Simultaneous retrievals of aerosols and clouds, aerosol indirect effect investigation, and validation of Himawari 8 products

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K05650
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Tohoku University
• Principal Investigator: KHATRI PRADEEP 東北大学, 理学研究科, 講師 (80377986)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 雲 / エアロゾル / 光学的厚さ / 有効半径 / アルゴリズム開発 / 衛星雲プロダクット検証

Outline of Final Research Achievements

An algorithm to retrieve cloud optical thickness (COD) and cloud-particle effective radius (CER) for both water and ice clouds from surface observed spectral zenith radiance by a ground-based sky radiometer was developed. The effects of several factors, including aerosols, on retrieved parameters were evaluated. Except for thin clouds (COD < 15), the retrieval errors are very small for both COD and CER. The proposed algorithm was used to estimate COD and CER of high temporal resolution. Those data were then used to study cloud properties of different sites and seasons of different aerosol backgrounds as well as to validate satellite cloud products.

Free Research Field

大気科学、大気リモートセンシング

Academic Significance and Societal Importance of the Research Achievements

雲は気候システムに重要な役割を果たしています。しかし、その雲の時空間変動が大きく、気候変動に関する政府間パネル（IPCC）第６次報告書等にも明記されているように、その雲は気候変動予測における最大の不確実要素の一つとなっている。このような中、本研究の成果は特に、地上測機による新規な雲観測技術の開発とその地上観測資料を用いた衛星雲プロダクットの精度評価は、雲特性のより正確な理解のため波及効果をもたらすことを期待される。