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Titel |
Cloud and precipitation properties from ground-based remote-sensing instruments in East Antarctica |
VerfasserIn |
I. V. Gorodetskaya, S. Kneifel, M. Maahn, K. Van Tricht, W. Thiery, J. H. Schween, A. Mangold, S. Crewell, N. P. M. van Lipzig |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 9, no. 1 ; Nr. 9, no. 1 (2015-02-11), S.285-304 |
Datensatznummer |
250116751
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Publikation (Nr.) |
copernicus.org/tc-9-285-2015.pdf |
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Zusammenfassung |
A new comprehensive cloud–precipitation–meteorological observatory has been
established at Princess Elisabeth base, located in the escarpment zone of
Dronning Maud Land (DML), East Antarctica. The observatory consists of a set of
ground-based remote-sensing instruments (ceilometer, infrared pyrometer and
vertically profiling precipitation radar) combined with automatic weather
station measurements of near-surface meteorology, radiative fluxes, and snow
height. In this paper, the observatory is presented and the potential for
studying the evolution of clouds and precipitating systems is illustrated by
case studies. It is shown that the synergetic use of the set of instruments
allows for distinguishing ice, liquid-containing clouds and precipitating clouds,
including some information on their vertical extent. In addition, wind-driven
blowing snow events can be distinguished from deeper precipitating systems.
Cloud properties largely affect the surface radiative fluxes, with
liquid-containing clouds dominating the radiative impact. A statistical
analysis of all measurements (in total 14 months mainly during summer–beginning of winter)
indicates that these liquid-containing clouds occur during as much as 20% of
the cloudy periods. The cloud occurrence shows a strong bimodal distribution
with clear-sky conditions 51% of the time and complete overcast conditions
35% of the time. Snowfall occurred during 17% of the cloudy periods with a
predominance of light precipitation and only rare events with snowfall
>1 mm h−1 water equivalent (w.e.). Three of such intense
snowfall events occurred during 2011 contributing to anomalously large annual
surface mass balance (SMB). Large accumulation events
(>10 mm w.e. day−1) during the radar-measurement period of 26
months were always associated with snowfall, but at the same time other
snowfall events did not always lead to accumulation. The multiyear deployment
of a precipitation radar in Antarctica allows for assessing the contribution of
the snowfall to the local SMB and comparing it to the other SMB components.
During 2012, snowfall rate was 110 ± 20 mm w.e. yr−1, from
which surface and drifting snow sublimation removed together 23%. Given the
measured yearly SMB of 52 ± 3 mm w.e., the residual term of
33 ± 21 mm w.e. yr−1 was attributed to the wind-driven snow
erosion. In general, this promising set of robust instrumentation allows for
improved insight into cloud and precipitation processes in Antarctica and can
be easily deployed at other Antarctic stations. |
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