Retrieval of Surface Emissivity of Sea Ice and Temperature Profiles over Sea Ice from Passive Microwave Radiometers
Polar regions play a key role in the global climate. The information on atmospheric parameters in these regions is sparse. Among the polar surfaces, sea ice varies in extent and physical properties with region and season and so does the surface emissivity. In the present study a method to retrieve t...
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ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/2425 2023-05-15T15:01:56+02:00 Retrieval of Surface Emissivity of Sea Ice and Temperature Profiles over Sea Ice from Passive Microwave Radiometers Bestimmung der Oberflächenemissivität von Meereis und Temperaturprofilenüber Meereis aus Daten passiver Mikrowellenradiometer. Mathew, Nizy Notholt,Justus Kaleschke, Lars 2007-07-19 application/pdf https://media.suub.uni-bremen.de/handle/elib/2425 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000108511 eng eng Universität Bremen FB1 Physik/Elektrotechnik https://media.suub.uni-bremen.de/handle/elib/2425 urn:nbn:de:gbv:46-diss000108511 info:eu-repo/semantics/openAccess sea ice surface emissivity emitting layer temperature temperature profile microwave radiometry 550 550 Earth sciences and geology ddc:550 Dissertation doctoralThesis 2007 ftsubbremen 2022-11-09T07:09:49Z Polar regions play a key role in the global climate. The information on atmospheric parameters in these regions is sparse. Among the polar surfaces, sea ice varies in extent and physical properties with region and season and so does the surface emissivity. In the present study a method to retrieve the emissivity is applied over two selected regions in the Arctic, one covered by first-year ice and the other by multiyear ice and it investigates the application of them in the improvement of temperature profile retrieval ver sea ice. The retrieval of surface emissivity is done by combining simulated brightness temperatures with the satellite measured brightness temperature. In order to determine the surface emissivity of sea ice, the observations of the microwave instruments amsu (Advanced Microwave Sounding Unit) and amsr-e (Advanced Microwave Scanning Radiometer- Earth Observing System) are used. Determination of emissivity requires the knowledge of the temperature of the emitting layer. The penetration depth of microwaves in sea ice varies between millimeters and decimeters depending on the frequency and micro-physical structure. A year-round observation of temperature profiles of sea ice from the Surface Heat Budget of the Arctic Ocean (sheba) campaign at a first-year and a multiyear ice site is used to derive a set of coefficients a and b to linearly relate the lowest level air temperature and the different emitting layer temperatures. The method accounts for the variation of the penetration depthwith frequency, air temperature and sea ice temperature. An algorithm to retrieve temperature profiles from amsu data is modified using the retrieved emissivities and the derived temperature correction factors so that the retrieval accuracy of temperature profiles over sea can be improved. Doctoral or Postdoctoral Thesis Arctic Arctic Ocean Sea ice Surface Heat Budget of the Arctic Ocean Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) Arctic Arctic Ocean |
institution |
Open Polar |
collection |
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
op_collection_id |
ftsubbremen |
language |
English |
topic |
sea ice surface emissivity emitting layer temperature temperature profile microwave radiometry 550 550 Earth sciences and geology ddc:550 |
spellingShingle |
sea ice surface emissivity emitting layer temperature temperature profile microwave radiometry 550 550 Earth sciences and geology ddc:550 Mathew, Nizy Retrieval of Surface Emissivity of Sea Ice and Temperature Profiles over Sea Ice from Passive Microwave Radiometers |
topic_facet |
sea ice surface emissivity emitting layer temperature temperature profile microwave radiometry 550 550 Earth sciences and geology ddc:550 |
description |
Polar regions play a key role in the global climate. The information on atmospheric parameters in these regions is sparse. Among the polar surfaces, sea ice varies in extent and physical properties with region and season and so does the surface emissivity. In the present study a method to retrieve the emissivity is applied over two selected regions in the Arctic, one covered by first-year ice and the other by multiyear ice and it investigates the application of them in the improvement of temperature profile retrieval ver sea ice. The retrieval of surface emissivity is done by combining simulated brightness temperatures with the satellite measured brightness temperature. In order to determine the surface emissivity of sea ice, the observations of the microwave instruments amsu (Advanced Microwave Sounding Unit) and amsr-e (Advanced Microwave Scanning Radiometer- Earth Observing System) are used. Determination of emissivity requires the knowledge of the temperature of the emitting layer. The penetration depth of microwaves in sea ice varies between millimeters and decimeters depending on the frequency and micro-physical structure. A year-round observation of temperature profiles of sea ice from the Surface Heat Budget of the Arctic Ocean (sheba) campaign at a first-year and a multiyear ice site is used to derive a set of coefficients a and b to linearly relate the lowest level air temperature and the different emitting layer temperatures. The method accounts for the variation of the penetration depthwith frequency, air temperature and sea ice temperature. An algorithm to retrieve temperature profiles from amsu data is modified using the retrieved emissivities and the derived temperature correction factors so that the retrieval accuracy of temperature profiles over sea can be improved. |
author2 |
Notholt,Justus Kaleschke, Lars |
format |
Doctoral or Postdoctoral Thesis |
author |
Mathew, Nizy |
author_facet |
Mathew, Nizy |
author_sort |
Mathew, Nizy |
title |
Retrieval of Surface Emissivity of Sea Ice and Temperature Profiles over Sea Ice from Passive Microwave Radiometers |
title_short |
Retrieval of Surface Emissivity of Sea Ice and Temperature Profiles over Sea Ice from Passive Microwave Radiometers |
title_full |
Retrieval of Surface Emissivity of Sea Ice and Temperature Profiles over Sea Ice from Passive Microwave Radiometers |
title_fullStr |
Retrieval of Surface Emissivity of Sea Ice and Temperature Profiles over Sea Ice from Passive Microwave Radiometers |
title_full_unstemmed |
Retrieval of Surface Emissivity of Sea Ice and Temperature Profiles over Sea Ice from Passive Microwave Radiometers |
title_sort |
retrieval of surface emissivity of sea ice and temperature profiles over sea ice from passive microwave radiometers |
publisher |
Universität Bremen |
publishDate |
2007 |
url |
https://media.suub.uni-bremen.de/handle/elib/2425 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000108511 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Sea ice Surface Heat Budget of the Arctic Ocean |
genre_facet |
Arctic Arctic Ocean Sea ice Surface Heat Budget of the Arctic Ocean |
op_relation |
https://media.suub.uni-bremen.de/handle/elib/2425 urn:nbn:de:gbv:46-diss000108511 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766333937123065856 |