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1.
Extratropical cyclone variability in the Northern Hemisphere winter from the NCEP/NCAR reanalysis data 总被引：9，自引：0，他引：9
The winter climatology of Northern Hemisphere cyclone activity was derived from 6-hourly NCEP/NCAR reanalysis data for the
period from 1958 to 1999, using software which provides improved accuracy in cyclone identification in comparison to numerical
tracking schemes. Cyclone characteristics over the Kuroshio and Gulfstream are very different to those over continental North
America and the Arctic. Analysis of Northern Hemisphere cyclones shows secular and decadal-scale changes in cyclone frequency,
intensity, lifetime and deepening rates. The western Pacific and Atlantic are characterized by an increase in cyclone intensity
and deepening during the 42-year period, although the eastern Pacific and continental North America demonstrate opposite tendencies
in most cyclone characteristics. There is an increase of the number of cyclones in the Arctic and in the western Pacific and
a downward tendency over the Gulf Stream and subpolar Pacific. Decadal scale variability in cyclone activity over the Atlantic
and Pacific exhibits south-north dipole-like patterns. Atlantic and Pacific cyclone activity associated with the NAO and PNA
is analyzed. Atlantic cyclone frequency demonstrates a high correlation with NAO and reflects the NAO shift in the mid 1970s,
associated with considerable changes in European storm tracks. The PNA is largely linked to the eastern Pacific cyclone frequencies,
and controls cyclone activity over the Gulf region and the North American coast during the last two decades. Assessment of
the accuracy of the results and comparison with those derived using numerical algorithms, shows that biases inherent in numerical
procedures are not negligible.
Received: 7 July 2000 / Accepted: 30 November 2000 相似文献
2.
北半球温带气旋活动和风暴路径的年代际变化 总被引：12，自引：3，他引：9
基于欧洲中心再分析数据ERA40的海平面气压场和高度场,本文分别采用拉格朗日和欧拉方法研究分析了1958～2001年北半球的不同季节温带气旋活动和风暴路径的年代际变化,以及可能的原因.以客观判定和追踪温带气旋为基础的拉格朗日方法得到了北半球的两个温带气旋主要活动中心,即北太平洋地区和北大西洋/北美地区,同时以500 hPa位势高度天气尺度滤波方差为基础的欧拉方法得到了同主要气旋活动中心相吻合的两条风暴轴.研究表明,44年中北大西洋/北美地区温带气旋活动北移加强,以春季最为显著.风暴轴也同样存在着向极移动并加强的特征,并且温带气旋和风暴路径两者移动趋势的相关性很高.作为一个典型地区,北大西洋/北美地区的气旋活动体现了风暴路径的北移,以及温带地区向极地的扩展.但有意思的是北太平洋的情况完全不同,即北太平洋地区的温带气旋活动和风暴轴向低纬度偏移并加强,以春季的南移趋势最为显著.对于此结论,两种方法也有很高的统计相关性.虽然大量研究表明北半球整体上呈现出风暴路径北移的变化特征,但对于具体地区情况有明显差异.另外,400 hPa最大Eady增长率和气旋活动频率的经验正交展开函数 (EOF) 第一模态的空间分布和时间序列非常相似,北太平洋地区和北大西洋地区风暴路径相反的变化趋势很可能同其大气斜压性的同位相的变化有着密切的关系.这也从另一个方面支持了本文对温带气旋和风暴路径年代际变化的分析. 相似文献
3.
Changes of air–sea coupling in the North Atlantic Ocean over the 20 th century are investigated using reanalysis data,climate model simulations, and observational data. It is found that the ocean-to-atmosphere feedback over the North Atlantic is significantly intensified in the second half of the 20 th century. This coupled feedback is characterized by the association between the summer North Atlantic Horseshoe(NAH) SST anomalies and the following winter North Atlantic Oscillation(NAO). The intensification is likely associated with the enhancement of the North Atlantic storm tracks as well as the NAH SST anomalies. Our study also reveals that most IPCC AR4 climate models fail to capture the observed NAO/NAH coupled feedback. 相似文献
4.
5.
