Climatological analysis of cloud and precipitation system associated with extratropical cyclones with a focus on differences between Northern and Southern Hemispheres

2022 Fiscal Year Final Research Report

• Project/Area Number: 17H04856
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Kodama Chihiro 国立研究開発法人海洋研究開発機構, 地球環境部門(環境変動予測研究センター), 副主任研究員 (90598939)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 温帯低気圧 / 雲・降水システム / 高解像度気候シミュレーション

Outline of Final Research Achievements

A series of climate simulation data by global high-resolution non-hydrostatic atmospheric model was analyzed with a focus on extratropical cyclones and fronts. It was shown that the model captures the characteristic features of the precipitation around the extratropical cyclones derived from satellite observation. Also, it was found that the precipitation around the oceanic extratropical cyclones scales with the surface air temperature irrespective of hemispheres and climates, and the rate of precipitation change by the surface air temperature is larger with the intense oceanic extratropical cyclones compared with the averaged ones. An analysis of the front showed that the model captures the distribution of the frequency of occurrence of front and that the frequency is decreased and moved equatorward due to global warming.

Free Research Field

気候科学

Academic Significance and Societal Importance of the Research Achievements

数値モデルによって得られた降水量と地上気温の関係が現実にも存在すると仮定すると、本研究結果は衛星等による高い信頼性を持った全球降水観測を長期間に渡って実施することで、将来気候における降水変化を制約できることを示している。これは、中緯度における降水量の将来気候変化予測の信頼性を高めることにつながる社会的意義の大きな結果である。前線頻度の将来変化については温帯低気圧そのものの将来変化では説明できず、これまでにない予測結果を提示している可能性がある。