• 作者： 柳中明; 黃柏銘
• 作者服務機構： 台灣大學大氣科學系
• 中文摘要： 本研究主要發展一個雲滴凝結成長的綜觀模式，以求解雲滴分布函數隨時間的變化，並分別運用於封閉與開放系統。所求得之分布函數與Howell(1949)依據水汽擴散成長理論所得之結果相似，但所需之電腦運算時間顯著減少。在開放系統中，所獲之雲滴分佈譜且與Fitzgerald(1972)之觀測與模擬結果相似。此模式被命名為隨機凝結模式，因為其特性與隨機收集模式相似，並且可以考慮環境與系統間相互作用所造成之雲滴譜擾動。本中詳細討論本模式與微觀理論之相關，以及與隨機收集模式之分野。
• 英文摘要： A macroscopic model of cloud droplet growth by condensation is formulated by modifying the logisticequation used in ecology. In this model, time-dependent distribution functions of cloud droplets are derivedfor closed and an open systems, respectively. These functions have characteristics similar to those drawnfrom the diffusional growth theory of Howell (1949) but require much fewer computational resources.The computed spectrum for an open system matches very well with the spectra computed and observedby Fitzgerald (1972). This model can be called a stochastic condensation model, because it solves forthe same droplet distribution function as does the stochastic collection model and, moreover, deals withthe stochastic variation of the droplet spectrum caused by diffusive interactions with the surroundings.The physical meaning and possible relationship to the current microscopic condensation theories arepresented. Also, some ambiguities between this stochastic condensation model and the stochastic collectionmodel are clarified. The advantage of taking the droplet distribution function as a predictor is that itmakes the developed model ready to be combined with the stochastic collection model in simulating thecondensation, collision-coalescence and breakup processes simultaneously, which will be illustrated ina coming paper.
• 中文關鍵字： cloud physics; condensational growth
• 英文關鍵字： --