NUMERICAL EXPERIMENT OF THE INFLUENCES OF HEAT AND WIND STRESS ON THE EQUATORIAL OCEAN CIRCULATION*

A time-dependent linear model on the equatorial beta plane is developed in this paper.Its vertical structure consists of two active layers with equal density and temperature above the thermocline and a quasi-stationary layer with constant density below the thermocline.The results of nurnericat experiments show that the direct influence of heat on the equatorial ocean is much smaller than that of wind stress.Nevertheless,through the tropical ocean-atmosphere interaction,the change of wind stress resulting from the thermal forcing may set a determinant effect on the equilibrium and anomalous development of the ocean-almosphere circulation.     

NUMERICAL EXPERIMENT OF THE INFLUENCES OF HEAT AND WIND STRESS ON THE EQUATORIAL OCEAN CIRCULATION

A time-dependent linear model on the equatorial beta plane is developed in this paper.Its verticalstructure consists of two active layers with equal density and temperature above the thermocline and aquasi-stationary layer with constant density below the thermocline.The results of nurnericat experiments show that the direct influence of heat on the equatorial ocean ismuch smaller than that of wind stress.Nevertheless,through the tropical ocean-atmosphere interaction,the change of wind stress resulting from the thermal forcing may set a determinant effect on the equilibriumand anomalous development of the ocean-almosphere circulation.     

TROPICAL ATMOSPHERIC NONLINEAR STEADY RESPONSE SOLUTION UNDER EFFECTS OF PAIRED HEAT SOURCES OF CONTRASTING NATURE

Based on steady semi-geostrophic model equations,analysis is carried out of the linear and nonlinearmodification/response of the tropical atmosphere to the forcing of ideal paired heat sources of contrasting nature.Re-suits show that the linear part is dominant in the steady response but the nonlinear modification is quite noticable in theneighborhood of the heat source and between the paired sources,and the barotropic mode and second baroclinic modeplay a different role in the modification,with the barotropic(second baroclinic)mode modification depending largely onthe Rossby wave self-interaction(the magnitude due to the Kelvin-Rossby wave interaction)between the pairedsources.     

计算机天气图图形识别

根据天气系统的定义和实际业务中的天气图分析规范，总结出了５００、７００、８５０ｈＰａ３层高空天气图上特征等高线，特征等温线，槽线（含切变线），高（低）中心，冷（暖）中心以及热带气旋的识别方法及其判别式，并给出了实现计算机自动识别的程序设计步骤。     

TROPICAL ATMOSPHERIC NONLINEAR STEADY RESPONSE SOLUTION UNDER EFFECTS OF PAIRED HEAT SOURCES OF CONTRASTING NATURE*

Based on steady semi-geostrophic model equations,analysis is carried out of the linear and nonlinear modification/response of the tropical atmosphere to the forcing of ideal paired heat sources of contrasting nature.Resuits show that the linear part is dominant in the steady response but the nonlinear modification is quite noticable in the neighborhood of the heat source and between the paired sources,and the barotropic mode and second baroclinic mode play a different role in the modification,with the barotropic(second baroclinic)mode modification depending largely on the Rossby wave self-interaction(the magnitude due to the Kelvin-Rossby wave interaction)between the paired sources.     

Organic geochemical studies of a recent Inner Great Barrier Reef sediment—I. Assessment of input sources

The concentration of solvent-extractable (SE) and bound hydrocarbons, ketones, alcohols, sterols, monocarboxylic acids, hydroxyacids and α,ω-dicarboxylic acids of a surface sample (0–2.5 cm) from a recent carbonate tropical sediment taken at 60ft (18m) depth north-west of the Low Isles, North Queensland, are reported in detail. n-Alkanes are a minor constituent in the SE and bound hydrocarbon fractions with the major component being unresolved complex hydrocarbon material which is not an anthropogenic input. 6,10,14-Trimethylpentadecan-2-one derived from chlorophyll, as well as phytol, were identified as major components of the ketone and alcohol constituents. No chlorophyll pigments or pigmented degradation products were present, implying degradation before incorporation into the sediment. This conclusion is consistent with evidence for higher-plant input in which all sensitive lipids have been degraded before incorporation. SE and bound fractions have been studied in detail and show considerable differences probably arising from the importance of viable biomass in the SE fraction. Inputs to the sediment are determined as higher plants, algae, bacteria, fungi and meiofauna in descending order of importance.     

西北太平洋热带气旋路径时间标度律的研究

时间标度计算表明，西北太平洋热带气旋路径是一个无标度性的系统，其关联方差谱遵从频率的－２￣－３次方幂律，不同背景下的路径系统均如此。由此得到的不同季节、不同地域的热带气旋路径可预报时间尺度基本上为３￣４ｄ，但异常热带气旋路径的可预报时间尺度则为１￣２ｄ。     

热带太平洋地区SSTA和风应力场的海气耦合模态

按国家气象局“八五”攻关力专家组提出的有关近海热带气候强度突变的标准，对１９７０－１９９１年在我国的近海发生强度突为的热带气旋进行了分类统计，发现如下气候特征：平均每年有８－９个热带气旋移到我国近海时发生强度突变，其中突然减弱的居多，占总个数的７９．６％，突然增强的只占总个数的２０．４％，突然增强只发和天５－１０月，而突然减弱到５－１２月均可发生；突然增强主要出现在浙闽沿海、南海中部，珠江口外西侧     

近百年西北太平洋热带气旋年频数的变化特征

利用经趋势订正的１８８４－１９８８年西北太平洋热带气旋年频数资料，分析了热带气旋年频数的多年变化及其与海面温度、南方涛动指数、太阳黑子数和环流型日数等的统计关系。初步结果表明，热带气旋年频数的变化具有明显的２１年、３１年、１５年和６年左右的周期和持续期平均为１２年左右的阶段变化；近百年来有三次较明显的转折，分别出现在１９３１、１９５９年１９７７年。热带气旋年频数在厄尔尼诺年有冬春季偏少、夏秋季偏多