共查询到20条相似文献，搜索用时 31 毫秒
1.
南北半球副热带高压对赤道东太平洋海温变化的响应 总被引：16，自引：0，他引：16
本文利用1974年1月到1996年12月重分析(NOAANCEP-NCARCDAS-1)全球500hPa位势高度场资料,及同期赤道太平洋各海区SST资料,研究了南北半球副热带高压的变化特征及其对赤道东太平洋SST变化的响应。结果表明,全球副热带高压的变化及对SST的响应,在南北两个半球有很好的一致性。全球副热带高压强度的变化与超前3个月SST的正相关最为显着。对SST响应最强烈的区域主要在南北纬30°之间的低纬,低纬地区局地SST对副热带高压也有强烈的影响。从10°到30°纬度,对SST的响应分别落后于赤道2～9个月。在中、高纬大气环流的响应表现为波列特征,对暖SST及冷SST的响应波列基本相反,但对暖SST的响应更为显着。海温和副热带高压的月际持续性有明显的季节变化,副热带高压9-10月的相关障碍可能与NinoC区SST8-9月的相关障碍低点有关。 相似文献
2.
东南沿海前汛期与后汛期降水的比较分析 总被引：3，自引：1，他引：3
本文通过对东南沿海前汛期降水与后汛期降水的多年气候变化及500hPa环流场和北太平洋海温场对比分析发现:前汛期降水与后汛期降水在年代际变化上差异明显。前汛期降水逐年变化幅度小,大旱、大涝年少;后汛期降水逐年变化幅度大,大旱、大涝年多。前汛期降水与后汛期降水的大旱、大涝年环流形势场和海温场均存在明显差异。在与北半球500hPa高度场和北太平洋海温场的相关分布上,表现出基本相反的分布类型。计算分析还发现,前期8～9月和冬季1～2月北半球副高,尤其是太平洋副高与前汛期降水相关尚好。前期1月赤道洋流区中部海域的海温,对前汛期降水均有较好的预测指示意义。前期2月北大西洋涛动和黑潮区以东至太平洋中部海域的海温对后汛期降水具有较好的预测指示意义。 相似文献
3.
通过分析福建省出现秋台年与无秋台年夏季几个物理因子的变化，得出如下结论(1)有秋台年夏季东亚500hPa高度距平场呈现“－＋－”的分布特征，无秋台年东亚500hPa高度距平场呈“＋－＋”的分布.(2)有秋台年夏季副热带高压较活跃，北进南退的步伐较大，而无秋台年只在秋季的回跳速度快.(3)拉尼娜事件开始年份可能会出现秋台风，同时有秋台年夏、秋季海温距平分布是赤道中、东太平洋为负的海温距平，西、北太平洋为正海温距平，无秋台年份海温的分布形态与此刚好相反． 相似文献
4.
5.
Relation between sea surface temperature anomaly in the Atlantic and summer precipitation over the Northeast China 总被引：1，自引：0，他引：1
1 IwrRoDUcrIowln recen l00 years. mateorolQgi8ts have paid mu0h aneation to impact of ocean onlong-range weather process. Because fram view POillt of space and tAne scale condition,ocean is one of very important phySical factor for the evolotion of thespheric circulation.The scientific research cooperation grOup (l979) first found that SST in the equatorialeastern Pacific reversely correlates with summer tempendre aver Nowheast China. Pan etal (1981) discussed re1atfon between heating of… 相似文献
6.
评估了23个IPCC-AR4模式在低纬地区1948—1999年7—9月大尺度环流场的模拟性能,重点关注西北太平洋区域的西太副高、季风槽以及台风活动海域的垂直风切变。结果显示,绝大多数模式的7—9月低纬地区500hPa平均高度场、850hPa风场空间分布与NCEP都具有很高的相似性,但大多模式500hPa高度场存在系统性偏低,而850hPa风场偏强。所有模式模拟的西北太平洋副高脊线与NCEP都有一致的西南-东北走向,但有些模式的脊线位置偏离NCEP的较远。有4个模式没有模拟出类似于NCEP的季风槽线。综合模式对夏季热带环流场、西北太平洋副热带高压、季风槽以及西北太平洋热带气旋活动关键区域垂直风切变气候特征的模拟性能,按性能优劣,排在前10的模式依次是mpi_echam5、cccma_t63、gfdl_cm2_1、cnrm_cm3、cccma_t47、ukmo_hadgem1、ingv_echam4、ncar_ccsm3_0、csiro_mk3_5、mri_cgcm2_3_2a;排在后6位的模式是inmcm3_0、iap_fgoals1_0_g、ipsl_cm4、miroc3_2_medres、giss_eh、giss_er。 相似文献
7.
