| Summary: | 碩士 === 國立中央大學 === 大氣科學學系 === 104 === Air pollution issues have been comprehensively studied in recent years. The Southeast Asian biomass burning events, particularly in Indochina Peninsula, provide a favorable environment for probing the aerosol-cloud-radiation interactions. Meanwhile, there is an interesting weather phenomenon showed up. A vast ubiquitous low-level stratocumulus exist over the Southeast Asia during the spring time. Based upon the satellite images which were taken in different years, the presence of the extensively stratocumulus is truly proved. Therefore, the thermal concept and the dynamic concept are respectively applied to analyzing the formation of the stratocumulus cloud.
The thermal concept is displayed in Skew-T diagrams, the outcomes show there must have a temperature inversion in the boundary layer. With the temperature inversions, deep convection won't develop easily. On the other hand, the dynamic concept is fulfilled with two different resolution reanalysis data. One is NCEP-DOE Reanalysis 2 with 2.5o X 2.5o resolution, another is NCEP FNL (Final) Operational Global Analysis data with 1.0o X 1.0o resolution. Using 2013~2015 February to April data to probe the 925mb、850mb and 700mb large-scale circulation. Due to the spring time is still on the season's transition, the large-scale circulation still remain the winter characteristic of cold surge and is influenced by the rim of the northwestern Pacific subtropical high. The upper level is therefore dominated by the westerlies. In addition to the large-scale circulation, convection is vital to the cloud formation as well. The convection will induce the upward motion to finally form the stratocumulus cloud and cause precipitation.
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