The secular trends and interannual variability of wintertime temperatures over northern extratropical lands and circulations over the northern hemisphere are examined using the NCEP/NCAR reanalysis from 1961 to 2010. A primitive equation dry atmospheric model, driven by time-averaged forcing in each winter diagnosed from the NCEP reanalysis, is then employed to investigate the influences of tropical and extratropical forcing on the temperature and circulation variability. The model has no topography and the forcing is thus model specific. The dynamic and thermodynamic maintenances of the circulation and temperature anomalies are also diagnosed. Distinct surface temperature trends over 1961–1990 and 1991–2010 are found over most of the extratropical lands. The trend is stronger in the last two decades than that before 1990, particularly over eastern Canadian Arctic, Greenland, and Asia. The exchange of midlatitude and polar air supports the temperature trends. Both the diagnosed extratropical and tropical forcings contribute to the temperature and circulation trends over 1961–1990, while the extratropical forcing dominates tropical forcing for the trends over 1991–2010. The contribution of the tropical forcing to the trends is sensitive to the period considered. The temperature and circulation responses to the diagnosed tropical and extratropical forcings are approximately additive and partially offsetting. Covariances between the interannual surface temperature and 500-hPa geopotential anomalies for the NCEP reanalysis from 1961 to 2010 are dominated by two leading modes associated with the North Atlantic Oscillation (NAO) and Pacific-North American (PNA) teleconnection patterns. The diagnosed extratropical forcing accounts for a significant part of the NAO and PNA associated variability, including the interannual variability of stationary wave anomalies, as well as dynamically and thermodynamically synoptic eddy feedbacks over the North Atlantic and North Pacific. The tropical forcing contributes to the PNA related temperature and circulation variability, but has a small contribution to the NAO associated variability. Additionally, relative contributions of tropical Indian and Pacific forcings are also assessed. 相似文献
6.
ERA40再分析资料揭示的北半球和东亚地区温带气旋生成频率变化 总被引：6，自引：0，他引：6
本文利用欧洲中心再分析数据ERA40的6小时间隔海平面气压场和一种改进的客观判定和追踪方法研究19582001年北半球和东亚地区温带气旋生成频率的气候态、年代际变化及可能原因。结果表明:(1)北半球温带气旋的源地主要位于北美东部(落基山下游地区)、西北大西洋地区、格陵兰至欧洲北部地区、蒙古地区和日本至西北太平洋地区。大洋的西岸和陡峭地形的背风坡有利于大气斜压性的增强和正涡度的发展,从而有利于地面气旋的形成。(2)年、冬季和春季30°～60°N气旋生成数目呈现减少的变化趋势,60°～90°N地区的气旋生成数呈增加的变化趋势。这在一定程度上支持了北半球风暴路径北移的观点。60°N以南和以北的温带气旋数目同北极涛动指数(AO)分别呈现负相关和正相关,这种相关性在年、春季和秋季最为显著。(3)1 958—2001年东亚地区的年气旋数目呈现明显的年代际变化。20世纪60年代至80年代中期40°～60°N、80°～140°E地区气旋数目呈增加趋势,而80年代中期之后温带气旋数目则锐减,主要原因是80年代以后该地区大气斜压性减弱,更高纬度地区的大气斜压性增强,从而导致了气旋源地的北移。在较低纬带的20°～40°N、110°～160°E地区气旋数目线性增加,这主要是由于位于40°～55°N的北太平洋风暴轴有向低纬度偏移的变化趋势造成的。 相似文献
7.
Large changes in the wintertime atmospheric circulation have occurred over the past two decades over the ocean basins of the Northern Hemisphere, and these changes have had a profound effect on regional distributions of surface temperature and precipitation. The changes over the North Pacific have been well documented and have contributed to increases in temperatures across Alaska and much of western North America and to decreases in sea surface temperatures over the central North Pacific. The variations over the North Atlantic are related to changes in the North Atlantic Oscillation (NAO). Over the past 130 years, the NAO has exhibited considerable variability at quasi-biennial and quasi-decadal time scales, and the latter have become especially pronounced the second half of this century. Since 1980, the NAO has tended to remain in one extreme phase and has accounted for a substantial part of the observed wintertime surface warming over Europe and downstream over Eurasia and cooling in the northwest Atlantic. Anomalies in precipitation, including dry wintertime conditions over southern Europe and the Mediterranean and wetter-than-normal conditions over northern Europe and Scandinavia since 1980, are also linked to the behavior of the NAO. Changes in the monthly mean flow over the Atlantic are accompanied by a northward shift in the storm tracks and associated synoptic eddy activity, and these changes help to reinforce and maintain the anomalous mean circulation in the upper troposphere. It is important that studies of trends in local climate records, such as those from high elevation sites, recognize the presence of strong regional patterns of change associated with phenomena like the NAO. 相似文献
8.
