TY - JOUR
T1 - Top-of-Atmosphere Clear-Sky Albedo Estimation over Ocean
T2 - Preliminary Framework for MODIS
AU - Song, Zhen
AU - Liang, Shunlin
AU - Zhou, Hongmin
N1 - Funding Information:
This work was supported in part by the Chinese Grand Research Program on Climate Change and Response under Project 2016YFA0600101, in part by the National Natural Science Foundation of China under Grant 42090012 and Grant 41801242, and in part by the Open Fund of State Key Laboratory of Remote Sensing Science under Grant OFSLRSS202019.
Publisher Copyright:
© 1980-2012 IEEE.
PY - 2022
Y1 - 2022
N2 - Top-of-atmosphere (TOA) albedo is a significant factor of earth energy budget, climate change, and environmental change. As tremendous regional and global changes are happening over ocean, more details are needed to monitor the ocean environment. However, there were still no high-spatial resolution TOA albedo products over ocean. In this study, a new algorithm for clear-sky TOA albedo estimation over ocean was proposed, based on Moderate Resolution Imaging Spectroradiometer (MODIS) data. Instead of building angular distribution models, direct retrieval models between TOA reflectance and TOA albedo were developed based on extensive radiative transfer (RT) simulations, covering thousands of ocean and atmosphere types. Three-component ocean water albedo model was involved to take account for the ocean surface anisotropy at different wind speed, wind direction, and chlorophyll concentration, while Modtran 5 was utilized to simulate different atmospheric conditions. Our results showed good agreement with the Clouds and the Earth's Radiant Energy System (CERES) based on a global comparison on August 4, 2011, with RMSE = 0.015 and bias = 0.002. And our MODIS-based products provide more spatial details due to higher spatial resolution (1 km), which will be a good data source for regional environmental and climatic research and will also enhance the understanding of Earth's radiation budget.
AB - Top-of-atmosphere (TOA) albedo is a significant factor of earth energy budget, climate change, and environmental change. As tremendous regional and global changes are happening over ocean, more details are needed to monitor the ocean environment. However, there were still no high-spatial resolution TOA albedo products over ocean. In this study, a new algorithm for clear-sky TOA albedo estimation over ocean was proposed, based on Moderate Resolution Imaging Spectroradiometer (MODIS) data. Instead of building angular distribution models, direct retrieval models between TOA reflectance and TOA albedo were developed based on extensive radiative transfer (RT) simulations, covering thousands of ocean and atmosphere types. Three-component ocean water albedo model was involved to take account for the ocean surface anisotropy at different wind speed, wind direction, and chlorophyll concentration, while Modtran 5 was utilized to simulate different atmospheric conditions. Our results showed good agreement with the Clouds and the Earth's Radiant Energy System (CERES) based on a global comparison on August 4, 2011, with RMSE = 0.015 and bias = 0.002. And our MODIS-based products provide more spatial details due to higher spatial resolution (1 km), which will be a good data source for regional environmental and climatic research and will also enhance the understanding of Earth's radiation budget.
KW - Climate change
KW - Energy budget
KW - Moderate Resolution Imaging Spectroradiometer (MODIS)
KW - Ocean bidirectional reflectance distribution function (BRDF)
KW - Radiative transfer (RT) simulations
KW - Top-of-atmosphere (TOA) albedo
UR - http://www.scopus.com/inward/record.url?scp=85117138052&partnerID=8YFLogxK
U2 - 10.1109/TGRS.2021.3116620
DO - 10.1109/TGRS.2021.3116620
M3 - Article
AN - SCOPUS:85117138052
SN - 0196-2892
VL - 60
JO - IEEE Transactions on Geoscience and Remote Sensing
JF - IEEE Transactions on Geoscience and Remote Sensing
ER -