TY  - JOUR
AU  - Tsuchiya, Chikara
AU  - Sato, Kaoru
AU  - Alexander, M. Joan
AU  - Hoffmann, Lars
TI  - Mjo-related intraseasonal variation of gravity waves in the southern hemisphere tropical stratosphere revealed by high-resolution airs observations
JO  - Journal of geophysical research / Atmospheres
VL  - 121
IS  - 13
SN  - 2169-897X
CY  - Hoboken, NJ
PB  - Wiley
M1  - FZJ-2016-03387
SP  - 7641–7651
PY  - 2016
AB  - The intraseasonal variability of gravity waves (GWs) in the austral summer middle stratosphere was examined using dedicated high-resolution temperature retrieval from the Atmospheric Infrared Sounder　data. Composite maps were made of stratospheric GW temperature variances, large-scale zonal winds around the tropopause, and precipitation based on the real-time multivariate Madden-Julian Oscillation (MJO) index. Regional distributions of these quantities are synchronized with the MJO: The GW variances are larger for stronger precipitation, and for more strongly westward wind around the tropopause at a given precipitation. These results suggest that the GWs observed by AIRS in the stratosphere originate from convection. Moreover, it is shown that the zonal wind around the tropopause likely controls the GW propagation into the stratosphere by a critical level filtering mechanism and/or the GW generation by an obstacle source effect. This means that the MJO can modulate the middle atmospheric circulation by regulating the GWs in two ways, namely, generation and propagation.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000380730500009
DO  - DOI:10.1002/2015JD024463
UR  - https://juser.fz-juelich.de/record/810804
ER  -