进入北极地区的气旋在移动过程中往往伴有大风、强降水等特征,对北极气候变化有深刻的影响。基于NCEP2再分析资料,识别并跟踪了北半球夏季(6—8月)从中纬度进入北极的温带气旋,考察了其年际变化特征和影响因素。结果表明:1979—2019年夏季进入北极的温带气旋共867个,其中消失在北极边缘区域和中心区域的数量分别为688个和161个,且后者平均强度更大、平均持续时间更长。分区域研究发现,夏季从陆地进入极区的气旋个数较多,而从海洋进入极区的气旋强度更大,活动更为剧烈。对进入北极的气旋年际时间序列进行分析发现,夏季进入北极的气旋个数和强度均存在年际变率,其中气旋个数的年际变率尤为显著。气旋个数年际变率主要周期为5 a,强度的主要周期约为2.7 a。进一步分析发现,引导气流是影响气旋向北移动的重要因素。此外,夏季北大西洋气旋强度与同期北大西洋涛动(North Atlantic Oscillation,NAO)指数存在较好相关。研究还表明,进入极区气旋活动的年际变化受大气斜压不稳定性的影响,在北太平洋地区区域平均的Eady增长率与气旋个数和强度的相关性均最强,相关系数分别为0.4和0.5。 相似文献
9.
N. A. Vyazilova 《Russian Meteorology and Hydrology》2012,37(7):431-437
Carried out is the comparative analysis of the cyclone activity for different combinations of positive and negative values of the North Atlantic Oscillation (NAO) and East Atlantic Oscillation (EA) indices. The integral characteristics of the cyclone activity (density and intensity of cyclones) are computed on the basis of the method of automatic indication of cyclone centers from the sea-level pressure data. It is demonstrated that the NAO index is really the major indicator of cyclone activity anomaly formation in the North Atlantic, however, the variations of cyclone activity in the European region, of the number of cyclones and their integral intensity are better characterized by the EA index. 相似文献
10.
Three-Dimensional Structure and Low-Level Features of the North Pacific Storm Track from 1999 to 2005 
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下载免费PDF全文 A storm track is a region in which synoptic eddy activities are statistically most prevalent and intense. At daily weather charts, it roughly corresponds to the mean trajectories of cyclones and anticyclones. In this paper, the recent QuikSCAT （Quick Scatterometer） satellite sea winds data with a 0.5°×0.5° horizontal resolution, and the NCEP （National Centers for Environmental Prediction） 10-m height Gaussian grid wind data and pressure-level reanalysis data, are employed to document the spatial structure of the North Pacific storm track in winter （January） and summer （July） from 1999 to 2005. The results show that in winter the North Pacific storm track is stronger, and is located in lower latitudes with a distinct zonal distribution. In summer, it is weaker, and is located in higher latitudes. Based on the horizontal distributions of geopotential height variance at various levels, three-dimensional schematic diagrams of the North Pacific storm track in winter and summer are extracted and presented. Analyses of the QuikSCAT wind data indicate that this dataset can depict the low-level storm track features in detail. The double storm tracks over the Southern Oceans found by Nakamura and Shimpo are confirmed. More significantly, two new pairs of low-level storm tracks over the North Pacific and the North Atlantic are identified by using this high-resolution dataset. The pair over the North Pacific is focused in this paper, and is named as the ＂subtropical storm track＂ and the ＂subpolar storm track＂, respectively. Moreover, statistical analyses of cyclone and anticyclone trajectories in the winters of 1999 to 2005 reveal as well the existence of the low-level double storm tracks over the North Pacific. 相似文献
11.
北太平洋风暴轴的三维空间结构 总被引：9，自引：1，他引：8
文中利用最新的0.5°×0.5°分辨率QuikSCAT(QuikBird Satellite Microwave Scatterometer Sea Winds Data)海面风场资料、NCEP(National Center for Environmental Prediction)的10 m高度风场资料和全球客观再分析资料,对1999-2005年冬季(1月)和夏季(7月)北太平洋风暴轴的三维空间结构进行了分析,发现冬季北太平洋风暴轴的强度较强,呈明显的纬向拉伸带状分布特征,位置偏南.夏季北太平洋风暴轴的强度较弱,位置偏北.根据不同高度上位势高度方差的水平分布特征,绘制了北太平洋风暴轴的三维结构示意图.利用高分辨率QuikSCAT资料对风暴轴特征的刻画更为细致,不但验证了Nakamu-ra在南大洋发现的双风暴轴现象,而且还发现在北太平洋和北大西洋下层分别存在"副热带风暴轴"和"副极地风暴轴"两个风暴轴.对1999-2005年冬季北太平洋气旋和反气旋的移动路径进行的统计分析,为北太平洋"双风暴轴"的存在提供了强有力的证据. 相似文献
12.
