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1.
In this study, interannual variability of summer rainfall over the northern part of China (NPC) and associated circulation patterns were investigated by using long-term (1961–2013) observational and reanalysis data. Two important NPC rainfall modes were identified by empirical orthogonal function analysis: the first is characterized by an almost uniformly distributed rainfall anomaly over most parts of the NPC, while the second shows rainfall variability in Northeast China (NEC) and its out-of-phase relationship with that in North China (NC) and the northern part of Northwest China. The results also suggest that the NPC summer rainfall anomalies are also closely associated with those in some other parts of China.It is revealed that the circumglobal teleconnection pattern associated with the anomalous Indian summer monsoon (ISM) and the Polar/Eurasia (PEA) pattern work in concert to constitute the typical circulation pattern of the first rainfall mode. The cooperative engagement of the anomalous ISM circulation and the PEA pattern is fundamental in transporting water vapor to the NPC. The study emphasizes that the PEA pattern is essential for the water vapor transport to the NPC through the anomalous midlatitude westerly.In the second NPC rainfall mode, the typical circulation pattern is characterized by the anomalous surface Okhotsk high and the attendant lower tropospheric circulation anomaly over NEC. The circulation anomaly over NEC leads to a redistribution of water vapor fluxes over the NPC and constitutes an out-of-phase relationship between the rainfall anomalies over NEC and NC. 相似文献
2.
《大气与海洋》2012,50(4):295-306
ABSTRACTSummer precipitation in the northern China monsoon region (NCMR; 35°–55°N, 108°–135°E) shows significant intraseasonal variability. The early-summer (June) and late-summer (July–August) precipitation patterns show clear differences in their formation mechanisms and the systems that affect them. We used empirical orthogonal function (EOF) analysis to investigate the two leading modes of July–August precipitation over the NCMR and their associated atmospheric circulation anomalies using linear regression. The results show that the first (EOF1) and second (EOF2) modes correspond to a pan-NCMR precipitation variation pattern and a precipitation oscillation pattern between North China (NC) and Northeast China (NEC), respectively. These two modes account for 22.1% and 10.1% of the total variance, respectively. The associated principal components (PCs) both have significant interannual variability with a period of 2–4 years. In addition, PC1 has significant interdecadal variability with a period of 20–30 years. Further analysis suggests that EOF1 and EOF2 clearly have a different relationship with the summer monsoon circulation system. In the positive phase of PC1, the East Asian subtropical westerly jet stream (EAWJS) shows a northward trend with higher intensity than normal the blocking high at mid- to high latitudes is inactive; and the western Pacific subtropical high (WPSH) is located to the north of its normal position. The NCMR is controlled by stronger southerly winds, which cause the convergence of water vapour, favouring more precipitation in this region and vice versa. In the positive phase of PC2, the EAWJS swings to the south of Lake Baikal. Significant positive height anomalies exist from western NC to NEC. Significant negative height anomalies occur to the subtropical northwestern Pacific. This indicates that the cold vortex in Northeast China is inactive, the WPSH tends to be weaker and located to the south of its normal position, and NEC (NC) is dominated by anomalous northeasterly (southeasterly) winds. The convergence (divergence) of water vapour in NC (NEC) favours more (less) precipitation in NC (NEC) and vice versa. Therefore, EOF1 is related to the large-scale circulation anomalies over East Asia and the northwest Pacific in July and August, whereas EOF2 is more closely related to the anomalies in the regional circulation over the NCMR and the subtropical northwestern Pacific. 相似文献
3.
