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1.
An Observational Analysis of the Oceanic and Atmospheric Structure of Global-Scale Multi-decadal Variability简 总被引：5，自引：0，他引：5
The aim of the present study was to identify multi-decadal variability （MDV） relative to the current centennial global warming trend in available observation data.The centennial global wanning trend was first identified in the global mean surface temperature （STgm） data.The MDV was identified based on three sets of climate variables,including sea surface temperature （SST）,ocean temperature from the surface to 700 m,and the NCEP and ERA40 reanalysis datasets,respectively.All variables were detrended and low-pass filtered.Through three independent EOF analyses of the filtered variables,all results consistently showed two dominant modes,with their respective temporal variability resembling the Pacific Decadal Oscillation/Inter-decadal Pacific Oscillation （PDO/IPO） and the Atlantic Multi-decadal Oscillation （AMO）.The spatial structure of the PDO-like oscillation is characterized by an ENSO-like structure and hemispheric symmetric features.The structure associated with the AMO-like oscillation exhibits hemispheric asymmetric features with anomalous warm air over Eurasia and warm SST in the Atlantic and Pacific basin north of 10°S,and cold SST over the southern oceans.The Pacific and Atlantic MDV in upper-ocean temperature suggest that they are mutually linked.We also found that the PDO-like and AMO-like oscillations are almost equally important in global-scale MDV by EOF analyses.In the period 1975-2005,the evolution of the two oscillations has given rise to strong temperature trends and has contributed almost half of the STgm warming.Hereon,in the next decade,the two oscillations are expected to slow down the global warming trends. 相似文献
2.
ABSTRACTHistorical variability in sea surface temperature (SST) in the North Atlantic (NA) is examined using trend and Empirical Orthogonal Function (EOF) analyses of annual and summer means from three interpolated monthly datasets: Hadley Centre Sea Ice and Sea Surface Temperature (HadISST1), Extended Reconstruction of SST (ERSST), and Centennial in situ Observation-Based Estimates (COBE). Comparisons with time series of upper-ocean temperature from four monitoring sites off Atlantic Canada reveal substantial similarity in the interannual to multi-decadal variability but notable differences in the longer-term trends. The magnitude of decadal-scale variability is comparable to, or greater than, the long-term changes in all of the datasets; together with the trend discrepancies, this needs to be considered in climate change applications. Averaged over the NA, the annual means have a long-term increasing trend and a pronounced multi-decadal variation, resembling those in global mean (land-ocean) surface temperature and the Atlantic Multi-decadal Oscillation (AMO). There is remarkable similarity in the spatial and temporal variability of the three leading EOF modes from the different gridded datasets, with the first highly correlated with the AMO, the second modestly correlated with the winter North Atlantic Oscillation, and the third apparently related to ocean circulation variability. Trends since 1981 are generally two to three times larger than those since 1900 and 1950, which is at least partly related to the phase of the AMO. Trends in the summer means are generally larger than in the annual means. Overall, the results provide support for both anthropogenic global warming and decadal-scale natural variations making important contributions to ocean climate variability in the Northwest Atlantic. 相似文献
3.
The monthly mean sea surface temperature data of 6 areas are used to study the El Nino/Southern Oscillation signals in the global tropical ocean. These areas are in the 5oN-5oS latitude zone at 1) eastern Pacific (110o-l40oW), 2) western Atlantic (30o-50oW), 3) eastern Atlantic (10oW-10oE), 4) western Indian Ocean (30o-50oE), 5) central Indian Ocean (70o-90oE) and 6) far western Pacific (120o-140oE), and the data cover the 120-month period of December 1968 to November 1978.A power spectrum analysts shows that the characteristic time of the El Nino/Southern Oscillation (about 3-4 years) appears not only in the eastern Pacific but also in other areas of the tropics except for the western Pa-cific, where the spectrum is of white noise. The amplitude of oscillation in the eastern Pacific is about 4 times larger than the others, making the El Nino/Southern Oscillation signal the strongest in this area. According to a cross-spectrum analysis, there is no time lag between the variation in the central Indian Ocean and that in the eastern Pacific. These two areas oscillate simultaneously and comprise the main feature of the El Nino/ Southern Oscillation. Other tropical areas are related with time lags, as shown by correlation and coherence calculations.It should be noted that the sea surface temperature in the eastern Pacific oscillates in phase with that in the Indian Ocean, while the pressure oscillations in these two areas are out of phase with each other, according to the Southern Oscillation definition. It is suggested that the Southern Oscillation cannot be explained simply by the sea surface temperature anomalies.Variations in the far western equatorial Pacific do not have the time scale of the El Nino/Southern Oscilla-tion, perhaps because it is a buffer zone between the monsoon system and the trade wind system. 相似文献
4.