中国近海海温年际年代际振荡关键海区分析研究 总被引：1，自引：0，他引：1
用HADLEY中心的HadISST的海温资料、NCEP的大气资料、国家气象局发布的74个月平均环流指数和美国华盛顿大学的PDO指数,讨论研究了中国近海海温的年际年代际振荡。通过对我国近海海温的EOF分析,可以发现我国近海30 N附近是海温年际年代际振荡信号最强的关键区,它占了总量的58.2%,与澳大利亚东北沿海海温年代际振荡有相同的周期,最明显周期是44—45年,滞后PDO信号近15年左右。该关键区海温与澳大利亚东北沿海海温都还存在1年、5年和15年的振荡,它们的相关系数达到0.604,属于同一个模态。另外,1年的海温振荡信号除了澳大利亚东北沿岸以外,还沿着西太平洋海岸线分布,因此中国近海海温年际年代际振荡不是一种局地现象,而与太平洋海温变化有关。另外,它是海气相互作用的结果,与中高纬度的东亚大槽和低纬度太平洋印度洋的风场、西太平洋副高和南海副高、大气温度场甚至南半球环流有明显的关系。 相似文献
8.
Interdecadal modulation of interannual atmospheric and oceanic variability over the North Pacific 总被引：1，自引：0，他引：1
The interdecadal modulation of interannual variability of the atmosphere and ocean is examined over the North Pacific by using Wavelet Transform combined with Empirical Orthogonal Function (EOF) or Singular Value Decomposition (SVD) analysis. For the period of record 1899–1997, the interannual variability of the wintertime Aleutian Low, identified by either the North Pacific Index or the leading eigenvector (EOF-1) of North Pacific sea level pressure (SLP), exhibits an interdecadal modulation. Interannual variance in the strength of the Aleutian Low was relatively large from the mid-1920s to mid-1940s and in the mid-1980s, but relatively small in the periods from 1899 to the mid-1920s and from the mid-1940s to the mid-1970s. The periods of high (low) interannual variability roughly coincide with pentadecadal regimes having a time averaged relatively intense (weak) Aleutian Low. Consistent with this SLP variability the interannual variance in the zonal wind stress is strengthened in the central North Pacific after the 1970s. The SLP EOF-2, which is related to the North Pacific Oscillation, exhibited a strengthening trend from the beginning of this century to the mid-1960s. After the 1970s, the interannual variance of SLP EOF-2 is generally smaller than that in the period from 1930 to 1970. Similar interdecadal changes in interannual variance are found in expansion coefficients for the first two EOFs of the Pacific sector 500 hPa height field for the period 1946–1993. EOF-1 of Pacific sector 500 hPa corresponds to the Pacific/North American (PNA) teleconnection pattern, while EOF-2 is related to the Western Pacific (WP) pattern. The relative influence of the atmospheric PNA and WP interannual variability on North Pacific SSTs appears to have varied at pentadecadal time scales. Results from an SVD analysis of winter season (December–February) 500 hPa and North Pacific spring season (March–May) SST fields demonstrate that the PNA-related SST anomaly exhibited larger interannual variance after the 1970s, whereas the interannual variance of the WP related SST anomaly is larger before the 1970s. Correlations between the coastal North Pacific SST records and gridded atmospheric field data also change on interdecadal time scales. Our results suggest that the SST records from both the northwest and northeast Pacific coasts were more closely coupled with the PNA teleconnection pattern during the periods of 1925–1947 and 1977–1997 than in the regime from 1948 to 1976. Teleconnections between ENSO and preferred patterns of atmospheric variability over the North Pacific also appear to vary on interdecadal time scales. However, these variations do not reflect a unique regime-dependent influence. Our results indicate that ENSO is primarily related to the PNA (WP) pattern in the first (last) half of the present century. Correlation coefficients between indices for ENSO and PNA-like atmospheric variability are remarkably weak in the period from 1948 to 1976. 相似文献
9.
南海表层水温场的时空特征与长期变化趋势 总被引：9，自引：0，他引：9
本文利用月平均表层水温（SST）、850hPa经向风和西太平洋副热带高压等资料分析了南海表层水温距平（SSTA）场的时空特征和长期变化趋势，并探讨了SST的年际和长期变化原因．结果表明，南海SSTA场分别存在着以全域同位相振荡和东南一西北向反位相振荡的两个主要模态．其中，前者是主要模态，以年际振荡为主，而后者则是次要模态，以季节振荡为主．进一步分析发现，南海中部的SST存在着显著的年际和年代际变化，并在1981年前后发生了一次由低到高的气候转变，而且南海中部SST的长期变化趋势非常明显，在1950—2006年间增温0．92℃．相关和合成分析表明，南海SST的年际和长期变化可能是由南海上空的经向风异常和西太平洋副热带高压的纬向变动引起的． 相似文献
10.
