Accounting for the effects of sastrugi in the CERES clear-sky Antarctic shortwave angular distribution models
The Cloud and the Earth's Radiant Energy System (CERES) instruments on NASA's Terra, Aqua and Soumi NPP satellites are used to provide a long-term measurement of Earth's energy budget. To accomplish this, the radiances measured by the instruments must be inverted to fluxes by the use...
Published in: | Atmospheric Measurement Techniques |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2015
|
Subjects: | |
Online Access: | https://doi.org/10.5194/amt-8-3163-2015 https://doaj.org/article/51964c8615d347bfb5a0d4050515d4f6 |
id |
ftdoajarticles:oai:doaj.org/article:51964c8615d347bfb5a0d4050515d4f6 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:51964c8615d347bfb5a0d4050515d4f6 2023-05-15T13:44:11+02:00 Accounting for the effects of sastrugi in the CERES clear-sky Antarctic shortwave angular distribution models J. Corbett W. Su 2015-08-01T00:00:00Z https://doi.org/10.5194/amt-8-3163-2015 https://doaj.org/article/51964c8615d347bfb5a0d4050515d4f6 EN eng Copernicus Publications http://www.atmos-meas-tech.net/8/3163/2015/amt-8-3163-2015.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 1867-1381 1867-8548 doi:10.5194/amt-8-3163-2015 https://doaj.org/article/51964c8615d347bfb5a0d4050515d4f6 Atmospheric Measurement Techniques, Vol 8, Iss 8, Pp 3163-3175 (2015) Environmental engineering TA170-171 Earthwork. Foundations TA715-787 article 2015 ftdoajarticles https://doi.org/10.5194/amt-8-3163-2015 2022-12-31T13:22:33Z The Cloud and the Earth's Radiant Energy System (CERES) instruments on NASA's Terra, Aqua and Soumi NPP satellites are used to provide a long-term measurement of Earth's energy budget. To accomplish this, the radiances measured by the instruments must be inverted to fluxes by the use of a scene-type-dependent angular distribution model (ADM). For permanent snow scenes over Antarctica, shortwave (SW) ADMs are created by compositing radiance measurements over the full viewing zenith and azimuth range. However, the presence of small-scale wind blown roughness features called sastrugi cause the BRDF (bidirectional reflectance distribution function) of the snow to vary significantly based upon the solar azimuth angle and location. This can result in monthly regional biases between −12 and 7.5 Wm −2 in the inverted TOA (top-of-atmosphere) SW flux. The bias is assessed by comparing the CERES shortwave fluxes derived from nadir observations with those from all viewing zenith angles, as the sastrugi affect fluxes inverted from the oblique viewing angles more than for the nadir viewing angles. In this paper we further describe the clear-sky Antarctic ADMs from Su et al. (2015). These ADMs account for the sastrugi effect by using measurements from the Multi-Angle Imaging Spectro-Radiometer (MISR) instrument to derive statistical relationships between radiance from different viewing angles. We show here that these ADMs reduce the bias and artifacts in the CERES SW flux caused by sastrugi, both locally and Antarctic-wide. The regional monthly biases from sastrugi are reduced to between −5 and 7 Wm −2 , and the monthly-mean biases over Antarctica are reduced by up to 0.64 Wm −2 , a decrease of 74 %. These improved ADMs are used as part of the Edition 4 CERES SSF (Single Scanner Footprint) data. Article in Journal/Newspaper Antarc* Antarctic Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic Sastrugi ENVELOPE(163.683,163.683,-74.617,-74.617) Atmospheric Measurement Techniques 8 8 3163 3175 |
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 J. Corbett W. Su Accounting for the effects of sastrugi in the CERES clear-sky Antarctic shortwave angular distribution models |
topic_facet |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
description |
The Cloud and the Earth's Radiant Energy System (CERES) instruments on NASA's Terra, Aqua and Soumi NPP satellites are used to provide a long-term measurement of Earth's energy budget. To accomplish this, the radiances measured by the instruments must be inverted to fluxes by the use of a scene-type-dependent angular distribution model (ADM). For permanent snow scenes over Antarctica, shortwave (SW) ADMs are created by compositing radiance measurements over the full viewing zenith and azimuth range. However, the presence of small-scale wind blown roughness features called sastrugi cause the BRDF (bidirectional reflectance distribution function) of the snow to vary significantly based upon the solar azimuth angle and location. This can result in monthly regional biases between −12 and 7.5 Wm −2 in the inverted TOA (top-of-atmosphere) SW flux. The bias is assessed by comparing the CERES shortwave fluxes derived from nadir observations with those from all viewing zenith angles, as the sastrugi affect fluxes inverted from the oblique viewing angles more than for the nadir viewing angles. In this paper we further describe the clear-sky Antarctic ADMs from Su et al. (2015). These ADMs account for the sastrugi effect by using measurements from the Multi-Angle Imaging Spectro-Radiometer (MISR) instrument to derive statistical relationships between radiance from different viewing angles. We show here that these ADMs reduce the bias and artifacts in the CERES SW flux caused by sastrugi, both locally and Antarctic-wide. The regional monthly biases from sastrugi are reduced to between −5 and 7 Wm −2 , and the monthly-mean biases over Antarctica are reduced by up to 0.64 Wm −2 , a decrease of 74 %. These improved ADMs are used as part of the Edition 4 CERES SSF (Single Scanner Footprint) data. |
format |
Article in Journal/Newspaper |
author |
J. Corbett W. Su |
author_facet |
J. Corbett W. Su |
author_sort |
J. Corbett |
title |
Accounting for the effects of sastrugi in the CERES clear-sky Antarctic shortwave angular distribution models |
title_short |
Accounting for the effects of sastrugi in the CERES clear-sky Antarctic shortwave angular distribution models |
title_full |
Accounting for the effects of sastrugi in the CERES clear-sky Antarctic shortwave angular distribution models |
title_fullStr |
Accounting for the effects of sastrugi in the CERES clear-sky Antarctic shortwave angular distribution models |
title_full_unstemmed |
Accounting for the effects of sastrugi in the CERES clear-sky Antarctic shortwave angular distribution models |
title_sort |
accounting for the effects of sastrugi in the ceres clear-sky antarctic shortwave angular distribution models |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/amt-8-3163-2015 https://doaj.org/article/51964c8615d347bfb5a0d4050515d4f6 |
long_lat |
ENVELOPE(163.683,163.683,-74.617,-74.617) |
geographic |
Antarctic Sastrugi |
geographic_facet |
Antarctic Sastrugi |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
Atmospheric Measurement Techniques, Vol 8, Iss 8, Pp 3163-3175 (2015) |
op_relation |
http://www.atmos-meas-tech.net/8/3163/2015/amt-8-3163-2015.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 1867-1381 1867-8548 doi:10.5194/amt-8-3163-2015 https://doaj.org/article/51964c8615d347bfb5a0d4050515d4f6 |
op_doi |
https://doi.org/10.5194/amt-8-3163-2015 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
8 |
container_issue |
8 |
container_start_page |
3163 |
op_container_end_page |
3175 |
_version_ |
1766198416848715776 |