In:
Geoscientific Model Development, Copernicus GmbH, Vol. 13, No. 3 ( 2020-03-26), p. 1513-1544
Abstract:
Abstract. Global tropospheric ozone reanalyses constructed using different state-of-the-art satellite data assimilation systems, prepared as part of the
Copernicus Atmosphere Monitoring Service (CAMS-iRean and CAMS-Rean) as well as two fully independent reanalyses (TCR-1 and
TCR-2, Tropospheric Chemistry Reanalysis), have been intercompared and evaluated for the past decade. The updated reanalyses (CAMS-Rean and TCR-2) generally show substantially
improved agreements with independent ground and ozone-sonde observations over their predecessor versions (CAMS-iRean and TCR-1) for diurnal,
synoptical, seasonal, and interannual variabilities. For instance, for the Northern Hemisphere (NH) mid-latitudes the tropospheric ozone columns (surface to
300 hPa) from the updated reanalyses show mean biases to within 0.8 DU (Dobson units, 3 % relative to the observed column) with respect to the
ozone-sonde observations. The improved performance can likely be attributed to a mixture of various upgrades, such as revisions in the chemical data
assimilation, including the assimilated measurements, and the forecast model performance. The updated chemical reanalyses agree well with each other
for most cases, which highlights the usefulness of the current chemical reanalyses in a variety of studies. Meanwhile, significant temporal changes
in the reanalysis quality in all the systems can be attributed to discontinuities in the observing systems. To improve the temporal consistency,
a careful assessment of changes in the assimilation configuration, such as a detailed assessment of biases between various retrieval products, is
needed. Our comparison suggests that improving the observational constraints, including the continued development of satellite observing systems,
together with the optimization of model parameterizations such as deposition and chemical reactions, will lead to increasingly consistent long-term
reanalyses in the future.
Type of Medium:
Online Resource
ISSN:
1991-9603
DOI:
10.5194/gmd-13-1513-2020
DOI:
10.5194/gmd-13-1513-2020-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2020
detail.hit.zdb_id:
2456725-5