东部和中部型El Nino事件对云南冬季降水影响的差异分析     

周建琴  晏红明 《高原气象》2021,(1):98-108

利用1981-2017年云南125个站逐日降水观测资料和NCEP再分析资料,对比分析了两类El Nino事件期间云南冬季的降水差异,发现东部型El Nino有利于冬季云南大部地区降水显著偏多,而中部型El Nino的影响却不明显。进一步从两类事件相应的大气环流等方面分析了造成降水差异的物理原因。研究表明:(1)东部型El Nino年,Walker环流在西太平洋为异常强的下沉气流,西太平洋副热带高压偏强偏西,Hadley环流在20°N为异常上升气流,造成云南水汽输送和辐合加强,中高纬度巴尔喀什湖和贝加尔湖脊发展,冷空气沿高原东侧南下影响云南,冷暖空气在云南频繁交汇,导致云南冬季降水日数明显偏多,相应降水偏多;(2)中部型El Nino年,Walker环流在西太平洋下沉支强度较东部型弱,相应的西太平洋副热带高压较东部型偏弱偏东,Hadley环流在20°N为下沉气流,对云南区域水汽输送影响较弱,同时中高纬度环流不利于冷空气南下影响云南,除对应冬季云南东部降水日数偏少外,对其他地区降水的影响不明显。  相似文献   

热带太平洋海表能量收支平衡特征及其与两类ENSO事件的联系     

刘智媛  周连童 《气候与环境研究》2021,26(6):591-607

利用月平均的HadISST海表温度、NCEP再分析资料、OAFlux海表面热通量及相关物理量资料、NCAR/NOAA云量场资料,分析了热带太平洋海表热通量的年际特征,并且进一步分析了传统El Ni?o和El Ni?o Modoki事件中湍流热通量的异常演变特征以及影响因子。在热带太平洋上,净热通量的年际变化最大振幅出现在赤道太平洋上,且主要取决于潜热通量和短波辐射通量的变化。本文还利用两类ENSO事件旺盛期海温指数对不同时期海面热通量场的偏回归分析,考察了热带太平洋海表面热通量与两类ENSO事件中海温的联系。两类海温指数对各时期热带太平洋净热通量的回归均表现为赤道太平洋上存在显著的负异常,在Ni?o3指数偏回归下的负异常范围和强度都较El Ni?o Modoki指数回归的要大,且更偏于赤道东太平洋,而旺盛期海温对同期赤道东太平洋上湍流热通量的影响最大。  相似文献   

2006年西北太平洋热带气旋(台风)活动特征分析     

王艳萍  田志光 《海洋预报》2008,25(1):47-55

本文综述了2006年西北太平洋热带气旋(台风)的活动特征,并对2006年西北太平洋副热带高压特征量及赤道中东太平洋海温进行分析,同时对2006年的El Ni(n)o、南方涛动现象进行了简要的描述,并用500hPa月或候平均环流形势解释了2006年的台风登陆早、登陆时间集中的原因,说明500hPa月或候平均环流形势对台风登陆预报有一定的意义.  相似文献   

浙江沿海超强台风作用下的风暴潮流   总被引：2，自引：0，他引：2  

黄世昌  李玉成  赵鑫  谢亚力 《海洋通报》2008,27(5)

应用河口海岸水动力模型,利用浙江沿海包括 2 场超强台风在内的 5 场台风作用下发生的风暴潮位过程验证了该数值模式的适用性.将 1949 年以来登陆我国大陆沿海最强的"5612"号台风作为典型的超强台风,计算了超强台风在浙北至浙南 3 个不同地点登陆时产生的风暴潮流,结果显示风暴潮流一般小于天文潮潮流与基于海平面风暴海流的线性叠加值,风暴潮流场更多地呈现风暴海流的流场特点,在开敞海岸基本顺岸流动,这对于分析航道骤淤和海岸带物质输移具有重要意义.  相似文献   

