大气环流与热带气象.pdf

第六章 :大氣環流與熱帶氣象 1. 全球地面氣壓系統季節分布 2. 單胞環流與三胞環流（熱平衡與動量平衡） 3. 熱帶幅合帶 (ITCZ) 4. 熱帶波動 (tropical disturbances) 5. 非洲東風波(African easterly waves) 6. 熱帶季風 (monsoons) 7. 瓦克環流(walker circulation) 8. 聖嬰現象和南方震盪 (ENSO) 9. 熱帶季內震盪 (Intra-seasonal oscillations) 一月份大氣環流特徵。 Semi-permanent high and lows, Bermuda high and Pacific high, Iceland low and Aleutian low, Siberian high and Canadian high. Thermal low, monsoon low, cyclonic and anticyclonic circulation, and intertropical convergence zone. 七月份大氣環流特徵。Notice the significant difference between summer time and winter time surface pressure and wind systems. 大氣運動的 能量循環 地球大氣系統的年平均全球能量平衡。 太陽輻射、大地輻射、雲、大氣－地面－海洋之 交互作用。 Consider a perpetual earth, no rotation, covered with water on the surface, and the sun is always directly above the equator, the general circulation of the Earth will be a single cell circulation, i.e., Hadley cell, a thermal direct cell 。 （a ）一佈滿水、旋轉地球的理想風場和地面氣壓分佈。 （b ）一佈滿水、旋轉地球地面風常和氣壓系統名稱。 大氣環流的主要氣壓系統、理想空氣運動、降水的分佈 （藍色表降水較多）。 對流層頂和噴射氣流 Tropical dynamics: The observed structure of large-scale tropical circulations • Due to their energy sources, as well as the smallness of the Coriolis parameter, large-scale equatorial motions have several distinctive characteristic structural features that are quite different from those of mid-latitude systems. 6.1:Intertropical convergence zone (ITCZ) • The tropical general circulation was thought to consist of a thermally direct Hadley circulation in which air in the lower troposphere in both hemispheres moved equatorward toward the ITCZ where by continuity considerations it was forced to rise uniformly and move poleward , thus