Predictability of stratospheric sudden warmings and vortex intensifications, and its influence on the troposphere

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K05286
• 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: Aichi University of Education
• Principal Investigator: Taguchi Masakazu 愛知教育大学, 教育学部, 准教授 (50397527)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 成層圏突然昇温 / 成層圏極渦強化 / 北半球環状モード / 対流圏・成層圏結合 / 季節内・季節予報

Outline of Final Research Achievements

This study investigates characteristics of intraseasonal and seasonal forecasts for the Northern extratropical stratosphere and troposphere during winter using various forecast data sets. In particular, we verify forecasts for major stratospheric sudden warmings using one month forecast data of the Japan Meteorological Agency (JMA). It reveals average predictability picture, as well as differences in forecast errors between warming types (larger errors for vortex split type). We also find significant skill of JMA seasonal winter forecasts only for the stratosphere. These forecasts for the stratospheric polar vortex are strongly related to those for planetary wave activity in the lower stratosphere and troposphere.

Free Research Field

気象学

Academic Significance and Societal Importance of the Research Achievements

数値天気予報モデルの成層圏表現が改善されるにつれて、成層圏極渦の予報に関心が寄せられてきた。成層圏突然昇温等の予報の様子は十分には知られていなかったが、本研究は様々な予報データからその基本的特性を明らかにした。また、成層圏の予報の良し悪しは対流圏起源の惑星波活動のそれと強く関連しており、成層圏に対する対流圏影響の重要性を再確認する。今後さらに、成層圏予報とその後の対流圏予報の関連を調査・理解することで、季節予報の改善に資することが期待できる。