超强厄尔尼诺事件次年台风生成偏晚原因分析     

李志强  张润宇  刘凯  郑昌玲  陈志昆 《海洋学报(英文版)》2019,38(7):67-73

The 2015/2016 El Ni?o event reached the threshold of super El Ni?o event, and was comparable to the super events in 1982/1983 and 1997/1998. Interestingly, the tropical cyclones(TCs) were found to have very late onsets in the decaying years of the super El Ni?o events. This study discusses the causes of late TC onsets related with atmospheric circulation, disturbance sources and trigger mechanisms. The analysis shows that the western North Pacific subtropical high(WNPSH) from January–June during the decaying years of the super El Ni?o events were stronger than the climatic mean, which resulted in a relatively stable atmospheric state by inhibiting deep convection. As a disturbance source, the April–June intertropical convergence zone(ITCZ) during the decaying years of the super El Ni?o events were significantly weaker than its climatic mean. The cross-equatorial flow and monsoon trough, as important TC generation triggers, were weaker from April–June during the decaying years of the super El Ni?o events, which further reduced the probability of TC generation. As for the late TC onsets, the role of atmospheric circulation anomalies(i.e., subtropical-high, the ITCZ, cross-equatorial flow, and monsoon trough) were more important. The cross-equatorial flow may take as predictor of TC onsets in the decaying years of the super El Ni?o events.  相似文献   

超强蜘蛛丝     

《海洋世界》2009,(5):9-9

蜘蛛丝本身就比钢丝强韧。最近，一项新研究表明，如果把蜘蛛丝和某些金属（如铝、锌、钛）融合在一起，它将变得更加强韧。在自然界中，金属的确可以增加一些生物结构的强度，但这些结构本身就比较坚硬，如动物的刺。为了检验金属对柔软结构的作用，研究者选择了蜘蛛丝。研究者用高温水蒸气破坏了蜘蛛丝蛋白之间的相互作用，然后把蜘蛛丝放在铝、锌、钛的蒸汽中，部分金属原子就与蛋白连接在一起。研究者表示，天然蜘蛛丝对湿度和温度等环境条件非常敏感，但融合了金属的蜘蛛丝几乎不受环境影响。未来，也许蜘蛛侠应该带着新型蜘蛛丝行侠仗义了。  相似文献   

The Rhyacian E1 Cortijo suture zone： Aeromagnetic signature and insights for the geodynamic evolution of the southwestern Rio de la Plata craton,Argentina     

Carlos J.Chernicoff  Eduardo O.Zappettini  Javier Peroni 《地学前缘(英文版)》2014,5(1):43-52

The amalgamation of the southern Río de la Plata craton involves two possibly coeval Rhyacian sutures associated with the Transamazonian orogeny,rather than a single one as previously envisaged,i.e.the El Cortijo suture zone and the Salado suture.We circumscribe the Tandilia terrane to the region between these two sutures.The El Cortijo suture zone runs along a roughly WNW oriented magnetic low aligned along the southern boundary of the Tandilia terrane,i.e.boundary between the Tandilia and Balcarce terranes.This extensive magnetic low,ca.300 km long,and ca.90 km wide,would be caused by demagnetization associated with shearing.At a more local scale,the trend of the El Cortijo suture zone often turns toward the EeW.At this scale,WNW trending tholeiitic dykes of Statherian age are seen to cut the Rhyacian El Cortijo suture zone.Spatially associated with the El Cortijo suture zone,there are small magnetic highs interpreted to be related to unexposed basic bodies of ophiolitic nature related to those forming part of the El Cortijo Formation.We envisage the pre-Neoproterozoic evolution of the Tandilia belt to have been initiated by the extension of Neoarchean(w2650 Ma)crust occurred during Siderian times(2500e2300 Ma),causing the separation between the Balcarce,Tandilia and Buenos Aires terranes,and the development of narrow oceans at both north and south sides of the Tandilia terrane,accompanied by w2300e2200 Ma sedimentation over transitional econtinental to oceanice crust,and arc magmatism developed in the Tandilia terrane.The island arc represented by the El Cortijo Formation was also developed at this time.At late Rhyacian times,it occurred in both the closure of the narrow oceans developed previously,the entrapment of the El Cortijo island arc,as well as anatectic magmatism in the Balcarce terrane.  相似文献   

http://www.sciencedirect.com/science/article/pii/S1674987113000571     

Carlos J.Chernicoff  Eduardo O.Zappettini  Javier Peroni 《地学前缘(英文版)》2014,5(1)