The strength of the East Asian summer monsoon and associated rainfall has been linked to the western North Pacific subtropical high (WNPSH) and the lower-tropospheric low pressure system over continental East Asia (EA). In contrast to the large number of studies devoted to the WNPSH, little is known about the variability of the East Asian continental low. The present study delineates the East Asian continental low using 850-hPa geopotential height. Since the low is centered over northern EA (NEA), we refer to it as the NEA low (NEAL). We show that the intensity of the NEAL has large interannual variation, with a dominant period of 2–4 years. An enhanced NEAL exhibits a barotropic structure throughout the whole troposphere, which accelerates the summer-mean upper-tropospheric westerly jet and lower-tropospheric monsoon westerly to its south. We carefully identify the anomalous NEAL-induced rainfall anomalies by removal of the tropical heating effects. An enhanced NEAL not only increases rainfall locally in northern Northeast China, but also shifts the East Asian subtropical front northward, causing above-normal rainfall extending eastward from the Huai River valley across central-northern Japan and below-normal rainfall in South China. The northward shift of the East Asian subtropical front is attributed to the following processes without change in the WNPSH: an enhanced NEAL increases meridional pressure gradients and the monsoon westerly along the East Asian subtropical front, which in turn induces a cyclonic shear vorticity anomaly to its northern side. The associated Ekman pumping induces moisture flux convergence that shifts the East Asian subtropical front northward. In addition, the frequent occurrence of synoptic cut-off lows is found to be associated with an enhanced NEAL. Wave activity analysis indicates that the interannual intensity change of the NEAL is significantly associated with the extratropical Polar Eurasian teleconnection, in addition to the forcing of the tropical WNP heating. 相似文献
4.
本文基于中国地面气温日值网格数据集（V2.0）,采用滑动相关和相关分析等方法,揭示了冬季北大西洋涛动（NAO）对中国北方极端低温影响的事实,进一步证实了东北后冬（1、2月）冷日（夜）与同期NAO相关性的年代际变化。研究发现:在20世纪80年代中期前,东北后冬冷日（夜）频发,与NAO的相关性较好,而在80年代中期后东北后冬冷日（夜）少发,与NAO的相关性减弱。其中,1月在1969~1988阶段,东北冷日（夜）与NAO的相关性最好,相关区域显著,相关系数可达-0.68（-0.66）,而在1989~2009阶段二者相关性最弱,相关区域不显著。进一步分析发现,在不同年代际背景下,NAO引起的大气环流异常是导致东北1月冷日（夜）与1月NAO相关性年代际变化的重要原因。相关性较好的年代,NAO引起的环流异常有利于冷涡等天气系统维持在贝加尔湖到东北一带,使东北地区气温偏低,冷日（夜）频发;相关性较弱的年代,不利于冷空气南下,使东北地区气温偏高,冷日（夜）少发。 相似文献
5.
This study documents the first two principal modes of interannual variability of midsummer precipitation over Northeast China(NEC) and their associated atmospheric circulation anomalies. It is shown that the first principal mode exhibits the largest amount of variability in precipitation over the south of NEC(referred to as the south mode), whereas the second principal mode behaves with the greatest precipitation anomaly over the north of NEC(referred to as the north mode). Further findings reveal that, through modulating moisture transportation and upper-and lower-troposphere divergence circulation as well as vertical movement over NEC, the anomalous northwestern Pacific anticyclone and the anticyclone centered over northern NEC exert the dominant influence on the south and north modes, respectively. Additionally, it is quantitatively estimated that water vapor across the southern boundary of NEC dominates the moisture budget for the south mode, while the north mode has a close connection with moisture through NEC's northern and western boundaries. Furthermore, the north(south) mode is strongly related to the intensity(meridional shift) of the East Asian westerly jet. 相似文献
6.
Based on daily precipitation data, the spatial-temporal features of heavy rainfall events (HREs) during 1960-2009 are investigated. The results indicate that the HREs experienced strong decadal variability in the past 50 years, and the decadal features varied across regions. More HRE days are observed in the 1960s, 1980s, and 1990s over Northeast China (NEC); in the 1960s, 1970s, and 1990s over North China (NC); in the early 1960s, 1980s, and 2000s over the Huaihe River basin (HR); in the 1970s-1990s over the mid-lower reaches of the Yangtze River valley (YR); and in the 1970s and 1990s over South China (SC). These decadal changes of HRE days in eastern China are closely associated with the decadal variations of water content and stratification stability of the local atmosphere. The intensity of HREs in each sub-region is also characterized by strong decadal variability. The HRE intensity and frequency co-vary on the long-term trend, and show consistent variability over NEC, NC, and YR, but inconsistent variability over SC and HR. Further analysis of the relationships between the annual rainfall and HRE frequency as well as intensity indicates that the HRE frequency is the major contributor to the total rainfall variability in eastern China, while the HRE intensity shows only relative weak contribution. 相似文献
7.
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8.
