Applying an ensemble Kalman filter to the assimilation of AERONET observations in a global aerosol transport model

We present a global aerosol assimilation system based on an Ensemble Kalman filter, which we believe leads to a significant improvement in aerosol fields. The ensemble allows realistic, spatially and temporally variable model covariances (unlike other assimilation schemes). As the analyzed variables...

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Egile Nagusiak: Schutgens, N, Miyoshi, T, Takemura, T, Nakajima, T
Formatua: Journal article
Hizkuntza:English
Argitaratua: 2010
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author Schutgens, N
Miyoshi, T
Takemura, T
Nakajima, T
author_facet Schutgens, N
Miyoshi, T
Takemura, T
Nakajima, T
author_sort Schutgens, N
collection OXFORD
description We present a global aerosol assimilation system based on an Ensemble Kalman filter, which we believe leads to a significant improvement in aerosol fields. The ensemble allows realistic, spatially and temporally variable model covariances (unlike other assimilation schemes). As the analyzed variables are mixing ratios (prognostic variables of the aerosol transport model), there is no need for the extra assumptions required by previous assimilation schemes analyzing aerosol optical thickness (AOT). <br/><br/> We describe the implementation of this assimilation system and in particular the construction of the ensemble. This ensemble should represent our estimate of current model uncertainties. Consequently, we construct the ensemble around randomly modified emission scenarios. <br/><br/> The system is tested with AERONET observations of AOT and Angström exponent (AE). Particular care is taken in prescribing the observational errors. The assimilated fields (AOT and AE) are validated through independent AERONET, SKYNET and MODIS Aqua observations. We show that, in general, assimilation of AOT observations leads to improved modelling of global AOT, while assimilation of AE only improves modelling when the AOT is high.
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spelling oxford-uuid:40aa9bfc-b56c-4ad7-ab53-daf71728d9df2022-03-26T14:39:09ZApplying an ensemble Kalman filter to the assimilation of AERONET observations in a global aerosol transport modelJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:40aa9bfc-b56c-4ad7-ab53-daf71728d9dfEnglishSymplectic Elements at Oxford2010Schutgens, NMiyoshi, TTakemura, TNakajima, TWe present a global aerosol assimilation system based on an Ensemble Kalman filter, which we believe leads to a significant improvement in aerosol fields. The ensemble allows realistic, spatially and temporally variable model covariances (unlike other assimilation schemes). As the analyzed variables are mixing ratios (prognostic variables of the aerosol transport model), there is no need for the extra assumptions required by previous assimilation schemes analyzing aerosol optical thickness (AOT). <br/><br/> We describe the implementation of this assimilation system and in particular the construction of the ensemble. This ensemble should represent our estimate of current model uncertainties. Consequently, we construct the ensemble around randomly modified emission scenarios. <br/><br/> The system is tested with AERONET observations of AOT and Angström exponent (AE). Particular care is taken in prescribing the observational errors. The assimilated fields (AOT and AE) are validated through independent AERONET, SKYNET and MODIS Aqua observations. We show that, in general, assimilation of AOT observations leads to improved modelling of global AOT, while assimilation of AE only improves modelling when the AOT is high.
spellingShingle Schutgens, N
Miyoshi, T
Takemura, T
Nakajima, T
Applying an ensemble Kalman filter to the assimilation of AERONET observations in a global aerosol transport model
title Applying an ensemble Kalman filter to the assimilation of AERONET observations in a global aerosol transport model
title_full Applying an ensemble Kalman filter to the assimilation of AERONET observations in a global aerosol transport model
title_fullStr Applying an ensemble Kalman filter to the assimilation of AERONET observations in a global aerosol transport model
title_full_unstemmed Applying an ensemble Kalman filter to the assimilation of AERONET observations in a global aerosol transport model
title_short Applying an ensemble Kalman filter to the assimilation of AERONET observations in a global aerosol transport model
title_sort applying an ensemble kalman filter to the assimilation of aeronet observations in a global aerosol transport model
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