The amalgamation of the southern Río de la Plata craton involves two possibly coeval Rhyacian sutures associated with the Transamazonian orogeny,rather than a single one as previously envisaged,i.e.the El Cortijo suture zone and the Salado suture.We circumscribe the Tandilia terrane to the region between these two sutures.The El Cortijo suture zone runs along a roughly WNW oriented magnetic low aligned along the southern boundary of the Tandilia terrane,i.e.boundary between the Tandilia and Balcarce terranes.This extensive magnetic low,ca.300 km long,and ca.90 km wide,would be caused by demagnetization associated with shearing.At a more local scale,the trend of the El Cortijo suture zone often turns toward the EeW.At this scale,WNW trending tholeiitic dykes of Statherian age are seen to cut the Rhyacian El Cortijo suture zone.Spatially associated with the El Cortijo suture zone,there are small magnetic highs interpreted to be related to unexposed basic bodies of ophiolitic nature related to those forming part of the El Cortijo Formation.We envisage the pre-Neoproterozoic evolution of the Tandilia belt to have been initiated by the extension of Neoarchean(w2650 Ma)crust occurred during Siderian times(2500e2300 Ma),causing the separation between the Balcarce,Tandilia and Buenos Aires terranes,and the development of narrow oceans at both north and south sides of the Tandilia terrane,accompanied by w2300e2200 Ma sedimentation over transitional econtinental to oceanice crust,and arc magmatism developed in the Tandilia terrane.The island arc represented by the El Cortijo Formation was also developed at this time.At late Rhyacian times,it occurred in both the closure of the narrow oceans developed previously,the entrapment of the El Cortijo island arc,as well as anatectic magmatism in the Balcarce terrane.  相似文献   

Meridional Variation of the 1955-2003 Sea Level Anomalies in the Tropical Pacific Ocean Associated with El Nio Events     

FANG Mingqiang)  )  and QU Liqin)  )) Ocean Remote Sensing Institute  Ocean University of China  Qingdao  P. R. China ) The Key Laboratory of Ocean Remote Sensing  Ministry of Education  P. R. China 《中国海洋大学学报(英文版)》2007,(4)

The Sea Level Anomaly-Torque (SLAT, relative to a reference location in the Pacific Ocean), which means the total torque of the gravity forces of sea waters with depths equal to the Sea Level Anomaly (SLA) in the tropical Pacific Ocean, is defined in this study. The time series of the SLAT from merged altimeter data (1993-2003) had a great meridional variation during the 1997-1998 El Nio event. By using historical upper layer temperature data (1955-2003) for the tropical Pacific Ocean, the tempera- ture-based SLAT is also calculated and the meridional variation can be found in the historical El Nio events (1955-2003), which suggests that the meridional shifts of the sea level anomaly are also intrinsic oscillating modes of the El Nio cycles like the zonal shifts.  相似文献   

1961年-2012年山西雾霾的时空变化特征及成因分析     

王咏梅  武捷  褚红瑞 《山西气象》2013,(4):23-30

利用1961年-2012年山西逐日天气现象、能见度、相对湿度和日平均气温资料,采用Kendall-tau方法和相关分析法研究山西雾霾日数的时空变化特征及成因。结果表明：雾多发区在中南部,北部雾日较少。霾、烟幕日数高值区出现在以大同、太原、临汾为中心线的带状区域。季节分布来看,轻雾、雾日数峰值出现在8、9月份,谷值在5月份出现;霾和烟幕日数的峰值出现在12、1月份,谷值在8、9月份出现。近50余年以来,山西雾霾日数呈现增多趋势,雾日增加趋势较弱,60、70年代为增多趋势,进入21世纪则为减少趋势;轻雾和霾日数均为显著单调上升趋势;烟幕日数也为显著增多趋势,但表现为抛物线型,90年代后期以前为增多,之后转为下降趋势。山西霾和烟幕日数与E1Nino事件有很好的对应关系,E1Nino事件发生年往往霾和烟幕日数较多,赤道中东太平洋的海温异常通过海气相互作用,引起东亚地区上空的大气环流异常,形成利于霾和烟幕出现的天气条件。山西冬季气温偏高往往导致霾和烟幕天气的增多,气候变暖对霾和烟幕天气的影响不容置疑。  相似文献