The response of a moist zonally symmetric atmosphere to subtropical surface temperature perturbation

✍ Scribed by Xinyu Zheng

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 1014 KB
• Volume: 124
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49712454809

✦ Synopsis

Abstract

A moist zonally symmetric model has been developed in order to inveestigate the response of a moist atmosphere to subtropical surface temperature perturbations. This is an extension of the study by Plumb and Hou (1992) in which they found that the response of a dry atmosphere to a localized subtropical thermal forcing exhibits threshold behaviour. An inviscid steady‐state theory for zonally symmetric moist atmospheres by Emanuel (1995) is presented first. The model calculations confirm the theory. Then the model is used to examine how moisture‐dynamics feedback influences the threshold behaviour, for a given subtropical surface temperature perturbation. The threshold behaviour is not changed by the inclusion of moisture‐dynamics feedback. Finally, calculations are performed for cases with time‐varying surface temperature perturbations, in order to check the extent to which steady‐state theory can be applied. It is found that the theory is applicable to cases with seasonally varying surface temperature perturbations. Finally some implications of this study are discussed.