Cloud detection over snow and ice with oxygen A- and B-band observations from the Earth Polychromatic Imaging Camera (EPIC)
Satellite cloud detection over snow and ice has been difficult for passive remote sensing instruments due to the lack of contrast between clouds and cold/bright surfaces; cloud mask algorithms often heavily rely on shortwave infrared (IR) channels over such surfaces. The Earth Polychromatic Imaging...
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ftdoajarticles:oai:doaj.org/article:1e4c1deda747400f8382ef6b3865feb2 2023-05-15T14:03:24+02:00 Cloud detection over snow and ice with oxygen A- and B-band observations from the Earth Polychromatic Imaging Camera (EPIC) Y. Zhou Y. Yang M. Gao P.-W. Zhai 2020-04-01T00:00:00Z https://doi.org/10.5194/amt-13-1575-2020 https://doaj.org/article/1e4c1deda747400f8382ef6b3865feb2 EN eng Copernicus Publications https://www.atmos-meas-tech.net/13/1575/2020/amt-13-1575-2020.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-13-1575-2020 1867-1381 1867-8548 https://doaj.org/article/1e4c1deda747400f8382ef6b3865feb2 Atmospheric Measurement Techniques, Vol 13, Pp 1575-1591 (2020) Environmental engineering TA170-171 Earthwork. Foundations TA715-787 article 2020 ftdoajarticles https://doi.org/10.5194/amt-13-1575-2020 2022-12-31T01:14:41Z Satellite cloud detection over snow and ice has been difficult for passive remote sensing instruments due to the lack of contrast between clouds and cold/bright surfaces; cloud mask algorithms often heavily rely on shortwave infrared (IR) channels over such surfaces. The Earth Polychromatic Imaging Camera (EPIC) on board the Deep Space Climate Observatory (DSCOVR) does not have infrared channels, which makes cloud detection over snow and ice surfaces even more challenging. This study investigates the methodology of applying EPIC's two oxygen absorption band pair ratios in the A band (764, 780 nm) and B band (688, 680 nm) for cloud detection over the snow and ice surfaces. We develop a novel elevation and zenith-angle-dependent threshold scheme based on radiative transfer model simulations that achieves significant improvements over the existing algorithm. When compared against a composite cloud mask based on geosynchronous Earth orbit (GEO) and low Earth orbit (LEO) sensors, the positive detection rate over snow and ice surfaces increased from around 36 % to 65 % while the false detection rate dropped from 50 % to 10 % for observations of January 2016 and 2017. The improvement in July is less substantial due to relatively better performance in the current algorithm. The new algorithm is applicable for all snow and ice surfaces including Antarctic, sea ice, high-latitude snow, and high-altitude glacier regions. This method is less reliable when clouds are optically thin or below 3 km because the sensitivity is low in oxygen band ratios for these cases. Article in Journal/Newspaper Antarc* Antarctic Sea ice Directory of Open Access Journals: DOAJ Articles Antarctic Atmospheric Measurement Techniques 13 3 1575 1591 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
spellingShingle |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 Y. Zhou Y. Yang M. Gao P.-W. Zhai Cloud detection over snow and ice with oxygen A- and B-band observations from the Earth Polychromatic Imaging Camera (EPIC) |
topic_facet |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
description |
Satellite cloud detection over snow and ice has been difficult for passive remote sensing instruments due to the lack of contrast between clouds and cold/bright surfaces; cloud mask algorithms often heavily rely on shortwave infrared (IR) channels over such surfaces. The Earth Polychromatic Imaging Camera (EPIC) on board the Deep Space Climate Observatory (DSCOVR) does not have infrared channels, which makes cloud detection over snow and ice surfaces even more challenging. This study investigates the methodology of applying EPIC's two oxygen absorption band pair ratios in the A band (764, 780 nm) and B band (688, 680 nm) for cloud detection over the snow and ice surfaces. We develop a novel elevation and zenith-angle-dependent threshold scheme based on radiative transfer model simulations that achieves significant improvements over the existing algorithm. When compared against a composite cloud mask based on geosynchronous Earth orbit (GEO) and low Earth orbit (LEO) sensors, the positive detection rate over snow and ice surfaces increased from around 36 % to 65 % while the false detection rate dropped from 50 % to 10 % for observations of January 2016 and 2017. The improvement in July is less substantial due to relatively better performance in the current algorithm. The new algorithm is applicable for all snow and ice surfaces including Antarctic, sea ice, high-latitude snow, and high-altitude glacier regions. This method is less reliable when clouds are optically thin or below 3 km because the sensitivity is low in oxygen band ratios for these cases. |
format |
Article in Journal/Newspaper |
author |
Y. Zhou Y. Yang M. Gao P.-W. Zhai |
author_facet |
Y. Zhou Y. Yang M. Gao P.-W. Zhai |
author_sort |
Y. Zhou |
title |
Cloud detection over snow and ice with oxygen A- and B-band observations from the Earth Polychromatic Imaging Camera (EPIC) |
title_short |
Cloud detection over snow and ice with oxygen A- and B-band observations from the Earth Polychromatic Imaging Camera (EPIC) |
title_full |
Cloud detection over snow and ice with oxygen A- and B-band observations from the Earth Polychromatic Imaging Camera (EPIC) |
title_fullStr |
Cloud detection over snow and ice with oxygen A- and B-band observations from the Earth Polychromatic Imaging Camera (EPIC) |
title_full_unstemmed |
Cloud detection over snow and ice with oxygen A- and B-band observations from the Earth Polychromatic Imaging Camera (EPIC) |
title_sort |
cloud detection over snow and ice with oxygen a- and b-band observations from the earth polychromatic imaging camera (epic) |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/amt-13-1575-2020 https://doaj.org/article/1e4c1deda747400f8382ef6b3865feb2 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Sea ice |
genre_facet |
Antarc* Antarctic Sea ice |
op_source |
Atmospheric Measurement Techniques, Vol 13, Pp 1575-1591 (2020) |
op_relation |
https://www.atmos-meas-tech.net/13/1575/2020/amt-13-1575-2020.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-13-1575-2020 1867-1381 1867-8548 https://doaj.org/article/1e4c1deda747400f8382ef6b3865feb2 |
op_doi |
https://doi.org/10.5194/amt-13-1575-2020 |
container_title |
Atmospheric Measurement Techniques |
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13 |
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3 |
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1575 |
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1591 |
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