열대 지역 Gross Moist Stability 특징 분석 및 미래 변화
Characteristics of the Gross Moist Stability in the Tropics and Its Future Change
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This study investigates the characteristics of the Gross Moist Stability (GMS) overthe tropics. The GMS summarizes the relationship between large-scale entropy forcing due toradiation and surface fluxes and the response of smaller-scale convection. The GMS is able toexplain both to where moist entropy is advected by the atmospheric circulation and how deepthe moisture flux convergence is in the tropical region. In the deep convective region, positiveGMS appears over the warm pool region due to the strong column-integrated moisture convergenceand the ensuing export of moist entropy to the environment. The vertical advection ofmoist entropy dominates over the horizontal advection in this region. Meanwhile, over the easterntropical ITCZ region, which is characterized by shallow convective area, import of moistentropy by horizontal winds is dominant compared to the vertical moist entropy advection. Future changes in the GMS are also examined using the 22 CMIP5 model simulations. Adecrease in the GMS appears widely across the tropics, but its increase occurs over the western-central equatorial Pacific. It is evident that the increased GMS region corresponds to anincreased region of precipitation, implying that strengthened convection in the future due toincreased entropy forcing exports the enhanced moist energy to stabilize the environment.
Abstract
This study investigates the characteristics of the Gross Moist Stability (GMS) overthe tropics. The GMS summarizes the relationship between large-scale entropy forcing due toradiation and surface fluxes and the response of smaller-scale convection. The GMS is able toexplain both to where moist entropy is advected by the atmospheric circulation and how deepthe moisture flux convergence is in the tropical region. In the deep convective region, positiveGMS appears over the warm pool region due to the strong column-integrated moisture convergenceand the ensuing export of moist entropy to the environment. The vertical advection ofmoist entropy dominates over the horizontal advection in this region. Meanwhile, over the easterntropical ITCZ region, which is characterized by shallow convective area, import of moistentropy by horizontal winds is dominant compared to the vertical moist entropy advection. Future changes in the GMS are also examined using the 22 CMIP5 model simulations. Adecrease in the GMS appears widely across the tropics, but its increase occurs over the western-central equatorial Pacific. It is evident that the increased GMS region corresponds to anincreased region of precipitation, implying that strengthened convection in the future due toincreased entropy forcing exports the enhanced moist energy to stabilize the environment.
참고문헌 (20)
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