Recently, the research team led by Researcher He Xianqiang and their collaborators published a paper entitled Retrieval of the Aerosol Scale Height over the Ocean Based on Near-infrared Multiangle Polarization Measurements in the top-tier remote sensing journal IEEE Transactions on Geoscience and Remote Sensing.
The first author is Pan Tianfeng, a joint-training doctoral student jointly cultivated by our laboratory and Zhejiang University, and Researcher He Xianqiang acts as the corresponding author. Co-authors include Researcher Bai Yan, Researcher Wang Difeng, Associate Researcher Li Teng and Senior Engineer Gong Fang from our institute, Associate Researcher Liu Jia from Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, as well as Professor Palanisamy Shanmugam from Indian Institute of Technology Madras.
Aerosol Vertical Distribution (AVD) is a key parameter for investigating aerosol radiative effects and conducting air quality evaluation, and it also plays an essential role in atmospheric correction for ocean color remote sensing. In this study, near-infrared multi-angle polarization observation data from the PARASOL polarization satellite were used to retrieve aerosol vertical distribution information.
The research first quantitatively analyzed the impacts of AVD on linear polarization components (PQ, PU) and total radiance component (PI) of satellite-received Stokes vectors, and compared the sensitivity differences of the above components to aerosol height variations. Calculations based on Mie scattering theory confirm that near-infrared polarization measurements are highly correlated with aerosol vertical distribution. Accordingly, a multi-angle polarization remote sensing retrieval algorithm for aerosol scale height was established.
Fig.1 Flowchart of the aerosol scale height retrieval algorithm proposed in this study
Built upon nonlinear optimization and the "black ocean" assumption of polarized water-leaving radiance in the near-infrared band, the constructed model retrieves aerosol vertical distribution information effectively by fitting near-infrared observed linear polarized radiance through nonlinear optimization.
Compared with CALIOP lidar observational data, the root mean square error (RMSE) of retrieval results over three typical oceanic regions (the Pacific Ocean, Atlantic Ocean and Indian Ocean) is less than 1 km. Its accuracy is far higher than the aerosol scale height results retrieved by the GRASP-HP algorithm, with RMSE of 0.967 km for this method versus 2.605 km for GRASP-HP, which verifies the high accuracy of the proposed algorithm.
Fig.2 Comparison between aerosol scale heights retrieved by the proposed algorithm and CALIOP in-situ observed values over partial waters of the Pacific, Atlantic and Indian Oceans
Fig.3 Comparison of global oceanic aerosol scale height retrieval results (60°S–60°N) in 2011 among results from this method, CALIOP observations and GRASP-HP algorithm
In conclusion, this study proves that multi-angle linear polarization data in the near-infrared band can achieve effective retrieval of aerosol vertical distribution structures, offering a new pathway for remote sensing inversion of aerosol vertical profiles.
Paper Citation
Pan, T., He, X.*, Bai, Y., Shanmugam, P., Liu, J., Gong, F., Wang, D., & Li, T. (2024). Retrieval of the Aerosol Scale Height over the Ocean Based on Near-infrared Multiangle Polarization Measurements. IEEE Transactions on Geoscience and Remote Sensing, DOI: 10.1109/TGRS.2024.3495036.
Related Publications
[1] He, X.*, Pan, T., Bai, Y., Shanmugam, P., Wang, D., Li, T., & Gong, F. (2024). Intelligent Atmospheric Correction Algorithm for Polarization Ocean Color Satellite Measurements Over the Open Ocean. IEEE Transactions on Geoscience and Remote Sensing, 62, 1-22.
[2] Pan, T., He, X.*, Bai, Y., Li, T., Gong, F., & Wang, D. (2023). Satellite retrieval of the linear polarization components of the water-leaving radiance in open oceans. Optics Express, 31, 15917-15939.
[3] Pan, T., He, X.*, Bai, Y., Liu, J., Zhu, Q., Gong, F., Li, T., & Jin, X. (2022). Atmospheric diffuse transmittance of the linear polarization component of water-leaving radiation. Optics Express, 30, 27196-27213.