Previous studies suggested that there are large discrepancies in the intensity trend of the zonally averaged Hadley circulation (ZAHC) among different reanalyses. As the land, ocean, and topography are not evenly distributed, the ZAHC may mask the regional variability. Changes in the regional HC have important implications for regional climate change. Here, we detect the long-term trend of the boreal spring regional Hadley circulation intensity over the western Pacific (WPHC) since 1979 in both hemispheres using six reanalysis datasets. Unlike the ZAHC, we find that the trend of the spring WPHC intensity is consistent among various reanalysis datasets. All reanalyses show pronounced strengthening trends for the WPHC in both the Northern and Southern Hemisphere, which may be partly attributable to the robust warming trends of sea surface temperature in the tropical western Pacific. The result could improve our understanding of Hadley circulation variability at the regional scale and has implications for regional climate changes. 相似文献
5.
长江梅雨的长期变率与海洋的关系及其可预报性研究 总被引：4，自引：0，他引：4
采用最新发布的梅雨国家标准资料,以长江区域梅雨为代表,在分析区域梅雨的多时间尺度变化特征的基础上,从海洋外强迫影响因子角度探讨了梅雨的可预报性来源,进一步综合海洋背景变率和预测模型回报试验讨论梅雨异常的可预报性。结果表明:（1）长江梅雨呈现周期为3-4、6-8、12-16、32、64 a的多时间尺度变化分量和长期减少趋势。其中,3-4 a准周期变化是梅雨异常变化的主要分量。梅雨的干湿位相转变受12-16 a的准周期变化调制,极端涝年易出现在12-16 a准周期变化湿位相和3-4 a变化分量峰值位相叠加的情况。（2）长江梅雨的各准周期变化分量有不同的海洋外强迫背景,是梅雨可预报性的重要来源。与时间尺度较短的年际变化分量相关联的海温关键区主要分布于热带,而与时间尺度较长的年代际或多年代际变化分量相联系的海温关键区则来自中高纬度。3-4 a准周期变化分量的海洋外强迫强信号随季节变化由前冬的ENSO（厄尔尼诺-南方涛动）转为春末夏初的印度洋偶极子（IOD）。6-8和12-16 a年准周期变化分量的海洋强迫关键区主要位于太平洋。准32和准64 a周期振荡则受北太平洋多年代际变化（PDO）和北大西洋多年代际变化（AMO）的共同影响。梅雨的长期变化趋势则与全球变暖背景及以PDO为代表的年代际海洋外强迫因子相联系。（3）尽管梅雨异常与ENSO的正相关关系呈现减弱趋势,但20世纪70年代以后的梅雨异常年际变化分量的可预报性有所增大。（4）将梅雨各变化分量作为预测对象分别建模,进一步构建梅雨异常预测统计模型。采用该模型对近5年梅雨预测进行独立样本检验,有较好的回报效果,验证了梅雨异常年际分量可预报性的稳定性以及基于多时间尺度分离建立梅雨预测模型的优越性。 相似文献
6.
Variability and decline in the number of severe tropical cyclones making land-fall over eastern Australia since the late nineteenth century 总被引：2，自引：0，他引：2
Recent studies have raised concerns that tropical cyclones (TCs), particularly severe TCs, have become more frequent in many places in response to global warming. Other studies discuss errors in TC data that can cause large inaccuracies in some of the observed trends. Additional studies conclude that TCs are likely to become more intense in the future in response to global warming, while regional modelling studies for the south-west Pacific near north-eastern Australia project an intensification of TCs and either a decrease or no change in TC numbers. Here we describe and use a new data base of severe land-falling TCs for eastern Australia derived from numerous historical sources, that has taken over a decade to develop. It provides one of the world??s longest reliable records of tropical cyclone activity, and allows us to document changes over much longer periods than has been done previously for the Southern Hemisphere. Land-fall numbers are shown to vary a great deal on interannual, decadal and longer time-scales. The interannual variability is consistent with previous studies using much shorter data sets: land-fall numbers are well-simulated as a Poisson process and are modulated by the El Ni?o-Southern Oscillation (ENSO). Land-falls occurred almost twice as often in La Ni?a years as they did in El Ni?o years, and multiple land-falls only occurred during La Ni?a years. The statistical link between land-falls and pre-season values of the Southern Oscillation Index provides a modest predictive capability. Decadal variability in ENSO drives some of the decadal variability in land-fall numbers. The sign and magnitude of trends calculated over 30?years periods vary substantially, highlighting that caution needs to be taken in making inferences about trends based on e.g. satellite era data only. The linear trend in the number of severe TCs making land-fall over eastern Australia declined from about 0.45 TCs/year in the early 1870s to about 0.17 TCs/year in recent times??a 62% decline. This decline can be partially explained by a weakening of the Walker Circulation, and a natural shift towards a more El Ni?o-dominated era. The extent to which global warming might be also be partially responsible for the decline in land-falls??if it is at all??is unknown. 相似文献
7.
