An update on global atmospheric ice estimates from satellite observations and reanalyses
<p>This study assesses the global distribution of mean atmospheric ice mass from current state-of-the-art estimates and its variability on daily and seasonal timescales. Ice water path (IWP) retrievals from active and passive satellite platforms are analysed and compared with estimates fro...
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doaj-ea5c10a7a82d4d6baf7d200265aa34592020-11-24T22:22:37ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242018-08-0118112051121910.5194/acp-18-11205-2018An update on global atmospheric ice estimates from satellite observations and reanalysesD. I. Duncan0P. Eriksson1Department of Earth, Space, and Environment, Chalmers University of Technology, 41296, Gothenburg, SwedenDepartment of Earth, Space, and Environment, Chalmers University of Technology, 41296, Gothenburg, Sweden<p>This study assesses the global distribution of mean atmospheric ice mass from current state-of-the-art estimates and its variability on daily and seasonal timescales. Ice water path (IWP) retrievals from active and passive satellite platforms are analysed and compared with estimates from two reanalysis data sets, ERA5 (European Centre for Medium-range Weather Forecasts Reanalysis 5, ECMWF) and MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications 2). Large discrepancies in IWP exist between the satellite data sets themselves, making validation of the model results problematic and indicating that progress towards a consensus on the distribution of atmospheric ice has been limited. Comparing the data sets, zonal means of IWP exhibit similar shapes but differing magnitudes, with large IWP values causing much of the difference in means. Diurnal analysis centred on A-Train overpasses shows similar structures in some regions, but the degree and sign of the variability varies widely; the reanalyses exhibit noisier and higher-amplitude diurnal variability than borne out by the satellite estimates. Spatial structures governed by the atmospheric general circulation are fairly consistent across the data sets, as principal component analysis shows that the patterns of seasonal variability line up well between the data sets but disagree in severity. These results underscore the limitations of the current Earth observing system with respect to atmospheric ice, as the level of consensus between observations is mixed. The large-scale variability of IWP is relatively consistent, whereas disagreements on diurnal variability and global means point to varying microphysical assumptions in retrievals and models alike that seem to underlie the biggest differences.</p>https://www.atmos-chem-phys.net/18/11205/2018/acp-18-11205-2018.pdf |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
D. I. Duncan P. Eriksson |
spellingShingle |
D. I. Duncan P. Eriksson An update on global atmospheric ice estimates from satellite observations and reanalyses Atmospheric Chemistry and Physics |
author_facet |
D. I. Duncan P. Eriksson |
author_sort |
D. I. Duncan |
title |
An update on global atmospheric ice estimates from satellite observations and reanalyses |
title_short |
An update on global atmospheric ice estimates from satellite observations and reanalyses |
title_full |
An update on global atmospheric ice estimates from satellite observations and reanalyses |
title_fullStr |
An update on global atmospheric ice estimates from satellite observations and reanalyses |
title_full_unstemmed |
An update on global atmospheric ice estimates from satellite observations and reanalyses |
title_sort |
update on global atmospheric ice estimates from satellite observations and reanalyses |
publisher |
Copernicus Publications |
series |
Atmospheric Chemistry and Physics |
issn |
1680-7316 1680-7324 |
publishDate |
2018-08-01 |
description |
<p>This study assesses the global distribution of mean atmospheric ice mass from
current state-of-the-art estimates and its variability on daily and seasonal
timescales. Ice water path (IWP) retrievals from active and passive satellite
platforms are analysed and compared
with estimates from two reanalysis data sets, ERA5 (European Centre for
Medium-range Weather Forecasts Reanalysis 5, ECMWF) and MERRA-2 (Modern-Era
Retrospective Analysis for Research and Applications 2). Large discrepancies
in IWP exist between the satellite data sets themselves, making validation of
the model results problematic and indicating that progress towards a
consensus on the distribution of atmospheric ice has been limited. Comparing
the data sets, zonal means of IWP exhibit similar shapes but differing
magnitudes, with large IWP values causing much of the difference in means.
Diurnal analysis centred on A-Train overpasses shows similar structures in
some regions, but the degree and sign of the variability varies widely; the
reanalyses exhibit noisier and higher-amplitude diurnal variability than
borne out by the satellite estimates. Spatial structures governed by the
atmospheric general circulation are fairly consistent across the data sets,
as principal component analysis shows that the patterns of seasonal
variability line up well between the data sets but disagree in severity.
These results underscore the limitations of the current Earth observing
system with respect to atmospheric ice, as the level of consensus between
observations is mixed. The large-scale variability of IWP is relatively
consistent, whereas disagreements on diurnal variability and global means
point to varying microphysical assumptions in retrievals and models alike
that seem to underlie the biggest differences.</p> |
url |
https://www.atmos-chem-phys.net/18/11205/2018/acp-18-11205-2018.pdf |
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