- 作者: 袁撰英;劉雅章
- 作者服務機構: 德州農工大學氣象系地球流體動力實驗所
- 中文摘要: 本文發表一個一維雲化學模式,並應用此模式研究硫化物在暖積雲中的垂直輸送,化學反應,和沈降。此模式由一動力副模式和一硫化學副模式組成。動力副模式包含兩個同心空氣圓柱;微物理和湍流過程以參數處理。硫化學副模式以一個反應系統模擬在積雲內的液態化學反應。模式預測的積雲動力結構曾先試驗,發現與其他研究相符。 研究結果指出,積雲有效地將邊界層硫化物輸送到自由大氣。二氧化硫先溶在雲滴內,被強烈的向上氣流帶越邊界層。隨後雲滴受向下氣流影響而蒸發,使二氧化硫變回氣態而留在自由大氣。在自由大氣的硫化物粒子則主要來自雲頂的向外氣流。此研究亦發現二氧化硫在液態的氧化過程是產生酸雨的重要機制。
- 英文摘要: A one-dimensional, time-dependent numerical model is developed to study the scavenging, transfor-mation, and vertical transport of sulfur compounds associated with warm cumulus clouds. The model hastwo modules: a dynamics module and a sulfur chemistry module. The dynamical framework consists oftwo circular concentric air columns with parameterized microphysics and turbulent transport processes.The sulfur chemistry module simulates in-cloud chemical oxidations with an aqueous phase reaction system. The dynamical features predicted by the model are tested and found to beconsistent with other studies. It is found that cumulus clouds are effective in transporting sulfur com-pounds up above the planetary boundary layer. is dissolved in hydrometeors and carried upward byintense updrafts. Subsequent evaporation of cloud water caused by downdrafts leads to considerabledegassing of above the planetary boundary layer. Sulfates at the higher levels are contributed mainlyby lateral outflow of sulfur-bearing hydrometeors at about 2 km, the typical top level of low clouds. It isalso found that the aqueous phase oxidation of dissolved is a significant mechanism in the formationof acid precipitation·
- 中文關鍵字: Acid precipitation; sulfur species; in-cloud oxidation; aqueous phase chemical kinetics
- 英文關鍵字: --