The internal climate variability of HadCM3, a version of the Hadley Centre coupled model without flux adjustments 总被引：3，自引：8，他引：3
We examine the internal climate variability of a 1000?year long integration of the third version of the Hadley Centre coupled model (HadCM3). The model requires no flux adjustment, needs no spin up procedure prior to coupling and has a stable climate in the global mean. The principal aims are (1) to validate the internal climate variability against observed climate variability, (2) to examine the model for any periodic modes of variability, (3) to use the model estimate of internal climate variability to asses the probability of occurrence of observed trends in climate variables, and (4) to compare HadCM3 with the previous version of the Hadley Centre model, HadCM2. The magnitude and frequency characteristics of the variability of the global mean surface temperature of HadCM3 on annual to decadal time scales is in good agreement with the observations. Observed upward trends in temperature over the last 20?years and longer are inconsistent with the internal variability of the model. The simulated spatial pattern of surface temperature variability is qualitatively similar to that observed, although there is an overestimation of the land temperature variability and regional errors in ocean temperature variability. The model simulates an El Niño Southern Oscillation with an irregular 3–4?year cycle, and with a teleconnection pattern which is much more like the observations than was found in HadCM2. The interdecadal variability of the model ocean in the tropical Pacific, North Pacific and North Atlantic is broadly similar to that in the real world with none of the simulated patterns having any periodic behaviour. HadCM3 simulates an Arctic Oscillation/North Atlantic Oscillation (NAO) in Northern Hemisphere winter which has a spatial pattern consistent with the observations in the Atlantic region, but has too much teleconnection with the North Pacific. The recent observed upward trend in the NAO index is inconsistent with the model internal variability. The variability of the simulated zonal mean atmospheric temperature shows some marked differences to the observed zonal mean temperature variability, although the comparison is confounded by the sparse observational network and its possible contamination by a climate change signal. 相似文献
8.
热带太平洋对全球的气候有重要作用。然而,关于全球变暖背景下热带太平洋海温长期趋势的研究,迄今为止仍有争议。本文利用多套海表温度资料和次表层海温资料,基于无参的趋势估计方法（Theil-Sen趋势）,分析了热带太平洋海表温度长期趋势及赤道太平洋次表层海温长期趋势。多套资料的结果均表明在全球变暖背景下,热带太平洋冷舌区为长期冷趋势,而冷舌区之外的热带太平洋区域为长期暖趋势,即似La Ni?a（La Ni?a-like）海温长期趋势。此海温长期趋势是由热带太平洋冷舌模态所引起。当冷舌模态为正位相时,对应热带太平洋冷舌区为冷海温异常,而冷舌区之外的热带太平洋为暖海温异常。冷舌模态时间序列主要为长期趋势,而造成冷舌模态长期趋势的机制是全球变暖强迫下的海洋动力反馈过程。赤道太平洋的表层和次表层海温似La Ni?a型的长期趋势,是冷舌模态在表层海温和次表层海温上的不同体现。 相似文献
9.
基于多套全球海温再分析数据和2种线性趋势分析方法,评估了1958-2014年中国近海海表温度（SST）的变化及其对全球气候变化的响应特征,并与全球平均地表温度特别是与若干重要海区的SST做了比较。研究表明：在全球变暖的显著加速期（1980年代和1990年代）,中国近海区域年平均SST表现出更快速的升温特征,其速率达0.60℃/10a,是同期全球平均升温速率的5倍以上;在变暖暂缓期（1998-2014年）,中国近海SST出现显著的下降趋势。研究还表明,中国近海区域SST的年代际变化与太平洋年代际涛动（PDO）的位相转换一致,前者SST的快速上升（下降）期与PDO正（负）位相最大值的时期相对应,PDO可能是通过东亚季风和黑潮影响中国近海SST的年代际变化。 相似文献
10.
