[L-02] Frontiers of Atmospheric and Hydrosphere Sciences 2: Anthropogenic Phenomena and Their Impact

[L02-01] Polar mesospheric cloud observations by the Japanese geostationary satellites Himawari-8/9

★Invited Papers

*Takuo T. Tsuda¹, Yoshiaki Ando¹, Hidehiko Suzuki², Hiromu Nakagawa³, Takanori Nishiyama⁴, Yoshimasa Tanaka⁴, Yosuke Moriyama¹, Tsubasa Shibuya¹, Masashige Sakai¹, Masakazu Tanaka¹ (1.University of Electro-Communications, 2.Meiji University, 3.Tohoku University, 4.National Institute of Polar Research)

Keywords:Polar Mesospheric Cloud, Noctilucent Cloud, Geostationary Earth Orbit Satellite, Himawari-8/9

Polar mesospheric clouds (PMCs) or noctilucent clouds (NLCs) consist of water-ice particles, which can be produced in summer around the mesopause region, mainly at high latitudes. The first report on PMCs was published in the late 1880's, during which industrial human activity led to a dramatic increase in greenhouse gas emissions, such as CO₂ and CH₄. Then, such greenhouse gas emissions might lead to atmospheric cooling and water vapor increase in the mesospheric heights. Thus, the possibility that the human activity-related effects might promote PMC activity has long been discussed, and such a PMC activity is considered to be the miner's canary of global climate change in the previous publications. On the other hand, a large eruption of Krakatoa occurred during the same period, and the impact of eruptions on PMC activity has also long been discussed. In the proposed scenario, the eruptions might promote PMC activity by cooling the mesosphere and injecting water vapor.

In this talk, we will give an overview on PMC observations by the Japanese GEO meteorological satellites, Himawari-8/9, in which Himawari-8/9 full-disk images are used as limb viewing observations, providing valuable opportunities for PMC observations in the mesospheric heights. Then, our recent research activities related to Himawari-8/9 PMC observations will also be briefly introduced.