夏季500 hPa副热带高压区域一次暴雨过程环流条件的诊断分析   总被引：4，自引：2，他引：4       下载免费PDF全文

章国材  李晓莉乔林 《应用气象学报》2005,16(3):396-401

利用NCEP/NCAR再分析资料和地面观测资料对2003年7月26～27日500 hPa副热带高压区域一次暴雨过程的形成原因进行了分析。结果表明:中低层来自东北方向的冷空气入侵是此次暴雨发生的重要原因，其作用体现在三个方面:一是致使对流层中低层降温，边界层增温，使得降水区积累了大量的不稳定能量；二是造成边界层风的辐合，进而激发了整层的上升运动；三是这股冷空气为暴雨发生提供了重要水汽源。暴雨发生前南亚高压主体突然东进，高空急流轴不断东伸加强，其出口端不断向南伸展，使得对流层中层副高主体西移，同时造成日本附近的冷涡南压，为冷空气从中低层侵入暴雨发生区提供了有利的环流条件。  相似文献   

海温和极冰对副热带高压季节性北跳影响的数值模拟   总被引：24，自引：12，他引：12  

朱玉先  喻世华 《热带气象学报》1998,14(1):38-46

道德以南海区域平均的候平均ＯＬＲ值下降至２３５Ｗ／ｍ,同时纬向风由东转成西为定义标准确定南海季风从１９７９到１９９４年间爆发的平均日期是５月第４候,然后对１６年的ＯＬＲ场,风场及θＸ场的时段叠加合成图进行了分析,认为南海夏季风的建立是南海－西太平洋系统所造成。  相似文献   

西太平洋副热带高压中期变化的数值试验 Ⅱ.热带西太平洋热源的作用     

巩远发  纪立人 《热带气象学报》1998,14(3):201-207

用一个全球谱模式作数值试验,研究了１９７９年６月中蟾一次西太平洋副热带高压西伸北进的中期天气过程中热带西太平洋地区理想热源的作用。结果表明：理想热源的作用大约在４天以后可以影响我国东部的副热带高压和中高纬度的环流;理想热源在热带洋面上产生的扰动首先沿副高南边的东风气流向西北方向传播,到中纬西风带后分为两支,一支继续向西北方向传播,另一支转向东北偏东方向传播,两支扰动的共同作用导致副热带高压和西风带  相似文献   

人工神经网络西太平洋副热带高压预报业务系统   总被引：4，自引：0，他引：4  

冯民学  陈必云 《气象科学》1998,18(4):396-402

本文应用常规500hpa资料,结合具有较稠密、高分辨的“TOVS”资料（卫星信息资料）,分析、归纳了西太平洋副热带高压大幅度北移、南蓝（120°E脊线）的经验规则,在此基础上选择了具有最优下降因子的BP算法。在人工神经网络的结构方面设计了神经网络的前处理功能,将众多的单因子经基于专家系统的前处理模块,归纳的规则,作为网络的输入端,经网络学习、训练、迭代获得了较快的收敛速度和较高的历史拟合率,建立了“人工神经网络西太平洋副热带高压预报业务系统”  相似文献   

夏季副高数值产品的集成预报研究     

晃淑懿  金荣花 《气象科学》1997,17(4):325-334

本文使用１９９５年和１９９６年６－８月欧洲中期天气预报中心和我国Ｔ６３Ｌ１６的５００ｈＰａ４８＾ｈ－１４４＾ｈ五个时效平均预报场，以及相应的Ｔ６３５０００ｈＰａ五天平均场资料，根据１００－１４０°Ｅ、２－５０°Ｎ范围内西北太平洋副热带高压的南北位置分为四类副高。对比分析ＥＣ和Ｔ６３两个模式的各类副高特征参数的预报误差特点，发现当ＥＣ预报的副高强度强于或接近Ｔ６３预报时，ＥＣ预报副高的数值产品精度优  相似文献   

近10年我国降水的QBO分析   总被引：13，自引：1，他引：13       下载免费PDF全文

陈兴芳  宋文玲 《应用气象学报》1997,8(4):469-476

近10年来我国东部地区降水分布趋势的年际变化具有QBO特征，双年的降水为中部地区少南北多，单年的降水为中部多南北少，其中江淮流域的降水变化最明显。分析表明，降水QBO的特征与西太平洋副高和冷空气活动有关，一般双年副高偏北、亚洲纬向环流发展，雨带偏北；单年相反，副高偏南、亚洲经向环流发展，雨带偏南，江淮流域降水较多。  相似文献   

