Publication Date:
2016-06-08
Description:
The vehicles that fly the satellite into a model of the Earth System are observation operators. They provide the link between the quantities simulated by the model and quantities observed from space, either directly (spectral radiance) or indirectly estimated through a retrieval scheme (bio-geophysical variables). By doing so, observation operators enable modellers to properly compare, evaluate and constrain their models with the model-analogue of the satellite observations. This paper provides the formalism and a few examples of how observation operators can be used, in combination with data assimilation techniques, to better ingest satellite products in a manner consistent with the dynamics of the Earth System expressed by models. It describes communalities and potential synergies between assimilation and classical retrievals. The paper explains how the combination of observation operators and their derivatives (linearisations) form powerful research tools. It introduces a technique called automatic differentiation that greatly simplifies both development and maintenance of derivative code.
Print ISSN:
1810-6277
Electronic ISSN:
1810-6285
Topics:
Biology
,
Geosciences
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