• 作者： 陳泰然
• 作者服務機構： 國立臺灣大學大氣科學研究所
• 中文摘要： 本文利用發生於冬季季風實驗期間1979年2月21 - 22日個案，研究華中之低對流層鋒生過程。此期伴隨雲貴背風旋生之華南低層強烈西南氣流與蒙古冷高壓前緣之盛行東北風，提供一個在華中鋒生之有利變形場。分析850mb之位溫梯度及鋒生方程內各項強迫過程，並分析其垂直剖面分佈，以利診斷。 結果顯示，華中鋒生主要由伸展（或合流）變形強迫作用而來，風切變形對鋒生貢獻不大，而扭轉項在鋒生時期抵消一部份合流強迫作用。鋒面上弱低壓西北之鋒生，主要由風切變形而來，此恰似發展中溫帶氣旋之冷鋒增強情況。鋒消主要由扭轉項導致，此項似由中對流層而非由低對流層之過程而來。
• 英文摘要： An observational study was carried out for a case of lower-tropospheric frontogenesis over Chinaduring the period of February 21-22, 1979 of winter MONEX. During this period, the unseasonably strongsouthwesterlies over subtropical China accompanying the Yun-Guai lee cyclogenesis together with the north-easterlies from the Mongolia cold anticyclone provided a favorable deformation wind field for frontogenesisover central China. Potential temperature gradients and different adiabatic frontogenetical forcings wereanalyzed at 850 mb. These were also presented along selected cross sections to help the diagnosis. Results showed that frontogenesis over central China was primarily due to Bergeron confluenceforcing. The effect of shearing deformation to the frontogenesis was rather insignificant. The twisting termcounteracted part of the confluence forcing in the frontogenetic phase. Frontogenesis to the northwest ofthe weak frontal cyclone was mainly due to the shearing deformation similar to the situation of an intensi-fying cold front in a maturing extratropical cyclone. Frontolysis was primarily caused by the twisting termwhich appeared to be due to the processes in the mid-troposphere rather than in the lower troposphere.
• 中文關鍵字： MONEX; frontolysis; frontogenesis; shearing deformation; stretching deformation
• 英文關鍵字： --