Estimation of cumulus cloud-top vertical velocity using geostationary satellite rapid-scan measurements in the tropics and subtropics

2017 Fiscal Year Final Research Report

• Project/Area Number: 16H06720
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: The University of Tokyo
• Principal Investigator: Hamada Atsushi 東京大学, 大気海洋研究所, 特任助教 (30550008)
• Research Collaborator: Takayabu Yukari N. 東京大学, 大気海洋研究所, 教授 ; Higuchi Atsushi 千葉大学, 環境リモートセンシング研究センター, 准教授
• Project Period (FY): 2016-08-26 – 2018-03-31
• Keywords: 鉛直流 / 積雲 / 積乱雲 / 静止衛星

Outline of Final Research Achievements

An algorithm to estimate cloud-top vertical velocity associated with cumulus clouds by using so-called "rapid-scan" measurements from a Japanese geostationary satellite, Himawari-8, is developed. The algorithm is applied to 2-yr observation data, and statistical characteristics of the obtained cloud-top vertical velocity are examined.
In the tropics (15S-15N), the numbers of cumulus samples are higher/lower in the boreal summer/winter. The distribution of terminal cloud-top heights over the oceans is consistent with the so-called "trimodal characteristics" pointed out in the previous studies. The statistical distribution of the cloud-top vertical velocity is generally independent of the season. Over both land and the oceans, the cloud-top vertical velocities are slightly increased around the freezing level (~5km), probably indicating an importance of latent heat release by freezing of cloud droplets in the development of cumulus clouds in the tropics.

Free Research Field

衛星気象学