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Published May 2020 | Published
Journal Article Open

Evaluation of Cloud Microphysical Properties Derived from MODIS and Himawari-8 Using In-Situ Aircraft Measurements over the Southern Ocean

Abstract

Cloud microphysical properties from aircraft measurements during the Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study are used to evaluate the cloud products from the geostationary satellite Himawari‐8 (H‐8) and the polar‐orbiting satellite the Moderate Resolution Imaging Spectroradiometer (MODIS). Compared to the in situ aircraft observations when aircraft flew horizontally near cloud tops, the cloud droplet effective radius (r_e) and number concentration (N_d) from H‐8 (MODIS) are 33% (26%–31%) and 2% (9–13%) larger. Both the H‐8 and MODIS retrievals behave similarly for liquid‐only and mixed‐phase low‐level clouds, indicating the weak sensitivity of the satellite cloud retrieval performance to cloud phase. The r_e and N_d of the cloud profiles from aircraft measurements were also used to compare with the satellite product. It shows that H‐8 r_e and N_d agree better with aircraft measurements when considering only the in situ data acquired in the upper portions (highest 20%) of the clouds. Roughly, the r_e overestimation by H‐8 decreases from 18% to 3% when considering the upper portions of clouds compared to all cloud layer averages, except for one case with drizzles appeared. In addition, the performance of MODIS r_e and N_d is highly dependent on the wavelengths the retrieval method uses. The droplet r_e retrievals using wavelength of 1.6 μm have much larger biases than that using the other two channels. The potential effects of the cloud vertical variation and the photon penetration depth, the cloud heterogeneity, the cloud droplet size spectra, and the drizzle on satellite retrievals have also been discussed.

Additional Information

© 2020 The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. Received 12 FEB 2020; Accepted 25 MAR 2020; Accepted article online 14 APR 2020. This work was supported by the National Natural Science Foundation of China (NSFC) (41925022, 91837204, and 41575143), the Ministry of Science and Technology of China National Key R&D Program on Monitoring, Early Warning and Prevention of Major Natural Disasters (2017YFC1501403), the State Key Laboratory of Earth Surface Processes and Resource Ecology (2017‐ZY‐02), and the Fundamental Research Funds for the Central Universities (2017EYT18). We appreciate the efforts of the entire SOCRATES team in collecting a high‐quality data set. The data that support the findings of this study are available online (https://data.eol.ucar.edu/master_list/?project=SOCRATES). We also highly appreciate the SatCORPS H‐8 cloud product provided by the NASA SatCORPS group through website (https://data.eol.ucar.edu/dataset/552.027).

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Created:
August 22, 2023
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October 23, 2023