A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification
Ku-band dual-polarization radar backscatter measurements from the SeaWinds on QuikScat scatterometer and microwave radiometer measurements from the Special Sensor Microwave/Imager (SSM/I) are used to determine periods of surface melt and freeze in the Antarctic ice-shelves. The normalized radar back...
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ftbrighamyoung:oai:scholarsarchive.byu.edu:etd-1173 2023-07-23T04:15:27+02:00 A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification Kunz, Lukas Brad 2004-07-28T07:00:00Z application/pdf https://scholarsarchive.byu.edu/etd/174 https://scholarsarchive.byu.edu/context/etd/article/1173/viewcontent/ETD_CISOPTR_193.pdf unknown BYU ScholarsArchive https://scholarsarchive.byu.edu/etd/174 https://scholarsarchive.byu.edu/context/etd/article/1173/viewcontent/ETD_CISOPTR_193.pdf http://lib.byu.edu/about/copyright/ Theses and Dissertations QuikSCAT SeaWinds ADEOS-2 Antarctica ice-shelves melt detection maximum likelihood backscatter scatterometer calibration diurnal variation Electrical and Computer Engineering text 2004 ftbrighamyoung 2023-07-03T22:14:28Z Ku-band dual-polarization radar backscatter measurements from the SeaWinds on QuikScat scatterometer and microwave radiometer measurements from the Special Sensor Microwave/Imager (SSM/I) are used to determine periods of surface melt and freeze in the Antarctic ice-shelves. The normalized radar backscatter (sigma-0) and backscatter polarization ratio (PR) are used in the maximum likelihood estimation of the ice-state. This method is used to infer the daily ice-surface conditions for 25 selected study points located on the Ronne, Ross, Larsen, Fimbul, Amery, and Shackleton Ice-shelves. The temporal and spatial variations of the radar response are also observed for various neighborhood sizes surrounding each given point during the study period. Criteria for determining the dates of melt-onset and freeze-up for each Austral summer are also presented. Validation of the ice-state and melt-onset date estimates is performed by analyzing corresponding brightness temperature (Tb) measurements from radiometers. QuikScat sigma-0 measurements from 1999 through 2003 are analyzed and it is shown that Ku-band scatterometers are very useful for determining periods of melt in Antarctic ice-sheets and provide high temporal and spatial resolution ice-state estimates. These estimates can be important for long-term studies of the climatic effects of the seasonal and inter-annual melting of the Antarctic ice-sheets. The SeaWinds on QuikScat (QuikScat) and SeaWinds on ADEOS-2 (SeaWinds) scatterometers are identical radar sensors on different spaceborne platforms traversing similar orbits. QuikSCAT and SeaWinds data are used to infer near-surface wind vectors, polar sea-ice extent, polar-ice melt events, among others. In order to verify the relative calibration of these two sensors a simple cross-calibration method is implemented based on land measurements. A first-order polynomial model for the incidence angle dependence of sigma-0 is used to account for biases in the sigma-0 measurements. This model is applied to selected regions of ... Text Antarc* Antarctic Antarctica Ice Shelves Sea ice Brigham Young University (BYU): ScholarsArchive Amery ENVELOPE(-94.063,-94.063,56.565,56.565) Antarctic Austral Shackleton The Antarctic |
institution |
Open Polar |
collection |
Brigham Young University (BYU): ScholarsArchive |
op_collection_id |
ftbrighamyoung |
language |
unknown |
topic |
QuikSCAT SeaWinds ADEOS-2 Antarctica ice-shelves melt detection maximum likelihood backscatter scatterometer calibration diurnal variation Electrical and Computer Engineering |
spellingShingle |
QuikSCAT SeaWinds ADEOS-2 Antarctica ice-shelves melt detection maximum likelihood backscatter scatterometer calibration diurnal variation Electrical and Computer Engineering Kunz, Lukas Brad A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification |
topic_facet |
QuikSCAT SeaWinds ADEOS-2 Antarctica ice-shelves melt detection maximum likelihood backscatter scatterometer calibration diurnal variation Electrical and Computer Engineering |
description |
Ku-band dual-polarization radar backscatter measurements from the SeaWinds on QuikScat scatterometer and microwave radiometer measurements from the Special Sensor Microwave/Imager (SSM/I) are used to determine periods of surface melt and freeze in the Antarctic ice-shelves. The normalized radar backscatter (sigma-0) and backscatter polarization ratio (PR) are used in the maximum likelihood estimation of the ice-state. This method is used to infer the daily ice-surface conditions for 25 selected study points located on the Ronne, Ross, Larsen, Fimbul, Amery, and Shackleton Ice-shelves. The temporal and spatial variations of the radar response are also observed for various neighborhood sizes surrounding each given point during the study period. Criteria for determining the dates of melt-onset and freeze-up for each Austral summer are also presented. Validation of the ice-state and melt-onset date estimates is performed by analyzing corresponding brightness temperature (Tb) measurements from radiometers. QuikScat sigma-0 measurements from 1999 through 2003 are analyzed and it is shown that Ku-band scatterometers are very useful for determining periods of melt in Antarctic ice-sheets and provide high temporal and spatial resolution ice-state estimates. These estimates can be important for long-term studies of the climatic effects of the seasonal and inter-annual melting of the Antarctic ice-sheets. The SeaWinds on QuikScat (QuikScat) and SeaWinds on ADEOS-2 (SeaWinds) scatterometers are identical radar sensors on different spaceborne platforms traversing similar orbits. QuikSCAT and SeaWinds data are used to infer near-surface wind vectors, polar sea-ice extent, polar-ice melt events, among others. In order to verify the relative calibration of these two sensors a simple cross-calibration method is implemented based on land measurements. A first-order polynomial model for the incidence angle dependence of sigma-0 is used to account for biases in the sigma-0 measurements. This model is applied to selected regions of ... |
format |
Text |
author |
Kunz, Lukas Brad |
author_facet |
Kunz, Lukas Brad |
author_sort |
Kunz, Lukas Brad |
title |
A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification |
title_short |
A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification |
title_full |
A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification |
title_fullStr |
A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification |
title_full_unstemmed |
A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification |
title_sort |
new method for melt detection on antarctic ice-shelves and scatterometer calibration verification |
publisher |
BYU ScholarsArchive |
publishDate |
2004 |
url |
https://scholarsarchive.byu.edu/etd/174 https://scholarsarchive.byu.edu/context/etd/article/1173/viewcontent/ETD_CISOPTR_193.pdf |
long_lat |
ENVELOPE(-94.063,-94.063,56.565,56.565) |
geographic |
Amery Antarctic Austral Shackleton The Antarctic |
geographic_facet |
Amery Antarctic Austral Shackleton The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Shelves Sea ice |
genre_facet |
Antarc* Antarctic Antarctica Ice Shelves Sea ice |
op_source |
Theses and Dissertations |
op_relation |
https://scholarsarchive.byu.edu/etd/174 https://scholarsarchive.byu.edu/context/etd/article/1173/viewcontent/ETD_CISOPTR_193.pdf |
op_rights |
http://lib.byu.edu/about/copyright/ |
_version_ |
1772176294910361600 |