Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures
A neural-network-based retrieval method to determine the snow ice water path (SIWP), liquid water path (LWP), and integrated water vapor (IWV) from millimeter and submillimeter brightness temperatures, measured by using airborne radiometers (ISMAR and MARSS), is presented. The neural networks were t...
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ftchalmersuniv:oai:research.chalmers.se:500680 2023-05-15T16:52:56+02:00 Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures Brath, M. Eriksson, Patrick Chawn Harlow, R. Burgdorf, Martin Buehler, S.A. 2018 text https://doi.org/10.5194/amt-11-611-2018 https://research.chalmers.se/en/publication/500680 unknown http://dx.doi.org/10.5194/amt-11-611-2018 https://research.chalmers.se/en/publication/500680 Meteorology and Atmospheric Sciences Water Engineering Oceanography Hydrology Water Resources radiometer brightness temperature climate prediction airborne survey prediction radiative transfer atmospheric modeling measurement method water vapor ice retreat artificial neural network 2018 ftchalmersuniv https://doi.org/10.5194/amt-11-611-2018 2022-12-11T07:05:48Z A neural-network-based retrieval method to determine the snow ice water path (SIWP), liquid water path (LWP), and integrated water vapor (IWV) from millimeter and submillimeter brightness temperatures, measured by using airborne radiometers (ISMAR and MARSS), is presented. The neural networks were trained by using atmospheric profiles from the ICON numerical weather prediction (NWP) model and by radiative transfer simulations using the Atmospheric Radiative Transfer Simulator (ARTS). The basic performance of the retrieval method was analyzed in terms of offset (bias) and the median fractional error (MFE), and the benefit of using submillimeter channels was studied in comparison to pure microwave retrievals. The retrieval is offset-free for SIWP > 0.01kgm -2 , LWP > 0:1kgm -2 , and IWV > 3kgm -2 . The MFE of SIWP decreases from 100% at SIWPD 0.01kgm -2 to 20% at SIWPD 1kgm -2 and the MFE of LWP from 100% at LWP D 0.05kgm -2 to 30% at LWPD 1kgm -2 . The MFE of IWV for IWV > 3kgm -2 is 5 to 8%. The SIWP retrieval strongly benefits from submillimeter channels, which reduce the MFE by a factor of 2, compared to pure microwave retrievals. The IWV and the LWP retrievals also benefit from submillimeter channels, albeit to a lesser degree. The retrieval was applied to ISMAR and MARSS brightness temperatures from FAAM flight B897 on 18 March 2015 of a precipitating frontal system west of the coast of Iceland. Considering the given uncertainties, the retrieval is in reasonable agreement with the SIWP, LWP, and IWV values simulated by the ICON NWP model for that flight. A comparison of the retrieved IWV with IWV from 12 dropsonde measurements shows an offset of 0:5kgm -2 and an RMS difference of 0:8kgm -2 , showing that the retrieval of IWV is highly effective even under cloudy conditions. Other/Unknown Material Iceland Chalmers University of Technology: Chalmers research Atmospheric Measurement Techniques 11 1 611 632 |
institution |
Open Polar |
collection |
Chalmers University of Technology: Chalmers research |
op_collection_id |
ftchalmersuniv |
language |
unknown |
topic |
Meteorology and Atmospheric Sciences Water Engineering Oceanography Hydrology Water Resources radiometer brightness temperature climate prediction airborne survey prediction radiative transfer atmospheric modeling measurement method water vapor ice retreat artificial neural network |
spellingShingle |
Meteorology and Atmospheric Sciences Water Engineering Oceanography Hydrology Water Resources radiometer brightness temperature climate prediction airborne survey prediction radiative transfer atmospheric modeling measurement method water vapor ice retreat artificial neural network Brath, M. Eriksson, Patrick Chawn Harlow, R. Burgdorf, Martin Buehler, S.A. Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures |
topic_facet |
Meteorology and Atmospheric Sciences Water Engineering Oceanography Hydrology Water Resources radiometer brightness temperature climate prediction airborne survey prediction radiative transfer atmospheric modeling measurement method water vapor ice retreat artificial neural network |
description |
A neural-network-based retrieval method to determine the snow ice water path (SIWP), liquid water path (LWP), and integrated water vapor (IWV) from millimeter and submillimeter brightness temperatures, measured by using airborne radiometers (ISMAR and MARSS), is presented. The neural networks were trained by using atmospheric profiles from the ICON numerical weather prediction (NWP) model and by radiative transfer simulations using the Atmospheric Radiative Transfer Simulator (ARTS). The basic performance of the retrieval method was analyzed in terms of offset (bias) and the median fractional error (MFE), and the benefit of using submillimeter channels was studied in comparison to pure microwave retrievals. The retrieval is offset-free for SIWP > 0.01kgm -2 , LWP > 0:1kgm -2 , and IWV > 3kgm -2 . The MFE of SIWP decreases from 100% at SIWPD 0.01kgm -2 to 20% at SIWPD 1kgm -2 and the MFE of LWP from 100% at LWP D 0.05kgm -2 to 30% at LWPD 1kgm -2 . The MFE of IWV for IWV > 3kgm -2 is 5 to 8%. The SIWP retrieval strongly benefits from submillimeter channels, which reduce the MFE by a factor of 2, compared to pure microwave retrievals. The IWV and the LWP retrievals also benefit from submillimeter channels, albeit to a lesser degree. The retrieval was applied to ISMAR and MARSS brightness temperatures from FAAM flight B897 on 18 March 2015 of a precipitating frontal system west of the coast of Iceland. Considering the given uncertainties, the retrieval is in reasonable agreement with the SIWP, LWP, and IWV values simulated by the ICON NWP model for that flight. A comparison of the retrieved IWV with IWV from 12 dropsonde measurements shows an offset of 0:5kgm -2 and an RMS difference of 0:8kgm -2 , showing that the retrieval of IWV is highly effective even under cloudy conditions. |
author |
Brath, M. Eriksson, Patrick Chawn Harlow, R. Burgdorf, Martin Buehler, S.A. |
author_facet |
Brath, M. Eriksson, Patrick Chawn Harlow, R. Burgdorf, Martin Buehler, S.A. |
author_sort |
Brath, M. |
title |
Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures |
title_short |
Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures |
title_full |
Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures |
title_fullStr |
Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures |
title_full_unstemmed |
Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures |
title_sort |
retrieval of an ice water path over the ocean from ismar and marss millimeter and submillimeter brightness temperatures |
publishDate |
2018 |
url |
https://doi.org/10.5194/amt-11-611-2018 https://research.chalmers.se/en/publication/500680 |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
http://dx.doi.org/10.5194/amt-11-611-2018 https://research.chalmers.se/en/publication/500680 |
op_doi |
https://doi.org/10.5194/amt-11-611-2018 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
11 |
container_issue |
1 |
container_start_page |
611 |
op_container_end_page |
632 |
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1766043438884585472 |