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| Titel |
Enhancing the retrieval methodology for GlobSnow long-term snow water equivalent record |
| VerfasserIn |
K. Luojus, J. Pulliainen, J. Lemmetyinen, M. Takala, T. Smolander, C. Derksen |
| 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 |
250067289
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| Zusammenfassung |
| ABSTRACT
The efforts of the European Space Agency (ESA) GlobSnow project has resulted in a daily hemisphere-scale satellite-based snow water equivalent (SWE) data record spanning more than 30-years. The previous existing daily SWE records have spanned a shorter time period or described the snow conditions on a monthly basis for a similar period. The GlobSnow SWE record, based on methodology by Pulliainen [1] utilizes a data-assimilation based approach for the estimation of SWE which was shown to be superior to the approaches depending solely on satellite-based data [2]. The GlobSnow SWE data record is based on the time-series of measurements by two different space-borne passive radiometers (SMMR and SSM/I) measuring in the microwave region, spanning from 1979 to present day. The utilized sensors provide data at K- and Ka-bands (19 GHz and 37 GHz respectively) at a spatial resolution of approximately 25 km. The GlobSnow SWE data record has been released and is available through the GlobSnow web-pages (www.globsnow.info).
We briefly presents the validation carried out for GlobSnow SWE data with ground-based reference data and the lessons learned from processing a 30-years daily hemispheric record on SWE. Additionally, we present the efforts taking place for the continuous development of the methodology to enhance the satellite-based SWE retrieval and the way this transfers to the reliability of the long-term SWE climate record. The development of SWE retrieval are focused on application of a new HUT multi-layer snow emission model for the retrieval procedure, application of novel techniques to account for lake contamination and mixed pixel effects and efforts carried out to create a homogenized long-term record of weather station-based snow depth observations that are applied within the SWE retrieval scheme.
REFERENCES
[1] Pulliainen, J. Mapping of snow water equivalent and snow depth in boreal and sub-arctic zones by assimilating space-borne microwave radiometer data and ground-based observations. Remote Sensing of Environment. 101: 257-269, 10.1016/j.rse.2006.01.002.
[2] Takala, M., Luojus, K., Pulliainen, J., Derksen, C., Lemmetyinen, J., Kärnä, J.-P, Koskinen, J., Bojkov, B., “Estimating northern hemisphere snow water equivalent for climate research through assimilation of space-borne radiometer data and ground-based measurements”, Remote Sensing of Environment, Vol. 115, Issue 12, 15 December 2011, Pages 3517-3529, ISSN 0034-4257, 10.1016/j.rse.2011.08.014. |
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