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| Titel |
Cloud optical properties from surface radiation measurements over snow and ice |
| VerfasserIn |
Peter Kuipers Munneke, Carleen Reijmer, Michiel van den Broeke, Rianne Giesen |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250038518
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| Zusammenfassung |
| We present a simple method to extract year-round records of cloud optical thickness from
radiation measurements made over snow and ice surfaces. A ‘longwave-equivalent
cloudiness’, NÉ, obtained from longwave radiation measurements, is combined with the
effective cloud optical thickness, Ï, from shortwave data, to obtain consistent, year-round
information on cloud properties. For a wide variety of Automatic Weather Stations (AWS)
locations (Norwegian glaciers, Greenland ablation area, Antarctic coast and plateau), the
good correlation between daily-mean NÉ and Ï implies that shortwave radiative properties of
clouds can be inferred using longwave radiation even in the absence of solar radiation
itself. An error analysis shows that retrievals of Ï are accurate to about 21% for
hourly values, 11% for daily means, and about 6% for monthly means. As some
applications, we will present clear- and cloudy-sky radiation budgets at several locations,
and demonstrate that it is possible to compute trends of cloud optical thickness in
longer radiation data series. This method can prove useful both for those that wish to
gain more information on cloud climate from their radiation data sets on snow
and ice surfaces (e.g. AWSs), and for those that are looking for validation data of
satellite products of cloud optical thickness in remote polar areas over snow and ice
surfaces. |
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