Subodh K. Saha Subhadeep Halder K. Krishna Kumar B. N. Goswami 《Climate Dynamics》2011,36(11-12):2077-2089
It is proposed that, land?Catmosphere interaction around the time of monsoon onset could modulate the first episode of climatological intraseasonal oscillation (CISO) and may generate significant ??internal?? interannual variation in the Indian summer monsoon rainfall. The regional climate model RegCM3 is used over Indian monsoon domain for 27?years of control simulation. In order to prove the hypothesis, another two sets of experiment are performed using two different boundary conditions (El Ni?o year and non-ENSO year). In each of these experiments, a single year of boundary conditions are used repeatedly year after year to generate ??internal?? interannual monsoon variability. Simulation of monsoon climate in the control model run is found to be in reasonably good agreement with observation. However, large rainfall bias is seen over Arabian Sea and Bay of Bengal. The interannual monsoon rainfall variability are of the same order in two experiments, which suggest that the external influences may not be important on the generation of ??internal?? monsoon rainfall variability. It is shown that, a dry (wet) pre-onset land-surface condition increases (decreases) rainfall in June which in turn leads to an anomalous increase (decrease) in seasonal (JJAS) rainfall. The phase and amplitude of CISO are modulated during May?CJune and beyond that the modulation of CISO is quite negligible. Though the pre-onset rainfall is unpredictable, significant modulation of the post-onset monsoon rainfall by it can be exploited to improve predictive skill within the monsoon season. 相似文献
9.
Spatial and Temporal Variations of Rainfall over Northern Asia in the Last 100 Years and Their Possible Changes in the Future 
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下载免费PDF全文 The reliability of CRU05 rainfall dataset produced by Climatic Research Unit, University of East Anglia is examined against 22 station observations in the northern China. While this dataset has high spatial resolution and long temporal coverage, comparison with station data suggests that it only has higher quality in the last 70 years in the western China. When using this dataset to analyze rainfall variability over the northern China, significant oscillations with periods of 3, 10, and 30 yr are found, with interannual and interdecadal oscillations being the major characteristics of drought and flood events in the region in the
last 100 years. Using EOF and REOF analysis, 10 divisions with coherent rainfall variations have been identified, including (i) central Asia and north of Xinjiang, (ii) North China and east of Northwest China,(iii) north and middle of Mongolia, (iv) Hexi Corridor and west of Mongolia, (v)east of the Heilong River,(vi) north of Da Hinggan Mountains, (vii) north of Central Asia, (viii) south of Xinjiang and the Qinghai-Tibetan Plateau, (ix) south of Northeast China, and (x) north of Altay Mountains. Results suggest that the pronounced feature of drought in the arid and semi-arid areas of northern China is not isolated. Of course, it is consistent with rainfall variations in the arid areas of Mongolia and Central Asia. In addition,by analyzing prominent oscillations observed in the last several decades, the trends of rainfall variations over the region in the future 10-15 years are discussed. 相似文献
10.
Summary Along with averages, rainfall variability and distribution are important climatological information. In this study, using 114 years (1871–1984) data of 306 stations, it is demonstrated that the variability and spatial distribution of annual, summer monsoon and monthly rainfall are highly dependent upon the respective period mean rainfall variation over India. The magnitude of three selected absolute measures of variability, e.g. standard deviation, absolute mean deviation and mean absolute interannual variability is found to increase linearly with mean rainfall.In order to describe the relation between the rainfall frequency distribution and the mean rainfall, a linear regression between the rainfall amount expected with a specified exceedance/non-exceedance probability and the mean rainfall amount is presented. Highly significant linear curves for a large number of probabilities specified in an average probability diagram clearly demonstrate the dependence of the rainfall frequency distribution on mean rainfall over India.With 8 Figures 相似文献
11.