The surface boundary conditions are altered in a numerical simulation of January climate by prescribing (a) higher and (b)
lower than average snow extent over Northern Hemisphere land masses. The anomalies in snow cover are shown to have quite a
strong impact on the mean climatic state. Associated with an increase in the areal extent of the snow, there is a significant
reduction in temperature throughout the lower troposphere. There are also large increases in sea-level pressure over most
land areas. Significant responses in the mass field are also seen at 500 hPa where reductions in atmospheric thickness lead
to significant negative anomalies in the height field. Responses are also seen non-locally, over both the North Pacific and
North Atlantic basins. The impact of increased snow on cyclone tracks is also examined. A reduction in cyclones is noted over
both continents and over the western sectors of both ocean basins. Over the North Atlantic basin this reduction extends across
over Europe, significantly weakening the storm track. In the North Pacific, cyclone density is reduced in the west while in
the east, there is actually a strengthening of the storm tracks. There are corresponding changes in the genesis of cyclones
in both of these regions. The change in cyclogenesis, intensity and density is demonstrated to be associated with changes
in baroclinicity between the two experiments. The anomalous snow boundary conditions lead to significant changes in the meridional
temperature gradients over both ocean basins which impact on the baroclinic zones.
Received: 5 January 1996 / Accepted: 4 May 1996 相似文献
13.
The present paper selects the northern winter of December 1995–February 1996 for a case study on the impact of sea surface temperature (SST) anomalies on the atmospheric circulation over the North Atlantic and Western Europe. In the Atlantic, the selected winter was characterized by positive SST anomalies over the northern subtropics and east of Newfoundland, and negative anomalies along the US coast. A weak La Niña event developed in the Pacific. The North Atlantic Oscillation (NAO) index was low, precipitation over the Iberian Peninsula and northern Africa was anomalously high, and precipitation over northern Europe was anomalously low. The method of study consists of assessing the sensitivity of ensemble simulations by the UCLA atmospheric general circulation model (UCLA AGCM) to SST anomalies from the observation, which are prescribed either in the World Oceans, the Atlantic Ocean only, or the subtropical North Atlantic only. The results obtained are compared with a control run that uses global, time-varying climatological SST. The ensemble simulations with global and Atlantic-only SST anomalies both produce results that resemble the observations over the North Atlantic and Western Europe. It is suggested that the anomalous behavior of the atmosphere in the selected winter over those regions, therefore, was primarily determined by conditions within the Atlantic basin. The simulated fields in the tropical North Atlantic show anomalous upward motion and lower (upper) level convergence (divergence) in the atmosphere overlying the positive SST anomalies. Consistently, the subtropical jet intensifies and its core moves equatorward, and precipitation increases over northern Africa and southern Europe. The results also suggest that the SST anomalies in the tropical North Atlantic only do not suffice to produce the atmospheric anomalies observed in the basin during the selected winter. The extratropical SST anomalies would provide a key contribution through increased transient eddy activity, which causes an extension of the subtropical jet eastward from the coast of North America. 相似文献
14.