Various statistical methods (empirical orthogonal function (EOF), rotated EOF, singular value decomposition (SVD), principal
oscillation pattern (POP), complex EOF (CEOF) and joint CEOF) were applied to low-pass filtered (>7 years) sea surface temperature
(SST), subsurface temperature and 500 hPa geopotential height in order to reveal standing and propagating features of decadal
variations in the North Pacific. Four decadal ocean-atmosphere covariant modes were found in this study. The first mode is
the well-known ENSO-like mode associated with the “Pacific-North American” atmospheric pattern, showing SST variations reversed
between the tropics and the extratropics. In the western tropical Pacific, subsurface temperature variations were found to
be out of phase with the SST variations. The other three modes are related to the oceanic general circulation composed of
the subtropical gyre, the Alaskan gyre and the subpolar gyre, respectively. The 1988/89 event in the northern North Pacific
was found to be closely associated with the subtropical gyre mode, and the atmospheric pattern associated with this mode is
the Arctic Oscillation. An upper ocean heat budget analysis suggests that the surface net heat flux and mean gyre advection
are important to the Alaskan gyre mode. For the subpolar gyre mode, the mean gyre advection, local Ekman pumping and surface
net heat flux play important roles. Possible air-sea interactions in the North Pacific are also discussed. The oceanic signals
for these decadal modes occupy a thick layer in the North Pacific, so that accumulated heat content may in turn support long-term
climate variations.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
南印度洋副热带偶极子型海温异常与全球环流和我国降水变化的关系 总被引：9，自引：1，他引：9
用1951~2001年观测资料,研究了南印度洋副热带偶极子型(IOSD)海温异常对全球500hPa环流和我国降水的影响.结果表明,冬季IOSD激发出极显著的南北半球环绕太平洋的波列结构(CP),其年际变化周期是2.0和6.5 a,与赤道中东太平洋海温也有密切联系.北半球冬季异常峰值后的第二年春季欧亚中高纬度地区500 hPa环流出现显著的EUP型低频流型持续异常,同时中太平洋和北美地区出现CPNP流型和澳大利亚南部的南半球中高纬地区呈现极显著的西南太平洋遥相关型(SWP).当冬季赤道南印度洋副热带呈极显著的西负东正海温距平分布时,后期春季欧亚中高纬地区负EUP型遥相关波列持续偏强,导致东亚大槽明显偏弱,长江以北地区(特别是黄河中上游地区)多雨.反之,春季东亚大槽加强且稳定,我国东部地区大范围少雨.它反映了南印度洋地区海气系统相互作用与东亚热带内外环流低频变化的联系.因此,上一年冬季南印度洋副热带偶极子型(IOSD)海温异常强度是预测春季华北地区旱涝变化的重要因子之一. 相似文献
12.
1997年影响南海的热带气旋异常活动特征及成因分析 总被引：2，自引：0，他引：2
统计分析了近30年(1976-2005)来影响南海的热带气旋特征,对1997年影响南海的热带气旋异常活动的成因作了进一步的分析.结果表明,El Nino发生后,西北太平洋生成的热带气旋以偏少为主,强度偏强,且热带气旋生成位置偏东,热带低压加强成为热带风暴的平均位置也较多年平均位置偏东;副热带高压强度和Nino 3.4区SST变化趋势基本一致,但副热带高压强度变化落后SST变化6个月左右.由于El Nino事件多发生于上半年,赤道中东太平洋Nino 3.4区SST偏高,当年冬季或次年春夏季往往副热带高压异常偏强;El Nino发生年的次年,暖水向西回涌,西太平洋海温逐渐恢复正常,副高强度偏强. 相似文献
13.
黑潮弯曲时的北太平洋冬季海温异常对大气低频振荡的影响 总被引：2，自引：1，他引：2
利用中科院大气物理研究所开放实验室ＩＡＰ－ＡＧＣＭ（二层大气环流模式），针对黑潮弯曲时的北太平洋冬季表层海温（ＳＳＴ）异常进行八个月的数值积分试验。试验结果表明：黑潮弯曲时北太平洋冬季ＳＳＴ异常对大气低频振荡的影响具有明显的３０－６０ｄ振荡的特征；在北半球的３０－６０ｄ振荡，大部分地区为向西传播，在南半球则为向东传播；其经向传播较为复杂，在１２０°Ｅ剖面上以向南传播为主；热带地区受此ＳＳＴ异常的影响以西太平洋、印度洋大气加热场的３０－６０ｄ振荡为主要标志。 相似文献
14.