夏季中国华北与印度降水之间的关联及其成因分析 总被引：3，自引：2，他引：1
本文基于1951~2012年的再分析资料以及站点观测资料,针对中国华北夏季降水和印度夏季风降水的协同变化(正相关)关系,利用集合经验模态分解法(EEMD)对两个降水序列进行时间尺度分解,并在年际尺度上分别考察了对两者正相关关系形成的有利和不利环流形势.结果表明,印度夏季风降水和华北夏季降水序列的较好正相关关系主要来自周期为2~3年的年际尺度分量,两者在该时间尺度上的相关系数为0.34,达到99%的信度水平.在年际尺度上,与印度夏季风降水异常有关的对流层中高层环半球遥相关型(CGT)波列能够衔接伊朗高原和环渤海地区上空的同位相环流异常(反气旋式或气旋式),从而有利于华北夏季降水和印度夏季风降水之间的协同变化.然而,这一协同变化关系并不总是成立.当伊朗高原上空异常中心的位置偏西时,CGT波列无法形成.这时,即使印度夏季风降水出现显著异常,华北地区却易受东亚—太平洋型或西太平洋型遥相关型的影响而其降水形势可能与印度夏季风降水形势相反.这些结论有助于进一步理解印度夏季风降水与华北夏季降水的正相关关系,从而对华北夏季降水的预测具有参考意义. 相似文献
12.
LIN Zhongda 《大气科学进展》2014,31(6):1366-1376
East Asian summer climate is strongly affected by extratropical circulation disturbances.In this study,impacts of four atmospheric teleconnections over Eurasia on East Asian summer rainfall are investigated using National Centers for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR） reanalysis data and Climatic Research Unit （CRU） land precipitation data during 1979-2009.The four teleconnections include the Scandinavian （SCA）,the Polar/Eurasian （PEU）,the East Atlantic/Western Russian （EAWR）,and the circumglobal teleconnection （CGT）.Moreover,the related changes of lower-tropospheric circulation are explored,specifically,the low pressure over northern East Asia （NEAL） and the subtropical high over the western North Pacific （WNPSH）.The results presented are in the positive phase.The PEU and SCA induce significant negative anomalies in North China rainfall （NCR）,while the CGT induces significant positive anomalies.In the past three decades,the PEU and SCA explain more than 20％ of the variance in NCR,twice that explained by the CGT,suggesting a more important role of the former two teleconnections in NCR variation than the latter one.Meanwhile,the PEU and SCA reduce rainfall in Northeast China and South Korea,respectively,and the CGT enhances rainfall in Japan.The rainfall responses are attributed to the SCA-induced northward shift of the NEAL,and PEU-induced northward shift and weakening of the NEAL,respectively.For the CGT,the dipole pattern of rainfall anomalies between North China and Japan is affected by both westward extension of the NEAL and northwestward expansion of the WNPSH.In addition,the EAWR leads to an increase of sporadic rainfall in South China as a result of the eastward retreat of the WNPSH. 相似文献
13.
Spatial and temporal variability of summer rainfall over Ethiopia from observations and a regional climate model experiment 总被引：2，自引：1，他引：1
T. Zeleke F. Giorgi G. Mengistu Tsidu G. T. Diro 《Theoretical and Applied Climatology》2013,111(3-4):665-681
The spatial and temporal variability of rainfall over Ethiopia during the summer (JJAS) season is studied using observations (both station and satellite based) and model simulation data. The simulation dataset is generated using the fourth version of the International Center for Theoretical Physics Regional Climate Model (RegCM4) for the period 1989–2005. Ethiopia is first divided into 12 homogeneous regions using criteria including rotated empirical orthogonal function (REOF), spatial correlation, seasonal cycles, and topographical features. Spatially averaged observed and simulated rainfall time series are then generated and analyzed for each region. Standardized rainfall anomalies of the observations and the simulated data are highly correlated over the northern, western, northeastern, central, and southwestern regions, while a weak correlation is found over the border regions of the country. The dominant modes of rainfall variability are identified using REOF, while time–frequency variations of different dominant modes are described by wavelet analysis. The first leading patterns of rainfall and upper wind (averaged between 100 and 300 hPa) are highly correlated and exhibit similar features between simulation and observations over the northern, western, southwestern, and eastern regions of Ethiopia. The second loading pattern of rainfall and the first loading pattern of low-level wind (averaged between 850 and 1,000 hPa) exhibit a dipole structure across the southwestern and northeastern regions of the country. The dominant signals in the first rotated principal component (RPC) of rainfall and upper level wind fields show a period of 4–5 and 2–3 years, while the dominant signals in the second RPC show a period of 2–3 years at a 0.05 significance level. The correlations of significant RPCs across gauge, gridded, and model rainfall fields with that of low and upper level winds show the presence of a significant relationship (correlation exceeding ～0.6). Overall, the RegCM4 shows a good performance in simulating the spatial and temporal variability of precipitation over Ethiopia. 相似文献
14.