The variable link between PNA and NAO in observations and in multi-century CGCM simulations 总被引：1，自引：1，他引：0
The link between the Pacific/North American pattern (PNA) and the North Atlantic Oscillation (NAO) is investigated in reanalysis data (NCEP, ERA40) and multi-century CGCM runs for present day climate using three versions of the ECHAM model. PNA and NAO patterns and indices are determined via rotated principal component analysis on monthly mean 500?hPa geopotential height fields using the varimax criteria. On average, the multi-century CGCM simulations show a significant anti-correlation between PNA and NAO. Further, multi-decadal periods with significantly enhanced (high anti-correlation, active phase) or weakened (low correlations, inactive phase) coupling are found in all CGCMs. In the simulated active phases, the storm track activity near Newfoundland has a stronger link with the PNA variability than during the inactive phases. On average, the reanalysis datasets show no significant anti-correlation between PNA and NAO indices, but during the sub-period 1973?C1994 a significant anti-correlation is detected, suggesting that the present climate could correspond to an inactive period as detected in the CGCMs. An analysis of possible physical mechanisms suggests that the link between the patterns is established by the baroclinic waves forming the North Atlantic storm track. The geopotential height anomalies associated with negative PNA phases induce an increased advection of warm and moist air from the Gulf of Mexico and cold air from Canada. Both types of advection contribute to increase baroclinicity over eastern North America and also to increase the low level latent heat content of the warm air masses. Thus, growth conditions for eddies at the entrance of the North Atlantic storm track are enhanced. Considering the average temporal development during winter for the CGCM, results show an enhanced Newfoundland storm track maximum in the early winter for negative PNA, followed by a downstream enhancement of the Atlantic storm track in the subsequent months. In active (passive) phases, this seasonal development is enhanced (suppressed). As the storm track over the central and eastern Atlantic is closely related to the NAO variability, this development can be explained by the shift of the NAO index to more positive values. 相似文献
15.
Cyclone Phase Space Characteristics of the Extratropical Transitioning Tropical Cyclones over the Western North Pacific 总被引：2，自引：0，他引：2 下载免费PDF全文
下载免费PDF全文 The cyclone phase space (CPS) method has been utilized to evaluate the extratropical transition (ET) of tropical cyclones
(TCs) in many recent publications. However, these studies mainly focused over the North Atlantic basin. In this paper, the
CPS characteristics of all the cyclones over the western North Pacific are investigated and discussed, with three parameters
calculated from the best-track data of the Regional Specialized Meteorological Center in Tokyo and the Japanese 25-yr reanalysis
data. It is concluded that most TCs over the western North Pacific possess the non-frontal and warm-core structure, while
a larger number of cyclones that have undergone ET hold the frontal and cold-core structure. The spatial pattern of the CPS
parameters indicates that the areas of tropical and extratropical cyclone activities could be demarcated by 30°N. The composite
and individual series of three parameters of the CPS indicate that the transformation of −V
TU from positive to negative leads to the start of ET, and could be considered as a potential predictor in operationally forecasting
an ET event. 相似文献
16.
春季北大西洋三极型海温异常变化及其与NAO和ENSO的联系 总被引：1，自引：0，他引：1
利用1951—2016年HadISST逐月海表温度(Sea Surface Temperature,SST)资料,NCEP/NCAR再分析资料以及1958—2016年美国伍兹霍尔海洋研究所(Woods Hole Oceanographic Institution,WHOI)提供的OAFlux数据集,运用经验正交函数分解(Empirical Orthogonal Function,EOF)和偏相关分析等统计方法,研究了春季北大西洋海温异常的主要特征及其与春季NAO和前期冬季ENSO联系。结果表明:春季北大西洋海温异常EOF的第一模态是自北而南出现的三极结构的海温距平型,其方差贡献率为35.7%。春季北大西洋三极型海温异常的形成主要受到春季NAO主导作用,还受到前期冬季热带中东太平洋海温异常的影响。消除前期冬季Niňo3.4的影响后,春季北大西洋三极型海温异常指数与同期北大西洋涛动(North Atlantic Oscillation,NAO)指数的偏相关系数分别为0.50,通过了99%置信度水平的显著性检验。消除春季NAO的影响后,春季北大西洋三极型海温异常指数与前期冬季Niňo3.4指数的偏相关系数为-0.26,通过了95%信度水平的显著性检验。春季NAO正(负)位相引起的海表风场和海表湍流热通量的异常,进而激发出正(负)位相的北大西洋三极型海温异常。前期冬季ENSO事件可以引起春季大气环流异常和热带外海温异常,进而调制春季NAO对北大西洋三极型海温异常的影响。 相似文献
17.
