| Summary: | 碩士 === 國立中央大學 === 大氣科學學系 === 106 === In this thesis, we identified dominant modes of tropical convection based on the ERA-interim atmospheric data as well as the TRMM precipitation data and examined their roles in transporting moisture and energy in a climatological sense. Based on the technique of EOF decomposition and reconstruction, four major types of convection are identified in the Tropics. The first two types of convection exhibit a two-layer, the first baroclinic structure, with air converging into the convective center at low-levels and diverging aloft. The other two types of convection show a three-layer, the second baroclinic structure, with air converging (or diverging) at mid-levels and diverging (or converging) below and aloft. The roles of different types of convection in transporting atmospheric column moisture and moist static energy (MSE) are also examined. We find that the first two types of convection exhibit distinct tendencies between moisture and MSE transports, i.e., while both types of convection tend to moisten the atmospheric column, they show opposite signs in transporting MSE. A top-heavy convection exports the column MSE, resulting in a stabilization of the atmosphere; while a bottom-heavy convection imports the column MSE, resulting in a destabilization of the atmosphere. In contrast, the last two types of convection show a consistent tendency between moisture and MSE transports. That is, the convection with air diverging at mid-levels (positive mode) imports both the column moisture and MSE, resulting in a rapid destabilization of the atmosphere; while the convection with air converging at mid-levels exports both the column moisture and MSE, resulting in a quick stabilization of the atmosphere.
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