A high-quality monthly pan evaporation dataset of 60 stations has been developed for monitoring long-term pan evaporation
trends over Australia. The quality control process involved examination of historical station metadata together with an objective
test comparing candidate series with neighboring stations. Identified points of discontinuity were located, including installations
of bird guards, site relocations and changes in exposure. Appropriate inhomogeneity adjustments have been applied using established
methods to produce the first homogeneous pan evaporation dataset for Australia. Analysis of these data reveals that Australian
annual mean pan-evaporation shows large interannual variability with no trend over the 1970–2005 period. Previous studies
using unadjusted data have shown a decline in pan evaporation, highlighting the importance of checking data for homogeneity
before drawing conclusions about long-term trends. A strong inverse correlation is evident between all-Australian means of
pan evaporation and rainfall, while a moderate positive correlation is found between pan evaporation and mean temperature.
The positive correlations between mean temperature and pan evaporation that exist on the interannual time scales are not reflected
in the long-term trends, highlighting that the mechanisms that are responsible for variations on the short and longer time
scales are different. This result cautions against the expectation that large changes in potential evaporation are a natural
consequence of global warming. 相似文献
11.
近百年全球地表月气温数据的概况与初步整合 总被引：2，自引：0，他引：2
基于国际上最著名的4套全球地表月气温数据集,即英国东安格利亚大学气候研究所数据集（CRUTEM3）、美国国家气候数据中心数据集（GHCN-V3）、美国国家航天航空局数据集（GISSTMP）和Berkeley地球表面气温数据集,从分析现有资源的状况入手,通过广泛的国际调研与合作,整合了这4套全球地表逐月气温数据集和一些主要国家或地区的区域数据集,研发了中国第一套全球陆地表面逐月气温站点数据集。该数据集共包含全球9519站、7073站及6587站的月平均气温、最高及最低气温（序列长度不低于20年）数据,同CRUTEM3和GHCN-V3数据集相比,该数据集站点密度在各个区域都有所增加,尤其是在南美洲、非洲及亚洲地区;另外,1990年代以来的站点数量显著增加,有利于降低自1990年以来全球气温变化趋势估计的不确定性。 相似文献
12.
20世纪全球增暖最显著的区域 总被引：6，自引：0，他引：6
Having analyzed a global grid temperature anomaly data set and some sea level pressure data during the last century, we found the following facts. Firstly, the annual temperature change with a warming trend of about 0.6℃/100 years in the tropical area over Indian to the western Pacific Oceans was most closely correlated to the global mean change. Therefore, the temperature change in this area might serve as an indicator of global mean change at annual and longer time scales. Secondly, a cooling of about -0.3℃ / 100 years occurred over the northern Atlantic. Thirdly, a two-wave pattern of temperature change, warming over northern Asia and northwestern America and cooling over the northern Atlantic and the northern Pacific, occurred during the last half century linked to strengthening westerlies over the northern Atlantic and the weakening Siberian High. Fourthly, a remarkable seasonal difference occurred over the Eurasian continent, with cooling (warming) in winter (summer) during 1896-1945, and warming (cooling) in winter (summer) during 1946-1995. The corresponding variations of the North Atlantic Oscillation and the Southern Oscillation were also discussed. 相似文献
13.
大气环流的年代际变化I.观测资料的分析 总被引：20，自引：1，他引：19
利用多种资料分析研究了大气环流(包括几个主要大气涛动、一些主要大气环流系统)的时间变化特征.结果清楚地表明大气环流,无论是热带大气还是中高纬度的大气环流,存在着显著的年代际变化特征,主要为10～20年准周期振荡和30多年准周期振荡.北大西洋涛动(NAO)和北太平洋涛动(NPO)的10～20年准周期振荡有近乎同位相特征,而它们的30多年准周期振荡却有近乎反位相变化.西太平洋副高强度与北美大槽强度的变化在10～20年时间尺度既有同位相情况也有反位相情况;但在30多年时间尺度却是基本同位相的.西太平洋副高强度与东亚大槽强度变化在30多年时间尺度也是基本同位相的,且副高变化超前约5～7年. 相似文献
14.
