Elucidating the robust features of the stratosphere by using data from satellite measurements and reanalyses

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K17761
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Kyoto University
• Principal Investigator: Sakazaki Takatoshi 京都大学, 理学研究科, 助教 (70723039)
• Research Collaborator: SHIOTANI Masato ; FUJIWARA Masatomo ; HAMILTON Kevin
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 大気潮汐 / 衛星観測 / 大気再解析 / 成層圏 / 国際共同研究 / S-RIP

Outline of Final Research Achievements

Recently, it is widely recognized that the stratosphere plays an important role on the climate system of the earth. There are several datasets for representing the state of the stratosphere, including data from satellite measurements and reanalysis datasets (the best estimate obtained through the data assimilation technique). However, the difference among these datasets were not reported in a straightforward manner. This study, with a particular focus on diurnal cycle, comprehensively analyzed these data to report such difference quantitatively and elucidate their causes. We found that only a particular mode of the diurnal cycle shows a clear difference between the satellite and reanalysis data. Also, even observations have a non-negligible difference depending on the satellites. The reanalysis data is greately influenced by the assimilation of satellite measurements especially for the middle and upper stratosphere.

Free Research Field

大気科学

Academic Significance and Societal Importance of the Research Achievements

成層圏大気を記述するデータセットは複数の衛星観測データ・大気再解析データが存在する。従来、これらのデータについて系統的な品質評価はなされておらず、「どのデータを使えば良いのか」有益な指標がない状況であった。本研究では、大気の最も基本的な周期変動と言える日周期成分について、複数のデータを用いた網羅的な比較を初めて行い、それぞれのデータセットを使う利点と問題点を明らかにした。この結果は、大気再解析評価に関する国際プロジェクト(S-RIP)の報告書にも掲載されている。