Huang Ruping Chen Shangfeng Chen Wen Yu Bin Hu Peng Ying Jun Wu Qiaoyan 《Climate Dynamics》2021,56(11):3643-3664
Compared to the zonal-mean Hadley cell (HC), our knowledge of the characteristics, influence factors and associated climate anomalies of the regional HC remains quite limited. Here, we examine interannual variability of the northern poleward HC edge over western Pacific (WPHCE) during boreal winter. Results suggest that interannual variability of the WPHCE is impacted by the El Niño-Southern Oscillation (ENSO) Modoki, North Pacific Oscillation (NPO) and North Atlantic Oscillation (NAO). The WPHCE tends to shift poleward during negative phase of the ENSO Modoki, and positive phases of the NPO and NAO, which highlights not merely the tropical forcing but also the extratropical signals that modulate the WPHCE. ENSO modoki, NPO and NAO modulate the WPHCE via inducing atmospheric anomalies over the western North Pacific. We further investigate the climatic impacts of the WPHCE on East Asia. The poleward shift of the northern descending branch of the WPHC results in anomalous upward (downward) motions and upper-level divergence (convergence) anomalies over south-central China (northern East-Asia), leading to increased (decreased) rainfall there. Moreover, pronounced cold surface air temperature anomalies appear over south-central China when the sinking branch of the WPHC moves poleward. Based on the temperature diagnostic analysis, negative surface temperature tendency anomalies over central China are mostly attributable to the cold zonal temperature advection and ascent-induced adiabatic cooling, while the negative anomalies over South China are largely due to the cold meridional temperature advection. These findings could improve our knowledge of the WPHCE variability and enrich the knowledge of forcing factors for East Asian winter climate.
相似文献18.
本文利用1975—1984年12—2月北太平洋爆发性温带气旋资料以及500 hPa天气图，概括出气旋爆发式加强前12小时五种环流型，即北美高压型（NAH）、东太平洋高压型（EPH）、中太平洋高压型（MPH）、白令海阻高型（BBH）、太平洋低压型（PL）。以NAH型和EPH型出现的机会最多，稳定时间最长，并且在这两种天气形势下气旋最易发展。另外本文还分析了气旋爆发后的路径趋势，指出在形势稳定期，气旋爆发后的路径亦稳定；在形势调整期，气旋后期路径随太平洋长波系统的演变而变化。 相似文献
19.
Long-term precipitation variability in Morocco and the link to the large-scale circulation in recent and future climates 总被引：1，自引：0，他引：1
Summary ?Monthly precipitation data from the Global Historical Climatology Network for 42 stations in Morocco and its vicinity are
investigated with respect to baroclinicity, storm track and cyclone activity, moisture transports, North Atlantic Oscillation
(NAO) variations, and different circulation types by means of correlation and composite studies. The results are related to
a climate change scenario from an ECHAM4/OPYC3 transient greenhouse gas only (GHG) simulation. Precipitation in northwestern
Morocco shows a clear link to the baroclinic activity over the North Atlantic during boreal winter (DJF). In large precipitation
months the North Atlantic storm track is shifted southward, more westerly and northwesterly circulation situations occur and
moisture transports from the Atlantic are enhanced. The occurrence of local cyclones and upper-level troughs is more frequent
than in low precipitation months. The negative correlation to the NAO is relatively strong, especially with Gibraltar as a
southern pole (−0.71). The northward shift of the storm track and eastward shift of the Azores High predicted by the ECHAM
model for increasing GHG concentrations would therefore be associated with decreasing precipitation and potentially serious
impacts for the future water supply for parts of Morocco. In the region south of the Atlas mountains, moisture transports
from the Atlantic along the southern flank of the Atlas Mountains associated with cyclones west of Morocco and the Iberian
Peninsula can be identified as a decisive factor for precipitation. Northeastern Morocco and Northwestern Algeria, however,
is rather dominated by the influence of cyclones over the Western Mediterranean that are associated with a strong northwesterly
moisture transport. As both regions appear to be less dependent on the North Atlantic storm track and more on local processes,
a straight forward interpretation of the large-scale changes predicted by the ECHAM4/OPYC3 cannot be done without the application
of down-scaling methods in the future.
Received July 19, 2001; revised May 31, 2002 相似文献
20.
本文利用1951—1980年逐季的平均值资料(共120个季)讨论了北方涛动和与其相联系的北太平洋海温与北半球海平面气压场、500hPa位势高度场遥相关的基本结构,并与南方涛动和赤道东太平洋海温的结果进行了对比分析.发现北太平洋Namias海区和加利福尼亚海流区海温的变化与北方涛动具有很密切的联系;北方涛动和这两个海区的海温同北半球中高纬度大气环流特别是PNA型和NAO型环流异常存在明显的遥相关关系;南方涛动和赤道太平洋海温同WP型或NPO型环流异常关系比较密切,而与PNA型和NAO型的关系不如北方涛动和Namias海区及加利福尼亚海流区海温的显著. 相似文献