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Direct impacts of waves on tropical cold point tropopause temperature
Author(s) -
Kim JiEun,
Alexander M. Joan
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl062737
Subject(s) - tropopause , cirrus , radiosonde , stratosphere , climatology , environmental science , atmospheric sciences , water vapor , cold wave , potential temperature , lapse rate , quasi biennial oscillation , troposphere , geology , meteorology , physics
Cold point tropopause temperature is a key regulator of cirrus clouds and stratospheric water vapor, which have significant impacts on the Earth's radiation budget and climate. Using tropical radiosonde observations, we show that waves in the tropical tropopause layer lower cold point temperature by 1.6 K on average relative to the seasonal mean. Furthermore, wave activity in the tropical tropopause layer has not been constant over the last 2.5 decades, altering the magnitude of the wave impacts on cold point temperature at a decadal scale. The change in the direct wave impact is partially (~20–30%) responsible for the sudden decrease in cold point temperature and stratospheric water vapor at the end of 2000, which has not been fully explained by changes in the Brewer‐Dobson circulation. We further show that these wave impacts are not well represented in reanalysis data.