4:15 PM - 4:30 PM
[PEM10-08] Vertical coupling by convections over the Indonesian maritime continent
Keywords:Indonesian maritime continent, cloud convection, gravity waves, diurnal cycle
Theoretically the insolation may excite two categories of diurnal/annual cycles in the atmosphere. One has globally continuous (day-night and summer-winter hemispheric) phase structure as tides and seasonal marches, and the other has local/regional phase structures mainly due to heat contrasts around coastlines as sea-land breeze and monsoon circulations. All of them are interacted with each other (also with equatorially symmetric Hadley circulation) over the IMC. For example, on land, clear sky from sunrise until noon permits maximum heating by insolation and makes rainy season in the hemispheric summer. The parasol effect is suppressed, because clouds are active on land in the evening. A boreal winter monsoon surge intensifies the northern Hadley cell and also diurnal-cycle rainfall in the austral summer rainy season.
The diurnal-cycle local circulation cell is a superposition of upward and downward propagating gravity waves, and the upward component is propagated toward the stratosphere. The tall cloud tops of conditionally unstable troposphere push the tropopause upward and generate gravity waves in the strongly stable stratosphere.