Annually averaged global mean land air temperature and sea surface temperature (SST) combined, and global mean SST alone share similar fluctuations. We examine contributions by modes of SST variability in the global mean SST based on a new version (version 3) of global sea-ice and SST (GISST3). Besides a trend mode, the dominant modes are El Niño-Southern Oscillation (ENSO), interhemispheric oscillation, and North Pacific oscillation. Statistics over the period of 1880–1997 show that excluding a warming trend the fluctuation on interannual (IA) and decadal-interdecadal (DID) time scales is dominated by IA ENSO and DID ENSO-like variability. However, the contribution by IA ENSO cycles experiences significant fluctuations, and there appears to be strong modulations by ENSO-like variability on DID or longer time scales: during several decade-long periods, when DID ENSO-like variability raises the temperature in the equatorial eastern Pacific, the contribution by IA ENSO cycles weakens to an insignificant level. The latest example of such modulation is the period since about 1980; despite the exceptional strength of El Niño events, the contribution by IA ENSO cycles weakens, suggesting that the exceptional strength is a consequence of superposition of IA El Niño events, a warming phase of DID ENSO-like variability, and possibly an ENSO-like warming trend. 相似文献
15.
Javier López-de-Lacalle 《Climate Dynamics》2012,38(11-12):2131-2141
Time series of seasonal temperatures recorded in Alaska during the past eighty years are analyzed. A common practice to measure changes in the long-term pattern of temperature series is to fit a deterministic linear trend. A deterministic trend is not a realistic approach and poses some pitfalls from the statistical point of view. A statistical model to fit a latent time-varying level independent of the Pacific climate shift is proposed. The empirical distribution of temperature conditional on the phase of the Pacific Decadal Oscillation is obtained. The results reveal that the switch between the negative and the positive phase leads to differences in temperatures up to 4°C in a given location and season. Differences across seasons and locations are detected. The effect of the Pacific climate shift is stronger in winter. An overall increase of temperatures is observed in the long term. The estimated trends are not constant but exhibit different patterns that vary in the sign and strength over the sample period. 相似文献
16.
Summary This paper is to promote a further understanding of the interdecadal variations of the summer monsoon rainfall over South
China (SCMR). With this focus, we will specifically aim at better understanding possible mechanism responsible for such an
interdecadal variation relationship between the SCMR and El Ni?o/Southern Oscillation (ENSO). In many of the previous studies
on precipitation, the datasets used are satellite observations or gridded reanalyzed data due to the lack of long-term reliable
observations over the marginal seas of the Asian continent. Such an approach could lead to possible errors in the results.
In this work, several representative stations with long-term rain-gauge observations are chosen to reduce such uncertainty.
The study of the interdecadal variabilities of SCMR indicates that there is a strong linkage between SCMR and ENSO on the
interdecadal variations. These results agree well with those from previous studies that the Pacific Decadal Oscillation (PDO)
and ENSO are not independent of each other, the interannual and interdecadal variations of tropical Pacific Sea Surface temperatures
(SSTs) could affect the interdecadal variations of the SCMR, and the incorporating information on the PDO/ENSO could improve
the long-term prediction of the SCMR. 相似文献
17.
A 10,000-year long simulation has been made with the CSIRO Mark 2 coupled global atmospheric-oceanic model for present climatic conditions. The annual mean output from the model has been used to calculate global distributions of climatic trends. These trends were derived by linear regression using a least squares fit to a given climatic time series for a selected trend duration. Typically, this information cannot be obtained from the limited observational record, hence the simulation provides a documentation of many climatic trend characteristics not previously available. A brief examination of observed climatic trends is given to demonstrate the viability of the trend analysis. This is followed by a range of global trend distributions for various climatic variables and trend durations. At any one time only relatively small regions of the globe have trends significant at the 95% level. Markedly different trend patterns occur for a given trend duration computed for different times within the simulation. Decadal and multi-decadal trend patterns revealed consistent relationships for El Niño/Southern Oscillation (ENSO)-related climatic variables. It was found that within a given duration trend, noticeable shorter term counter-trends can exist, with the latter being much stronger. In general, a strong trend is indicative of a short duration, thus highlighting the danger of extrapolating such trends. Examination of time series of climatic trends emphasised the dominance of decadal variability and the essential residual nature of, especially longer term, trends. Rainfall trends over Australia are used to indicate the almost continent-wide changes that can occur in trend patterns within a few decades, in agreement with observation. The outcome emphasises that any changes in current, observed climatic trends should not automatically be attributed to greenhouse forcing. Importantly, it is noted that for conditions associated with naturally occurring climatic variability, the global mean of any climatic trend distribution should be zero or near zero. Departures from this situation imply the existence of an external forcing agency. Thousand year trends could be readily identified within the simulation, but the variations from millennium to millennium indicate the occurrence of secular variability. A probability density function distribution of 30-year duration trends within a selected millennium revealed a near-Gaussian outcome. This, together with other analyses, supports the conclusion that stochastic processes dominate the climatic variability within the simulation. 相似文献
18.
