| Autor: |
Watt‐Meyer, O., Frierson, D. M. W., Fu, Q. |
| Předmět: |
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| Zdroj: |
Geophysical Research Letters; 8/16/2019, Vol. 46 Issue 15, p9231-9240, 10p |
| Abstrakt: |
The degree of Hadley cell expansion under global warming will have a substantial impact on changing rainfall patterns. Most previous studies have quantified changes in total tropical width, focused on the Southern Hemisphere Hadley cell or considered each hemisphere's response to a multitude of anthropogenic forcings. It is shown here that under exclusive CO2 forcing, climate models predict twice as much Hadley cell expansion in the Southern Hemisphere relative to the Northern Hemisphere. This asymmetry is present in the annual mean expansion and all seasons except boreal autumn. It is robust across models and Hadley cell edge definitions. It is surprising since asymmetries in simulated Hadley cell expansion are typically attributed to stratospheric ozone depletion or aerosol emission. Its primary cause is smaller sensitivity of the Northern Hemisphere Hadley cell to static stability changes. The pattern of sea surface warming and the CO2 direct radiative effect also contribute to the asymmetry. Key Points: There is twice as much Hadley cell expansion in Southern Hemisphere relative to Northern Hemisphere in models under CO2 forcingDegree of asymmetry depends on season but is highly robust across models and Hadley cell definitionsDue to smaller Northern Hemisphere sensitivity to static stability increase, pattern of sea surface warming and direct CO2 radiative effects [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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