WAVELET ANALYSIS OF INTERANNUAL VARIATION OF TROPLCAL CYCLONES IN GUANGDONG

Climatological laws are studied for the annual frequency of tropical cyclone occurrence and the date of the yearly first landfall,which take place in the Guangdong province or pose serious threats on it from 1951 to 1999,using the data in the Yearly Book on Typhons.A new method that has developed over recent years for the study of temporal sequences,the wavelet analysis,is used,in addition to more common statistical approaches.By analyzing two wavelet functions,HAT and MORLET,we have compared the results of transfor proaches.By analyzing two wavelet functions,MHAT and MORLET,we have compared the results of transformation of the wavelets provided that ther conditions remain unchanged.It is discovered that the variance of MORLET wavelet has better indication of primary periods; period-time sequence charts can reflect major affecting periods for individual sections of time;when compared with the orginal sequence,the chart shows a little shift.On the other hand,such shift is absent in the MHAT wavelet.but its higher frequency part of variance covers up the primary periods to make its variance less pedominant as compared to the MORLET wavelet.Besides,the work compares two different assumptions of an amplifying factor a.It is found that primary periods can be shown more clearly in the variance when a takes the exponential of 2 than it takes values continuously.Studying the annual frequency of tropical cyclones and the date of first appearance for periodic patterns ,we have found that the primary peroids extracted by this approach are similar to those obtained by wavelet transformation.     

RELATIONSHIP BETWEEN INTERANNUAL VARIATION OF MERIDIONAL WIND ANOMALIES IN TROPICAL PACIFIC AND SSTA

The Singular Spectrum Analysis (SSA) method is used to conduct studies of periodicity of the SST and meridional winds in tropical Pacific Ocean. The results show that the air-sea system for the Pacific varies on quasi-4-year, quasi-2-year and interannual scales, with the quasi-4-year scale having the highest variability. Depending on the scale, the wind field has a varying degree of association with the SST anomalies. Difference is also found in the evolution of phase. In addition, the work discusses the difference in SSTA resulted from wind fields for quasi-4-year and quasi-2-year components.     

ON THE PREDICTION OF TROPICAL CYCLONE LANDFALL AND INFLUENCE ON SOUTHERN CHINA USING MONTHLY OLR ANOMALIES FOR PRIME SUMMER

With the OLR data,the landfall and activity of tropical cyclones(TC) in southern China over a 20-year period(1975～1994) are studied.The result shows that the variation of the monthly anomalous OLR is somewhat teleconnected with the TC activity in southern China.The former is used to predict short-term climate for the latter over months with frequent or no TC influence.To some externt,the relationship between the TC activity in southern China and the monthly mean OLR anomalies is dependent on the climatological location of the subtropical high in northwestern Pacific region.     

影响山东半岛风暴潮的分析和预报

通过对1981－1998年烟台、成山头的潮汐资料和日最大增水高度资料及实时天气资料的分析，给出了山东半岛的潮汐和风暴潮的气候特征，影响山东半岛风暴潮的主要天气系统有气旋、冷锋和热带气旋；用最优子集回归建立了气旋类、冷锋类型的防风暴潮的预报方程，对热带气旋造成山东半岛的风暴潮进行了定性分析并给出了该类型的预报方法，建立了山东半岛防风暴潮的预报警报系统。通过1999年1－7月的试报，计算气旋类和冷锋类增水的最大误差为13．9cm，最小为2．6cm。     

“2000．10”海南岛大暴雨成因分析

引发2000年10月13－15日海南岛洪灾的起因，源于南海热带低压、冷空气、低空东风急流等天气系统的相互叠加，以及充沛的水汽输送，冷暖空气在海南岛上空交缓所致。     

广西特大暴雨的特征分析

对1971－2001年发生在广西的特大暴雨和特大暴雨天气过程的时空分布特征及其环流形势特点作一较系统的分析，得出广西特大暴雨的月际分布具有明显的“单蜂型”，多发区域在沿海地区，造成广西特大暴雨的影响系统主要是热带气旋或热带低压系统。     

攀枝花市旅游气候资源分析及开发建议

利用攀枝花市长年代、高质量的气象观测资料,分析了攀枝花的气候特点,把分析结果与一些著名旅游城市比较,发现攀枝花市"冬暖"得天独厚,它是本地区旅游业开发的主要自然资源之一.然而,为了使旅游业成为近期本市经济的一个快速增长点,必须大力发展特色旅游.从长远的观点看,为了使全市旅游业可持续发展,在发展生态观光旅游的时候,我们必须加强生态环境保护和建设,那么未来攀枝花市的社会经济发展与自然资源环境将进入良性循环,从而找到具有攀枝花市特点的旅游发展模式.     

热带平流层臭氧准两年周期振荡的特征及数值模拟

利用HALOE的观测资料、对热带地区平流层臭氧垂直分布的年际变化及其准两年周期振荡（QBO）进行研究，并同赤道上空平均的纬向风场的准两年周期振荡进行了模拟研究。资料分析结果表明，平流层臭氧浓度高值区的位置在南北方向上和垂直方向上的有明显的准两年周期，臭氧浓度高值中心的南北移动和上下移动又引起局地臭氧总量的周期性变化和准两年周期振荡南北半球不对称。而臭氧浓度中心位置的准两年周期变化与赤道上空平均纬向风的准两年周期振荡密切相关。资料分析还表明，赤道上空平流层中臭氧浓度QBO的位相随高度变化多次。模拟试验表明，纬向风QBO引起垂直经圈环流的变化，在平流层有三对余差环流圈。它们对O3在不同纬度和高度的输送是引起O3准两年周期振荡的重要动力原因。其中，余差环流在平流层中层（25－35km)的环流圈起着重要的作用。     

准噶尔南缘-吐鲁番盆地晚二叠世-中三叠世早期二齿兽类的发育及生态环境探讨

准噶尔南缘-吐鲁番盆地晚二叠世-中三叠世早期地层中、共有5个岩组发现有二齿兽类化石。这些二齿兽类生活在河流-浅水湖泊的古地理环境中，伴随古气候条件为热带-亚热带气候。该时期的“红层”可以作为热带-亚热带气候的标志之一。     

中国热带红树林的发展及其地理背景

参照约３０个红树林孢粉分析实例，探讨中国南方晚第三纪以来红树林的发展。红树林开始出现于晚始新世；晚第三纪其分布比今偏北；第四纪冰期使红树林向南退缩至雷州半岛北部。末次间冰期４２ ０００～２５ ０００ ａ ＢＰ红树林扩展，以海桑属为代表的典型红树林的北界从现今的 １９°３０′扩展到２３°４０′Ｎ。末次冰期红树林衰落。早全新世９ ６００～７ ９００ ａ ＢＰ红树林复兴，中全新世达到繁盛，向北分布到闽江口（２６°Ｎ），与现今的北界一致，但是中全新世以来海桑属在１９°３０′Ｎ以北不再出现，奠定了现今红树林地带性分布的格局。