采用1960~2012年5~6月中国东北地区实况降水资料,依据东北冷涡活动客观识别方法,研究东北冷涡活动对东北地区初夏降水的影响,结果表明:5~6月每次东北冷涡过程维持时间以3~7天为主,且具有频发特征,东北冷涡降水累计量占总降水量的62.5%,给出冷涡降水月强度指数,与同期月降水量年际变化具有很好一致性;东北地区初夏降水与东北冷涡降水EOF分解主要模态十分相近,前两个模态分别为全区一致和东北、西南降水相反分布,各占方差贡献的46.8%与42.7%。冷涡降水具有显著“累积效应”,该累计效应可总体反映初夏东北地区降水异常分布特征,进一步揭示东北冷涡活动的气候学特征。 相似文献
15.
冬季太平洋SSTA对北太平洋风暴轴年际变化的影响 总被引：6，自引：0，他引：6
研究了冬季北太平洋风暴轴的年际异常及其与500hPa高度以及热带和北太平洋海温的联系。结果发现，冬季北太平洋风暴轴中心有线性增强、偏北、偏东的趋势。对15个冬季北太平洋风暴轴区域 500 hPa天气尺度滤波位势高度方差与同期热带和北太平洋海温的 SVD分析表明，第一对空间典型分布反映了 ENSO区海温异常对风暴轴年际变化的影响，而第二对空间典型分布反映了黑潮区域海温异常对风暴轴年际变化的影响。进一步的合成分析显示，ENSO区海温异常可以通过激发500hPa高度场上的PNA遥相关型影响冬季北太平洋风暴轴的东西摆动和中、东端的强度变化，而黑潮区域海温异常则通过激发 500 hPa高度场上的 WP遥相关型，主要影响冬季北太平洋风暴轴中、西端的强度变化和南北位移。 相似文献
16.
近52年北上热带气旋的若干气候特征 总被引：5，自引：1，他引：5
应用1951-2002年热带气旋年鉴资料，对52年来北上热带气旋的月际变化、年际和年代际变化、气候突变、振荡周期等若干气候特征进行了分析。结果表明：北上热带气旋的月际变化特征明显，7—9月是北上热带气旋发生的关键月份，尤其7、8月是高峰期，1-4月和12月没有北上热带气旋。北上热带气旋的年际变化表现为略有上升的趋势，并以每10年3％的倾向率上升。用Mann-Kendall方法作突变分析，没有明显的突变年。近52年，北上热带气旋呈现出明显的年际和年代际变化特征，存在5年的显著年际周期，同时还存在10～12年、20-22年的年代际振荡周期。 相似文献
17.
Elsa Mohino Bel��n Rodr��guez-Fonseca Teresa Losada S��bastien Gervois Serge Janicot Juergen Bader Paolo Ruti Fabrice Chauvin 《Climate Dynamics》2011,37(9-10):1707-1725
Rainfall over West Africa shows strong interannual variability related to changes in Sea Surface Temperature (SST). Nevertheless, this relationship seem to be non-stationary. A particular turning point is the decade of the 1970s, which witnessed a number of changes in the climatic system, including the climate shift of the late 1970s. The first aim of this study is to explore the change in the interannual variability of West African rainfall after this shift. The analysis indicates that the dipolar features of the rainfall variability over this region, related to changes in the Atlantic SST, disappear after this period. Also, the Pacific SST variability has a higher correlation with Guinean rainfall in the recent period. The results suggest that the current relationship between the Atlantic and Pacific El Ni?o phenomena is the principal responsible for these changes. A fundamental goal of climate research is the development of models simulating a realistic current climate. For this reason, the second aim of this work is to test the performance of Atmospheric General Circulation models in simulating rainfall variability over West Africa. The models have been run with observed SSTs for the common period 1957?C1998 as part of an intercomparison exercise. The results show that the models are able to reproduce Guinean interannual variability, which is strongly related to SST variability in the Equatorial Atlantic. Nevertheless, problems in the simulation of the Sahelian interannual variability appear: not all models are able to reproduce the observed negative link between rainfall over the Sahel and El Ni?o-like anomalies in the Pacific, neither the positive correlation between Mediterranean SSTs and Sahelian rainfall. 相似文献
18.
