Interaction of a Cumulus Cloud Ensemble with the Large-Scale Environment. Part III: Semi-Prognostic Test of the Arakawa-Schubert Cumulus Parameterization
Interaction of a Cumulus Cloud Ensemble with the Large-Scale Environment. Part III: Semi-Prognostic Test of the Arakawa-Schubert Cumulus Parameterization
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DOI：
10.1175/1520-0469(1982)039
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发表时间：
1982
影响因子：
3.1
通讯作者：
S. Lord
中科院分区：
文献类型：
--
作者：
S. Lord
摘要：使用半预报方法继续对荒川和舒伯特（1974）积云参数化进行验证。利用全球大气研究计划大西洋热带试验（GATE）第三阶段的观测数据，对每次观测时刻积云集合的大尺度强迫进行估计。利用该参数化计算降水以及积云对流引起的增暖和干燥的瞬时值。结果表明，计算出的降水与根据观测到的大尺度水汽收支和雷达观测所做的估计非常吻合。计算出的积云增暖和干燥的垂直廓线也与观测结果相当相似。研究表明，参数化中采用的闭合假设（云功函数准平衡）导致计算出的降水误差通常<10%。还研究了参数化对云集合模式的一些假设以及云底质量通量求解方法的敏感性。
Abstract The verification of the Arakawa and Schubert (1974) cumulus parameterization is continued using a semi-prognostic approach. Observed data from Phase III of GATE are used to provide estimates of the large-scale forcing of a cumulus ensemble at each observation time. Instantaneous values of the precipitation and the warming and drying due to cumulus convection are calculated using the parameterization. The results show that the calculated precipitation agrees very well with estimates from the observed large-scale moisture budget and from radar observations. The calculated vertical profiles of cumulus warming and drying also are quite similar to the observed. It is shown that the closure assumption adopted in the, parameterization (the cloud-work function quasi-equilibrium) results in errors of generally <10% in the calculated precipitation. The sensitivity of the parameterization to some assumptions of the cloud ensemble model and the solution method for the cloud-base mass flux is investigated.