A theoretical study on stratospheric cooling due to increase in greenhouse gases

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540471
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Nagoya University
• Principal Investigator: KANZAWA Hiroshi 名古屋大学, 環境学研究科, 教授 (20150047)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 温室効果ガス / 長波放射 / 射出率 / 閾値 / 成層圏の冷却

Outline of Final Research Achievements

We used a simple two-layer atmosphere model constrained by the radiative equilibrium to demonstrate the existence of a threshold value in longwave (LW) emissivity that determines whether increase in LW emissivity, i.e., increase in LW absorptivity, induced by increase in well-mixed greenhouse gasses (WM-GHGs), leads to warming or cooling of the atmosphere, and to investigate the carbon dioxide concentration value corresponding to the threshold value in LW emissivity. We found that the critical emissivity of the stratospheric layer which is required for entering the stratospheric warming stage is 0.258. The threshold value of the carbon dioxide concentration corresponding to the threshold value in LW is also investigated.

Free Research Field

気候科学