A GOME-2

[摘要] A methodology for the round-robin evaluation and the geophysical validation ofozone profile data retrieved from nadir UV backscatter satellitemeasurements is detailed and discussed, consisting of data set contentstudies, information content studies, co-location studies, and comparisonswith reference measurements. Within the European Space Agency's ClimateChange Initiative on ozone (Ozone_cci project), the proposedround-robin procedure is applied to two nadir ozone profile data setsretrieved at the Royal Netherlands Meteorological Institute (KNMI) and theRutherford Appleton Laboratory (RAL, United Kingdom), using their respectiveOPERA v1.26 and RAL v2.1 optimal estimation algorithms, from MetOp-A GOME-2(i.e. the second generation Global Ozone Monitoring Experiment on the firstMeteorological Operational Satellite) measurements taken in 2008. Theground-based comparisons use ozonesonde and lidar profiles as referencedata, acquired by the Network for the Detection of Atmospheric CompositionChange (NDACC), Southern Hemisphere Additional Ozonesonde programme(SHADOZ), and other stations of the World Meteorological Organisation'sGlobal Atmosphere Watch (WMO GAW). This direct illustration highlightspractical issues that inevitably emerge from discrepancies in e.g. profilerepresentation and vertical smoothing, for which different recipes areinvestigated and discussed. Several approaches for information contentquantification, vertical resolution estimation, and reference profileresampling are compared and applied as well. The paper concludes withcompliance estimates of the two GOME-2 ozone profile data sets with userrequirements from the Global Climate Observing System (GCOS) and fromclimate modellers.

[学科分类] 几何与拓扑