WATER AND ENERGY CYCLE IN SUBTOPICS

夏季东亚副热带季风区的能量和水分循环以梅雨锋为主要特征。GAME/HUBEX的目的之一是研究中尺度云系的演变。本研究的主要目的是阐明中尺度云系在区域尺度能量和水循环时间变化中的作用，揭示中尺度云系的演变及其对陆面系统时间变化的响应。继1998年之后，HUBEX小组还在1999年进行了气象观测：地面通量观测和6、7月（白乌季）气象水文的密集实地观测。主要观测项目有：15个测点的探空观测，阜阳天气雷达观测，寿县和丰台多普勒雷达观测，密集雨量计观测，自动气象站长期观测，以及通量观测。天气尺度形势与上一季有很大不同。在密集的实地观察期间，观察到几种类型的降水。利用JSM（Japan Spectral Model）、MRI-NHM和Yamasaki的模式，对IOP期间中国大陆上空的一个云团进行了数值模拟研究。这些模式成功地模拟了云团，并将模拟结果与观测结果进行了比较。HUBEX集团组织了国际会议和研讨会：1999年11月3日至9日在中国Xi举行的讲习班，在札幌举行的国际会议，2000年9月12日至14日在日本举行的第三届GAME-HUBEX梅雨中尺度系统研讨会和题为“第三届GAME-HUBEX梅雨中尺度系统研讨会”的国际会议。2001年12月在中国的“白乌锋及其水文循环”。会议上发表了多篇论文，并进行了富有成效的讨论。

The energy and water cycle in the subtropical monsoon region of the East Asia is characterized largely by Baiu/Meiyu front in summer. One of purposes of GAME/HUBEX is to study the evolution of mesoscale cloud system. Main objectives of this study are to clarify roles of a mesoscale cloud system in time variation of regional-scale energy and water cycle and to reveal evolution of a mesoscale cloud system and its response to time variation of land-surface system.Following 1998, HUBEX group also performed meteorological observation in 1999 : surface flux observations and the intensive field observation of meteorology and hydrology in June and July (Baiu season). Main observations are as follows, radiosonde observations at 15 points 4 times a day, weather-radar observations at Fuyang, Doppler radar observations at Shou-xian and Feng-tai, dense raingauge observations, AWS long term monitoring, and flux observations.The long term monitoring of flux are continued since the last year. Synoptic-scale situation was largely different from the last Baiu season. During the intensive field observation, several types of precipitation were observed. In particular, precipitation was significant during the period from 21 June to 8 July.Modeling studies have been performed about a cloud cluster observed over the China continent during the IOP using JSM (Japan Spectral Model), MRI-NHM, and Yamasaki's model. The cloud cluster was successfully simulated by these models and the results were compared with observation.HUBEX group organized international conferences and workshops : the workshop Xi'an, China on 3-9 November 1999, the international conference in Sapporo, Japan on 12-14 September 2000 and international conference entitled as"The Third GAME-HUBEX Workshop on Meso-scale Systems in Meiyu/Baiu Front and its Hydrological Cycle" in China in December 2001. Many papers were presented in there conferences and fruitful discussion was carried out.