Lisa J. Graumlich Michael F. J. Pisaric Lindsey A. Waggoner Jeremy S. Littell John C. King 《Climatic change》2003,59(1-2):245-262
Climate variability, coupled with increasing demand is raising concerns about the sustainability of water resources in the western United States. Tree-ring reconstructions of stream flow that extend the observational record by several centuries provide critical information on the short-term variability and multi-decadal trends in water resources. In this study, precipitation sensitive Douglas-fir (Pseudotsuga menzeisii) tree ringrecords are used to reconstruct annual flow of the Yellowstone River back to A.D. 1706. Linkages between precipitation in the Greater Yellowstone Region and climate variability in the Pacific basin were incorporated into our model by including indices Pacific Ocean interannual and decadal-scale climatic variability, namely the Pacific Decadal Oscillation and the Southern Oscillation. The reconstruction indicates that 20th century streamflow is not representative of flow during the previous two centuries. With the exception of the 1930s, streamflow during the 20th century exceeded average flows during the previous 200 years. The drought of the 1930s resulted in the lowest flows during the last three centuries, however, this probably does not represent a worst-case scenario for the Yellowstone as other climate reconstructions indicate more extreme droughts prior to the 18th century. 相似文献
19.
A fully coupled ocean-atmosphere model is applied to highlight the mechanism of the long-term variability (including decadal and longer time scales) in the Pacific Ocean. We are interested in the effect of ocean-atmosphere coupling of different regions during these processes. The control run successfully simulates the Pacific long-term variability, whose leading modes are the Pacific (inter) Decadal Oscillation (PDO) and the North Pacific mode (NPM). Furthermore, three numerical experiments are conducted, s... 相似文献
20.
《大气与海洋》2013,51(3):277-296
Abstract Sea level responses to climatic variability (CV) and change (CC) signals at multiple temporal scales (interdecadal to monthly) are statistically examined using long‐term water level records from Prince Rupert (PR) on the north coast of British Columbia. Analysis of observed sea level data from PR, the longest available record in the region, indicates an annual average mean sea level (MSL) trend of +1.4±0.6 mm yr?1 for the period (1939–2003), as opposed to the longer term trend of 1±0.4 mm yr?1 (1909–2003). This suggests a possible acceleration in MSL trends during the latter half of the twentieth century. According to the results of this study, the causes behind this acceleration can be attributed not only to the effects of global warming but also to cyclic climate variability patterns such as the strong positive Pacific Decadal Oscillation (PDO) phase that has been present since the mid‐1970s. The linear regression model based on highest sea levels (MAXSL) of each calendar year showed a trend exceeding twice that (3.4 mm yr?1) of MSL. Previous work shows that the influence of vertical crustal motions on relative sea level are negligible at PR. Relations between sea levels and known CV indices (e.g., the Multivariate ENSO Index (MEI), PDO, Northern Oscillation Index (NOI), and Aleutian Low Pressure Index (ALPI)) are explored to identify potential controls of CV phenomena (e.g., the El Niño Southern Oscillation (ENSO), PDO) on regional MSL and MAXSL. Linear and non‐linear statistical methods including correlation analyses, multiple regression, Cumulative Sum (CumSum) analysis, and Superposed Epoch Analysis (SEA) are used. Results suggest that ENSO forcing (as shown by the MEI and NOI indices) exerts significant influence on winter sea level fluctuations, while the PDO dominates summer sea level variability. The observational evidence at PR also shows that, during the period 1939–2003, these cyclic shorter temporal scale sea level fluctuations in response to CV were significantly greater than the longer term sea‐level rise trend by as much as an order of magnitude and with trends over twice that of MSL. Such extreme sea level fluctuations related to CV events should be the immediate priority for the development of coastal adaptation strategies, as they are superimposed on long‐term MSL trends, resulting in greater hazard than longer term MSL rise trends alone. 相似文献