THE SIMULATION OF INTRASEASONAL ANOMALOUSLY ADVANCING AND RETREATING OF WESTERN PACIFICSUBTROPICAL HIGH

Abstract:

Using IAP-AGCM, a model developed by the institute of atmospheric research, Academia Sinica,controlled numerital expertrients on SST and east Asian circulation have been performed and some conclusions have been reached as follows. The abnomality of subtropical high has a two-month remote lagging response to SSTA of the western tropical Pacific, the South China Sea and the Bay of Bengal. Theabnormality always appears in pair for the western Pacific subtrphal high and the eastern Pacific subtropical high, with the latter beginning earlier than the former. When the SST of the western trophal Pacific, South China Sea and Bay of Bengal anomalously decreases(increases), the subtropical high iskept anomalously more to the south(north),consistently so is the location at which two zonal geopotential waves meet in the subtropical western Pacific. Under the action of the SSTA above and when ablocking pattern over east Asia continent appears, the assembling location of the joinin8 waves for thewestern Pacific is closely related to that of the blocking high, which is especially important to consistentabnormality of the subtropical high.