Study on the process of CCN production by regarding Kanto plains as a huge chamber

2019 Fiscal Year Final Research Report

• Project/Area Number: 15H02811
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Japan, Meteorological Research Institute
• Principal Investigator: Zaizen Yuji 気象庁気象研究所, 気象予報研究部, 室長 (70354496)
• Co-Investigator(Kenkyū-buntansha): 梶野 瑞王 気象庁気象研究所, 全球大気海洋研究部, 主任研究官 (00447939) ; 北 和之 茨城大学, 理工学研究科(理学野), 教授 (30221914) ; 田尻 拓也 気象庁気象研究所, 気象予報研究部, 主任研究官 (40414510) ; 足立 光司 気象庁気象研究所, 全球大気海洋研究部, 主任研究官 (90630814)
• Project Period (FY): 2015-04-01 – 2020-03-31
• Keywords: エアロゾル / 雲凝結核 / 微粒子 / 有機物 / 電子顕微鏡 / エアロゾルモデル

Outline of Final Research Achievements

For the formation of cloud in the atmosphere, tiny particles are necessary as cloud condensation nuclei (CCN). New particle formation (NPF) is known as an important supplier of CCN. NPF is phenomenon in which very fine particles are formed from gaseous materials such as sulfuric acid vapor. In order to act as CCN, newly formed particles have to grow to 20-50 times in diameter. However, frequency, adequate meteorological conditions for NPF, grow speed, hygroscopicity and its variation as the growth of particles are all not well known.
The Kanto plane in winter is a good location for the observational study of NPF and grow process of newly formed particles. In this study, these processes were researched using various instruments including an electron micrograph and numerical simulations.

Free Research Field

気象学、大気エアロゾル

Academic Significance and Societal Importance of the Research Achievements

天気予報における降水予測や数値モデルでの地球温暖化などの影響予測において、雲の発生頻度、寿命、降水特性、放射特性などは重要なファクターである。雲の性質のうち、かなりの部分は雲粒のサイズ分布で決まり、それはCCNの個数濃度やその吸湿特性分布に依存する。CCNの個数分布を精度よく計算するためには、新粒子生成やそこからの成長過程のよりよい理解が必要であり、この研究はそのために貢献するものである。