Previous studies have indicated a connection between interannual variations of the Indian and North China summer rainfall. An atmospheric circulation wave pattern over the mid-latitude Asia plays an important role in the connection. The present study compares the influence of the above-normal and below-normal Indian summer rainfall on the North China summer rainfall variations. Composite analysis shows that the mid-latitude Asian atmospheric circulation and the North China rainfall anomalies during summer tend to be anti-symmetric in above-normal and below-normal Indian rainfall years. Analysis indicates that the Indian-North China summer rainfall relation tends to be stronger when larger Indian rainfall anomaly occurs during a higher mean rainfall period. The observed long-term change in the Indian-North China summer rainfall relationship cannot be explained by the impact of the El Niño-Southern Oscillation (ENSO). The present study evaluates the Indian-North China summer rainfall relationship in climate models. Analysis shows that the Indian-North China summer rainfall relationship differs largely among different climate models and among different simulations of a specific model. The relationship also displays obvious temporal variations in both individual and ensemble mean model simulations. This suggests an important role of the atmospheric internal variability in the change of the Indian-North China summer rainfall relationship. 相似文献
19.
East Asian (EA) summer monsoon shows considerable differences in the mean state and principal modes of interannual variation between early summer (May–June, MJ) and late summer (July–August, JA). The present study focuses on the early summer (MJ) precipitation variability. We find that the interannual variation of the MJ precipitation and the processes controlling the variation have been changed abruptly around the mid-1990s. The rainfall anomaly represented by the leading empirical orthogonal function has changed from a dipole-like pattern in pre-95 epoch (1979–1994) to a tripole-like pattern in post-95 epoch (1995–2010); the prevailing period of the corresponding principal component has also changed from 3–5 to 2–3 years. These changes are concurrent with the changes of the corresponding El Nino-Southern Oscillation (ENSO) evolutions. During the pre-95 epoch, the MJ EA rainfall anomaly is coupled to a slow decay of canonical ENSO events signified by an eastern Pacific warming, which induces a dipole rainfall feature over EA. On the other hand, during the post-95 epoch the anomalous MJ EA rainfall is significantly linked to a rapid decay of a central Pacific warming and a distinct tripolar sea surface temperature (SST) in North Atlantic. The central Pacific warming-induced Philippine Sea anticyclone induces an increased rainfall in southern China and decreased rainfall in central eastern China. The North Atlantic Oscillation-related tripolar North Atlantic SST anomaly induces a wave train that is responsible for the increase northern EA rainfall. Those two impacts form the tripole-like rainfall pattern over EA. Understanding such changes is important for improving seasonal to decadal predictions and long-term climate change in EA. 相似文献
20.
Variability of rainfall from tropical cyclones in the eastern USA and its association to the AMO and ENSO 总被引：1，自引：0，他引：1
Ricardo C. Nogueira Barry D. Keim David P. Brown Kevin D. Robbins 《Theoretical and Applied Climatology》2013,112(1-2):273-283
Tropical cyclone (TC) rainfall along the eastern USA exhibits a high degree of variability with the potential to produce precipitation amounts in excess of 100 % of the annual mean at locations ranging from the immediate coastline to hundreds of kilometers inland. However, the spatiotemporal distribution of TC rainfall variability has not yet been fully characterized for this region, particularly with regard to large-scale climate teleconnections (e.g., El Nino-Southern Oscillation (ENSO) and Atlantic multidecadal oscillation (AMO)). The objectives of this study are to (1) assess temporal variability and trends in TC rainfall since 1960, and (2) characterize the spatial variability of TC rainfall during varying AMO and ENSO regimes. Kendall tau-b analysis highlighted the presence of statistically significant positive trends in TC rainfall at a number of locations. Principal components analysis revealed that AMO exhibited significant linkages to TC rainfall in northern New England as well as along the US Gulf Coast, while ENSO was most strongly linked to TC variability in Texas. Results illustrate the varied nature of TC rainfall across the eastern USA and the complex linkages to large-scale climate mechanisms at interannual and decadal time scales. 相似文献