2015 Articles
Seasonality in future tropical lower stratospheric temperature trends
The seasonality of the 21st century trends in tropical lower stratospheric temperature (LST) is examined in simulations by a group of comprehensive chemistry-climate models. In contrast to the past LST trends, there is robust seasonal dependence among ensembles of the same model. Furthermore, most models show strongest cooling around July–September and minimal cooling in February–March, which results in a weakening of the seasonality in tropical LST. Sensitivity simulations with isolated forcing reveal that greenhouse gas increases dominate the future tropical LST trend. This seasonally varying LST trend is linked to changes in the Brewer-Dobson circulation (BDC). The BDC can influence the LST through direct dynamical heating/cooling and indirect radiative effects primarily from ozone changes due to vertical transport. The latter is found to be the main cause for the seasonality of the 21st century LST trend, while it is difficult to separate them in the past.
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Also Published In
- Title
- Journal of Geophysical Research: Atmospheres
- DOI
- https://doi.org/10.1002/2014JD022090
More About This Work
- Academic Units
- Lamont-Doherty Earth Observatory
- Ocean and Climate Physics
- Publisher
- AGU Publications
- Published Here
- October 6, 2015