共查询到18条相似文献，搜索用时 118 毫秒
1.
北大西洋涛动和北极涛动与新疆河川径流变化 总被引：4，自引：2，他引：2
分析了冬季北大西洋涛动(NAO)和北极涛动(AO)与新疆天山南北不同流域河川径流变化的关系.结果表明:影响北半球气温、降水等气候驱动因子的NAO和AO同样与新疆河川径流的变化具有显著的遥相关.在年际变化上,NAO和AO的强弱分别与径流变化的相关性具有明显的区域性差异;在年代际尺度上,NAO和AO有超前于新疆河流年径流5 a的显著相关,相关关系分别超过了95%和99%置信水平.NAO和AO变化对预测新疆河川径流的变化有很好的实际意义. 相似文献
2.
ENSO(厄尔尼诺-南方涛动)事件的发生会影响区域气候变化。通过对青海东部地区5个站点1959~2005年的降水、气温资料、干燥度和海表温度距平(SSTA)与南方涛动指数(SOI)的月序列进行相关性分析和周期性谱分析,探讨了区域气候变化与ENSO事件的关系。结果表明,1959~2005年青海省东部地区气候趋于暖干,并且冬春季变化趋势显著;暖事件的发生对该区域降水、气温及干燥度的变化影响较大,且气温对ENSO事件的响应要大于降水;ENSO事件对该区域的气候变化有两到三个月的影响期,EI Nino事件的发生对当月的影响较大,而La Nina事件的发生对该区域有两到三个月的持续影响期;降水距平及气温距平与ENSO事件存在短期相同的变化趋势,且该地区气候变化受南方涛动影响明显。 相似文献
3.
基于SPEI指数的兰州干旱特征与气候指数的关系 总被引：2，自引：0，他引：2
基于1961~2012年逐日气象及同期4个气候因子资料系列,采用标准化降水蒸散发指数(SPEI)定量描述兰州地区干旱状况,利用M-K检验分析了该地干旱变化趋势,采用皮尔逊相关系数法以及交叉小波变换法研究了SPEI与北大西洋涛动(NAO)、北极振荡(AO)、太平洋十年涛动(PDO)以及厄尔尼诺-南方涛动(ENSO)四个气候因子之间的关系。研究结果表明:干旱指数SPEI在月、春、夏、秋及年尺度上均呈显著下降趋势、冬季增长趋势不显著,未来兰州春、夏和秋季缺水有加重趋势,冬季有变湿润倾向;SPEI与PDO、ENSO在秋季呈显著负相关;ENSO主要影响干旱短周期的年际变化;干旱与PDO和AO呈滞后的负相关关系,两指数主要影响较长周期干旱的年际和年代际变化。 相似文献
4.
环青海湖地区气候变化特征及其季风环流因素 总被引：1，自引：0，他引：1
基于青海湖流域及其周边地区11个气象站点1959—2015年逐月气温和降水数据,采用Mann-Kendall趋势分析、突变分析、Morlet连续小波变换、Pearson相关分析和R/S分析等方法,分析了平均气温、平均最高气温、平均最低气温和降水的年、季变化特征及其季风环流影响因素,并探讨了该区域未来气候变化的总体趋势。研究结果表明:(1)环青海湖地区气温和降水总体上呈现出显著增加的趋势,秋季和冬季的平均气温、平均最高气温和平均最低气温上升速率以及夏季和冬季降水增加速率最为明显。(2)气温和降水均存在较为明显的突变现象,气温突变时间普遍在1986年左右,而降水突变时间在2002年左右;研究区气温普遍存在2~3年的短周期,8~10年和30~32年的中长周期变化,而降水则存在着3~4年、6~7年的短周期和30~32年的长周期变化。(3)东亚夏季风指数对研究区秋季气温和夏季降水具有较大的影响,而印度夏季风主要影响了研究区春季气温和降水;北极涛动指数(AO)对研究区秋季和冬季气温的上升影响最大,对春季、夏季和冬季降水的影响也明显高于其他指数;北大西洋涛动指数(NAO)和厄尔尼诺—南方涛动(ENSO)对研究区气温影响较小,NAO主要影响夏季和冬季降水,而ENSO主要影响秋季降水。(4)研究区年均气温和年降水的Hurst指数均大于0.5,说明研究区气温和降水在未来一段时间内仍以上升趋势为主。 相似文献
5.
