Keywords:
stratosphere
;
atmosphere
;
climatology
Description / Table of Contents:
SPARC has from its outset been concerned with “Stratospheric Indicators of Climate
Change,” “Stratospheric Processes,” and “Troposphere/Stratosphere Modelling.”
The SPARC project GRIPS (GCM Reality Intercomparison Project) has focused on
comparing troposphere/stratosphere general circulation models with one another,
both in terms of their technical formulations and in their results. Of course, another
aspect of GRIPS is to examine how well model results compare to observations.
Direct model/data comparisons are not so straightforward, however. For instance,
the stratosphere displays a great deal of interannual variability, so that model-data
comparisons necessarily include statistics of both means and variances over
comparable time periods. Additionally, stratospheric data are obtained from
complicated inversions of radiances derived from satellite measurements, from direct
but sparse balloon or rocket measurements, from time continuous but geographically
sparse ground-based remote sensing instruments, and finally from analysis of
stratospheric measurements either by statistical techniques or from data assimilation
methods. The climatologies derived by these different methods do not agree in all
respects. Finally, the entire concept of stratospheric trends means that stratospheric
climatology is itself time varying.
The SPARC Reference Climatology Group was established to update and evaluate
existing middle atmosphere climatologies for use in GRIPS, and in other SPARC
activities. Rather than create a single new “super climatology,” it was decided that a
valuable contribution would be to (1) compile existing climatologies and make them
easily available to the research community, and (2) carefully compare and evaluate
the existing climatologies. The SPARC Data Center was established (in part) as a
response to item (1), and this Report is a response to item (2). Here we present
detailed intercomparisons of climatological wind and temperature data sets that are
currently used in the research community, which are derived from a variety of
meteorological analyses and satellite data sets. Special attention is focused on
tropical winds and temperatures, where large differences exist among separate
analyses. We also include comparisons between the global climatologies and
historical rocketsonde temperature and wind measurements, and also with more
recent lidar temperature data. These comparisons highlight differences and
uncertainties in contemporary middle atmosphere data sets, and allow biases in
particular analyses to be isolated. In addition, a brief atlas of zonal mean wind and
temperature statistics is provided to highlight data availability and as a quick-look
reference. This Report is intended as a companion to the climatological data sets
held in archive at the SPARC Data Center (http://www.sparc.sunysb.edu).
Pages:
Online-Ressource (III, 96 Seiten)
URL:
http://www.sparc-climate.org/publications/sparc-reports/sparc-report-no3/
Language:
English
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