2020年秋季(9—11月)大气环流特征表现为,北半球极涡呈单极型分布,中高纬环流呈4波型。9—11月,欧亚大陆中高纬环流经向度不断加大,冷空气势力增强。西太平洋副热带高压较历史平均偏强,热带气旋活动频繁。我国近海出现了19次8级以上大风过程,其中冷空气大风过程6次,台风大风过程4次,入海气旋大风过程1次,冷空气与热带气旋共同影响的大风过程7次,冷空气和温带气旋共同影响的大风过程1次。西北太平洋和南海共生成13个热带气旋,其中10月共有7个热带气旋生成,追平10月热带气旋生成数的历史最高纪录;全球其他海域共生成热带气旋26个。我国近海未出现2 m以上大浪过程的天数仅有12 d,约占秋季总日数的13%。秋季,我国近海海域呈明显降温过程,北部海域的降温幅度明显大于南部海域,受连续北上影响我国北部海域的热带气旋活动影响,9月黄海东部及东海东部的海面温度较气候态明显偏低。 相似文献
15.
Lin Xuechun 《海洋学报(英文版)》1990,9(4):527-538
In this paper, the response of the atmospheric 3-5 year cycle to Northern Pacific SST is discussed, The results are as follows:1. From the simultaneous temporal correlations between the Equatorial Eastern Pacific SST, the westerly dirft area's SST and the Northern Pacific SST at all gridpoints, we find that there are three correlative regions in the Northern Pacific SST field, they are the westerly drift area, the Equatorial Eastern Pacific and the Alaska Bay , and their structures are very similar to the PNA pattern in the atmosphere The difference PTI between the Equatorial Eastern Pacific SST anomaly and the westerly drift area's SST anomaly can indicate the change of the PNA pattern of the Northern Pacific SST anomaly. It can represent SST change of 65 % areas over the Northern Pacific and can keep watch on El Nino and un-El Nino.2. Simultaneous temporal correlative field between PTI and filtered 500hPa (there is 3-5 year cycle only ) of the Northern Hemisphere presents clear PNA structure. The resp 相似文献
16.
通过海气耦合模式CCSM3(The Community Climate System Model version 3),研究在北大西洋高纬度淡水强迫下,北太平洋冬季的海表温度SST、风场及流场的响应及其区域性差异。结果表明:淡水的注入使北太平洋整体变冷,但有部分区域异常增暖;在太平洋东部赤道两侧,SST的变化出现北负南正的偶极子型分布。阿留申低压北移的同时中纬度西风减弱,热带附近东北信风增强。黑潮和南赤道流减弱,北太平洋副热带逆流和北赤道流增强,日本海被南向流控制。风场及流场的改变共同导致了北太平洋SST异常出现复杂的空间差异:北太平洋中高纬度SST的降温主要由大气过程决定,海洋动力过程主要影响黑潮、日本海及副热带逆流区域的SST,太平洋热带地区SST异常由大气与海洋共同主导。 相似文献
17.
18.
S. K. Haslett 《Marine Ecology》1995,16(4):273-281
Abstract. Spongaster tetras tetras Ehrenberg has long been considered by palaeontologists as a species indicative of warm (>21 C) sea-surface temperatures (SSTs) and tropical/subtropical conditions. However. a comparison of the Plio-Pleistocene record of S. t. tetras in the eastern equatorial Pacific (Ocean Drilling Program Hole 677A) with CaCO3 , δ18 O, and δ13 C records reveals that S. t. tetras is most commonly present during periods of intense upwelling, often coinciding with isotopically identified glacial stages. when surface productivity and salinity are high, and SST is expected to be relatively low. Maximum S. t. tetras abundance (1.8% of radiolaria counted) occurred during a cool interglacial. when productivity and salinity were high, wind-driven upwelling intense, and SST relatively warmer than during glacial maxima. It appears that in the eastern equatorial Pacific upwelling system, SSTs are generally too cold (<21 C) for S. t. tetras to survive; however, S. t. tetras can tolerate (with populations <0.7%) cold SSTs if productivity and salinity are increased (due to upwelling), and flourishes (>0.7–> 1.8%) if this is coupled with relatively warm SSTs. This micropalaeontological study Corroborates the findings of an earlier research program on living S. t. tetras cultures (Anderson et al ., 1989a.b, c). 相似文献
19.
20.
本文通过对2004年西北太平洋热带气旋发生源地、月频数、移动路径、强度等方面的分析,找出2004年西北太平洋热带气旋的特征,并对其大气环流场进行了分析,结果表明:2004年西北太平洋热带气旋偏多、偏强,路径以近、远海转向为多,前期赤道东太平洋海温偏低、西太平洋副高位置偏北、偏东,是2004年西北太平洋热带气旋偏多的主要原因。 相似文献