基于雅砻江流域及邻近地区28个地面气象站点资料,在不同时空尺度采用降水探测评价指标评价了多源降水再分析产品——中国区域高时空分辨率地面气象要素驱动数据集(CMFD)中的降水资料,全球降水计划多卫星集成降水产品(GPM-IMERG)和多源加权融合降水产品(MSWEP)三种降水产品在研究区的适用情况。结果表明:虽然CMFD在湿季和年尺度研究区有极轻微的低估现象,但在各时间尺度表现均优于IMERG和MSWEP;在日、月、年和湿季尺度,三者精度同纬度和高程成正比,在干季,纬度高海拔地区精度较中低纬度和中低海拔地区低;CMFD和IMERG精度随月、年、湿季、干季和日尺度的顺序降低;而MSWEP精度随月、年、干季、湿季和日尺度的顺序降低;IMERG在湿季、MSWEP在干季表现较好,在月尺度二者表现相近;CMFD探测不同量级雨量能力最高,MSWEP和IMERG分别次之;随着降水数量的增加,各数据集探测能力均变弱。研究结果为研究区水文气象工作提供借鉴。 相似文献
6.
在全球气候变暖背景下,青藏高原东南缘的川滇横断山高海拔地区秋冬季温度变化已经成为区域气候变化研究热点。为了更好地了解长时间尺度下秋冬季平均气温变化对树木生长的影响,本文运用泸沽湖地区丽江云杉(Picea likiangensis)树轮宽度资料,建立了标准年表。并基于气温与树轮宽度指数的关系,重建了过去137年来川西南地区的秋冬季平均气温波动历史。重建序列存在2个暖期(1911~1927 A.D.,1992~2015 A.D.)、1个冷期(1939~1991 A.D.)。与其他树轮序列、沉积记录及历史记录的比较和空间相关分析,显示重建结果可靠,且具有区域代表性。集合经验模态(EEMD)分解得到2 a、19 a和54 a的周期控制序列冷暖波动。厄尔尼诺-南方涛动(ENSO),太阳黑子,太平洋年代际涛动(PDO)和北大西洋涛动(NAO)可能是以上周期的驱动因子. 相似文献
7.
为明确珠江流域雨季特征及ENSO(El Ni?o-Southern Oscillation)对雨季降雨的影响,利用多尺度滑动T检验法划分了珠江流域雨季,阐明CPW(Central Pacific Warming)、EPC(Eastern Pacific Cooling)、EPW(Eastern Pacific Warming)、传统ENSO和ENSO Modoki五种ENSO类型在发展期和衰减期对珠江流域雨季降雨产生的影响及其物理归因。研究结果表明：在EPC发展期和衰减期,珠江流域的雨季降雨显著减小;ENSO和ENSO Modoki在发展期更容易引发洪涝,而衰减期更容易引起干旱;更强的印度洋季风和北太平洋西部的反气旋会为珠江流域雨季带来更多的降雨。 相似文献
8.
《地球科学进展》2016,(11)
20世纪90年代中后期北大西洋涛动(NAO)年代际变率的发现与北极涛动(AO)概念的提出,引发了持续至今的古AO/NAO研究热潮。从观测和模拟两方面对多时间尺度的古AO/NAO研究进展做了系统的回顾与总结,包括近千年AO/NAO序列的重建,全新世AO/NAO变化趋势的争议,末次冰盛期AO/NAO振幅的减弱,末次间冰期AO/NAO的异常偏正,以及AO/NAO的气候平均态与振幅2个关键概念的区分。其中对不同时段AO/NAO的变化机理做了简要概括与讨论。在此基础上,建议在今后的古AO/NAO研究中,除了寻找时间更长、与AO/NAO显著相关的代用资料外,还要着力加强气候模拟方面的工作,特别是长时间瞬变模拟及对关键外强迫因子开展敏感性试验。只有将观测与数值模拟相结合,才可进一步增进对AO/NAO与气候背景间动力机制的理解。在过去20年间,气候学界对AO/NAO的广泛研究,对于理解全球变暖背景下AO/NAO的变化过程、并提高其可预报性都具有重要意义。 相似文献
9.
