海洋温带气旋爆发性发展数值试验

利用 Ｐ Ｓ Ｕ／ Ｎ Ｃ Ａ Ｒ Ｍ Ｍ ４ 对５ 个西北太平洋温带气旋的爆发性发展进行了一系列数值模拟和敏感性试验,并对重要的物理过程进行了分析和诊断。采用相同物理过程及边界条件的控制试验成功地模拟出了主要的爆发性气旋加深率,为海洋爆发性气旋的业务数值预报提供了可能。敏感性试验获得了湿物理过程、能量频散、 Ｓ Ｓ Ｔ 和海面能通量、日本岛地形及初、边值条件等影响气旋加深率的定量认识,分析表明水的微物理过程,特别是网格尺度的水汽凝结、未饱和层的云滴和雨滴蒸发,是气旋爆发性发展中最重要的物理过程;在高空 ２００～３００ｈ Ｐａ 层的云滴蒸发效应可能是形成相应层气旋中心非绝热冷却峰值的主要原因;由内在热力动力学过程所决定的潜热释放比对流参数化任意规定的加热分布更接近实际并能产生更好的模拟结果;没有能量频散效应时可减小模拟加深的 ３０％ ;海面能通量在初始时刻比在爆发性发展时更重要,不计初始时海面能通量将影响模拟加深约 ２５％ ,而不计爆发性发展时的海面能通量,这种影响不及前者的一半;爆发性发展时的海面能通量呈不均匀分布并能诱导反锋面热力环流在局部抑制气旋的加深;大气模式对海气边界层能通量交换的变化和海洋增暖产生了显著的热力学响     

AN EFFECTIVE APPROACH TO SHORT-AND MEDIUM-RANGE PREDICTION OF TRACK AND INTENSITY OF TROPICAL CYCLONES

An objective prediction approach to the 6 h-144 h track and intensity of tropical cyclones over the northwestern Pacific is proposed. On the basis of both analog deviation technique and completed historical sample curve library, the track or intensity prediction for each forecast period are determined respectively through the optimum weighted superposition of displacement or intensity change of the cases, with different number and weighted coefficient corresponding to minimal analog deviation, from different tropical cyclone or different stage of the same cyclone. so that the prediction results for both forecast period and entire process are optimal. The verification suggests that the approach exhibits better forecast performance than other previous forecast methods by having remarkable decreasing forecast errors in short-and medium-range forecast of both track and intensity,and that the approach can also be used to predict effectively the decay process of tropical cyclone and is able to predict anomalous track and tropical depression.