中国亚热带西部山区夜雨特征的农业气候学研究   总被引：4，自引：0，他引：4  

张养才  叶一舫 《地理科学》1994,14(1):30-37

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Interdecadal change in Western Pacific Subtropical High and climatic effects   总被引：1，自引：0，他引：1  

He Xue-zhao Master degree  Gong Dao-yi 《地理学报(英文版)》2002,12(2):202-209

Western North Pacific Subtropical High is a very important atmospheric circulation system influencing the summer climate over eastern China. Its interdecadal change is analyzed in this study. There is a significant decadal shift in about 1979/1980. Since 1980, the Western North Pacific Subtropical High has enlarged, intensified, and shifted southwestward. This change gives rise to an anti-cyclonic circulation anomaly over the region from the South China Sea to western Pacific and thus causes wet anomalies over the Yangtze River valley. During the summers of 1980–1999, the precipitation is 63.9 mm above normal, while during 1958–1979 it is 27.3 mm below normal. The difference is significant at the 99% confidence level as at-test shown. The southwestward expanding of the Western North Pacific Subtropical High also leads to a significant warming in southern China, during 1980–1999 the summer mean temperature is 0.37°C warmer than that of the period 1958–1979. The strong warming is primarily due to the clearer skies associated with the stronger downward air motion as the Western North Pacific Subtropical High expanding to the west and controlling southern China. It is also found that the relative percentage of tropical cyclones in the regions south of 20°N is decreasing since the 1980s, but in the regions north of 20°N that is increasing at the same time. The Western North Pacific Subtropical High responds significantly to sea surface temperature of the tropical eastern Pacific with a lag of one-two seasons and simultaneously to sea surface temperature of the tropical Indian Ocean. The changes in the sea surface temperatures are mainly responsible for the interdecadal variability of the Western North Pacific Subtropical High.  相似文献   

Intensified mid-Holocene Asian monsoon recorded in corals from Kikai Island, subtropical northwestern Pacific     

Maki Morimoto  Hajime Kayanne  Malcolm T. McCulloch 《Quaternary Research》2007,67(2):204-214

Coupled records of Sr/Ca and oxygen isotope ratios (δ¹⁸O) of coral skeletons have been used to produce quantitative estimates of paleo-sea surface temperature (SST) and δ¹⁸O of surface seawater that can in some cases be converted to sea surface salinity (SSS). Two fossil corals from Kikai Island in the subtropical northwestern Pacific, a location affected by East Asian summer and winter monsoons, were analyzed to investigate differences between mid-Holocene and present-day SST and SSS. At 6180 cal yr BP, SSTs were roughly the same as today, both in summer and winter; δ¹⁸O_seawater and SSS values were higher both in summer (+ 0.5‰, +1.1 psu) and in winter (+ 0.2‰, + 0.6 psu) than modern values. At 7010 cal yr BP, SSTs were slightly cooler both in summer and winter (−0.8 and −0.6 °C), whereas δ¹⁸O_seawater and SSS had higher values in summer (+ 0.3‰, + 0.6 psu) and in winter (+ 0.8‰, + 1.9 psu) than present-day values. These results are consistent with other marine records for the mid-Holocene of the low and midlatitudes in the northwestern Pacific. Such regional conditions indicate that the East Asian summer and winter monsoons were more intense in the mid-Holocene, which was likely a function of the mid-Holocene insolation regime.  相似文献   

2005年7月清江流域一次连续暴雨的中尺度分析     

宋春远  熊传辉  陈亮  秦承平  罗剑琴  何明琼 《湖北气象》2007,26(1):63-67

利用气象卫星、多普勒雷达及常规气象资料,对2005年7月8～10日清江流域连续暴雨过程进行综合分析。结果表明:(1)高低空急流的优势配置、高空急流右侧强辐散场的存在,副热带高压稳定于我国东南沿海,为此次暴雨提供了有利的大尺度环境背景;(2)雨团滞留和经过区域正是暴雨发生区域;(3)低层垂直风切变可使回波加强而产生强降水;(4)雷达回波中“逆风区”对于暴雨识别及暴雨落区预报具有很好的指示性。  相似文献