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| Titel |
In-situ ice particle measurements over northern Sweden |
| VerfasserIn |
T. Kuhn, A. J. Heymsfield, S. A. Buehler |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250070597
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| Zusammenfassung |
| Ice clouds play an important role in the energy budget of the atmosphere. They are at high
altitudes, absorb longwave radiation from below and, as they are cold, emit little infrared
radiation. This greenhouse effect warms the Earth-atmosphere system. On the other hand, ice
clouds have a cooling effect by reflecting incoming solar short wave radiation. The net effect
is crucial for the atmosphere, but will depend highly on the cloud’s horizontal extent, vertical
position, ice water content (IWC), and ice particle microphysical properties such as size and
shape. A series of in-situ balloon measurements has been started at Kiruna, Sweden,
which is located at 68°N. Fewer in-situ ice cloud measurements exist at these high
latitudes compared to mid- or tropical latitudes. Also temperatures in the upper
troposphere can be around -60 °C, a temperature range under-represented in available
in-situ data. Ice particles are collected with a balloon-borne replicator launched from
Esrange Space Center (near Kiruna, Sweden). Measurements are complemented
by a radiosonde added to the instrument. The shape and size as well as IWC are
determined from the replicas. The data are analyzed to reveal relationships between IWC
and other measurements such as temperature and volume extinction coefficient.
Such relationships can be used for validation and improvement of satellite retrievals
of IWC from, for example, thin cirrus measurements with satellite-borne lidar. |
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