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| Titel |
Monitoring multi-decadal satellite earth observation of soil moisture using era-land global land water resources dataset |
| VerfasserIn |
Clément Albergel, Wouter Dorigo, Gianpaolo Balsamo, Patricia de Rosnay, Joaquin Munoz-Sabater, Lars Isaksen, Luca Brocca, Richard de Jeu, Wolfgang Wagner |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250089211
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| Publikation (Nr.) |
 EGU/EGU2014-3407.pdf |
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| Zusammenfassung |
| It has been widely recognized that soil moisture is one of the main drivers of the water,
energy and carbon cycles. It is a crucial variable for Numerical Weather Prediction
(NWP) and climate projections because it plays a key role in hydro-meteorological
processes. A good representation of soil moisture conditions can help improving the
forecasting of precipitation, temperature, droughts and floods. For many applications
global or continental scale soil moisture maps are needed. As a consequence, a
signi?cant amount of studies have been conducted to obtain such information. For that
purpose, land surface modeling, remote sensing techniques or a combination of both
through Land Data Assimilation Systems are used. Assessing the quality of these
products is required and for instance, the release of a new -long term- harmonized soil
moisture product (SM-MW hereafter) from remote sensing within the framework of
the European Space Agency’s Water Cycle Multi-mission Observation Strategy
(WACMOS) and Climate Change Initiative (CCI) projects in 2012 (more information at
http://www.esa-soilmoisture-cci.org/) triggered several evaluation activities. The typical
validation approach for model and satellite based data products is to compare them to in
situ observations. However the evaluation of soil moisture products using ground
measurements is not trivial. Even if in the recent years huge efforts were made to make
such observations available in contrasting biomes and climate conditions, long
term and large scale ground measurements networks are still sparse. Additionally,
different networks will present different characteristics (e.g. measurement methods,
installation depths and modes, calibration techniques, measurement interval, and
temporal and spatial coverage). Finally using in situ measurements, the quality of
retrieved soil moisture can be accurately assessed for the locations of the stations. That
is why it is of interest to conceive new validation methods, complementing the
existing soil moisture networks. To do so Land Surface Models (LSM) can be used to
upscale the in situ surface soil moisture observations and complete the evaluation of
satellite derived products, assuming that land surface models, forced with high
quality atmospheric forcing data, adequately capture the soil moisture temporal
dynamic.
In this study, SM-MW is first evaluated using ground measurements of soil moisture over
2007-2010. Along with SM-MW, soil moisture from two revised re-analyses; ERA-Land, an
update of the land surface component of the ERA-Interim reanalysis from the European
Centre for Medium-Range Weather Forecasts (ECMWF) and MERRA-Land, an enhanced
land surface data product based on MERRA reanalysis by the National Aeronautics and
Space Administration (NASA) were evaluated, also. In situ measurements from almost 200
stations from five networks in different countries (USA, Spain, France, China and Australia)
were considered. Then soil moisture from ERA-Land, is used to monitor at a global
scale the consistency of SM-MW over multi-decadal time period (1980-2010). |
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