Horizontal transport of sea spray droplets intensifying tropical cyclones

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K13884
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: University of the Ryukyus
• Principal Investigator: ITO Kosuke 琉球大学, 理学部, 助教 (10634123)
• Research Collaborator: TAKAGAKI Naohisa 兵庫県立大学, 工学部, 助教
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 台風 / 波しぶき / 数値モデル

Outline of Final Research Achievements

Conventional models assume that surface evaporation depends on local physical variables. However, sea spray droplets can remain suspended in the air for several minutes before evaporating under humid conditions in a tropical cyclone (TC). Therefore, spray-mediated evaporation could occur about a few kilometers away from the spray genesis location according to a boundary layer inflow toward the TC center. Because the TC intensity depends on the location in which the evaporation occurs, we conducted a numerical simulation with an idealized atmospheric model that can consider both droplet flight duration and evaporation timescale. As expected, the minimum sea level pressure of a violent TC decreased became strong on the order of 10 hPa in a quasi-steady state and intensification rate became large when the transport of sea spray droplets was incorporated.

Free Research Field

気象学