Temporal variation of the clock tracers in the tropical tropopause layer and its impact on the stratospheric age of air

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K17760
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Tohoku University (2016-2017); Hokkaido University (2015)
• Principal Investigator: Inai Yoichi 東北大学, 理学研究科, 助教 (50587623)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 成層圏大気の年齢 / 熱帯対流圏界層 / 物質輸送 / 子午面循環

Outline of Final Research Achievements

The atmosphere of the earth has a layered structure including the troposphere and stratosphere. Greenhouse gases and any pollutants are transported to the stratosphere from the troposphere by global meridional circulation. There is an barometer for transport speed in the stratosphere called "age of air," which is estimated from stratospheric concentration of clock tracers. The estimated transport speed is, however, not consistent with that estimated from another method. This study survey the stratospheric transport by using trajectory analysis, and the results suggest that 20% of the inconsistency between the two arise from long-term variation in mixing processes around the tropical tropopause layer.

Free Research Field

大気科学