分析了1961—2010年黄河源的水文气象要素的演变过程。由于丰水期（7月、 8月、 9月）降水减少而温度升高, 导致黄河源年径流及降水总体上呈非显著减少趋势, 且1990年代以来9月份秋季洪峰消失。以30年为一个时间窗口, 使用偏相关方法, 分别计算了黄河源丰水期的降水、 径流与WCI（西风指数）、 ENSO（厄尔尼诺-南方涛动）和IOD（印度洋偶极子）的偏相关关系并排除了ENSO、 IOD与WCI之间的共同作用, 发现WCI对黄河源丰水期径流影响要高于ENSO与IOD, WCI的增强可能是黄河源8月降水减少及9月洪峰消减的主要因素。 相似文献
10.
北大西洋涛动对青藏高原夏季降水的影响 总被引：4，自引：2，他引：2
利用青藏高原中东部1961-2004年60个气象台站夏季(6-8月)降水资料,通过旋转经验正交函数分解发现青藏高原夏季降水存在南北反向变化的空间模态,分析表明这种变化模态与北大西洋涛动(NAO)密切相关.利用NCEP/NCAR再分析资料进行环流场分析,探讨了NAO对青藏高原这种降水空间变化模态的影响机制.结果表明:强NAO年份时,高原北部水汽输送通量强度增强,水汽辐合增强,而高原南部水汽输送通量强度减弱,此时高原切变线位置明显偏北,正是在这种水汽输送和环流形式配置下使得高原北部降水偏多而高原南部降水偏少;在弱NAO年份,上述情况基本相反. 相似文献
11.
Relations between climatic variability and hydrologic time series from four alluvial basins across the southwestern United States 总被引：1，自引：3，他引：1
Hydrologic time series of groundwater levels, streamflow, precipitation, and tree-ring indices from four alluvial basins in the southwestern United States were spectrally analyzed, and then frequency components were reconstructed to isolate variability due to climatic variations on four time scales. Reconstructed components (RCs), from each time series, were compared to climatic indices like the Pacific Decadal Oscillation (PDO), North American Monsoon (NAM), and El Niño-Southern Oscillation (ENSO), to reveal that as much as 80% of RC variation can be correlated with climate variations on corresponding time scales. In most cases, the hydrologic RCs lag behind the climate indices by 1–36 months. In all four basins, PDO-like components were the largest contributors to cyclic hydrologic variability. Generally, California time series have more variation associated with PDO and ENSO than the Arizona series, and Arizona basins have more variation associated with NAM. ENSO cycles were present in all four basins but were the largest relative contributors in southeastern Arizona. Groundwater levels show a wide range of climate responses that can be correlated from well to well in the various basins, with climate responses found in unconfined and confined aquifers from pumping centers to mountain fronts. 相似文献
12.
Freshwater delivery is an important factor determining estuarine character and health and may be influenced by large-scale climate oscillations. Variability in freshwater delivery (precipitation and discharge) to the Altamaha River estuary (GA, USA) was examined in relation to indices for several climate signals: the Bermuda High Index (BHI), the Southern Oscillation Index (SOI), the Improved El Niño Modoki Index (IEMI), the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO), the Pacific Decadal Oscillation (PDO), and the Pacific/North American Pattern (PNA). Discharge to this estuary has been linked to key ecosystem properties (e.g., salinity regime, water residence time, nutrient inputs, and marsh processes), so understanding how climate patterns affect precipitation and river discharge will help elucidate how the estuarine ecosystem may respond to climate changes. Precipitation patterns in the Altamaha River watershed were described using empirical orthogonal functions (EOFs) of the combined multidecadal time series of precipitation at 14 stations. The first EOF (67 % of the variance) was spatially uniform, the second EOF (11 %) showed a spatial gradient along the long axis of the watershed (NW–SE), and the third EOF (6 %) showed a NE–SW pattern. We compared the principal components (PCs) associated with these EOFs, monthly standardized anomalies of Altamaha River discharge at the gauge closest to the estuary, and the climate indices. Complex, seasonally alternating patterns emerged. The BHI was correlated with June–January discharge and precipitation PC 1. The SOI was correlated with January–April discharge and precipitation PC 2, and also weakly correlated with PC 1 in November–December. The AMO was correlated with river discharge and precipitation PC 3 mainly in December–February and June. The correlation patterns of precipitation PCs with PDO and PNA were similar to those with SOI, but weaker. There were no consistent relationships with two NAO indices or IEMI. Connections between climate signals and estimates of nutrient loading were consistent with the connections to discharge. The occurrence of tropical storms in the region was strongly related to the BHI but not to the other climate indices, possibly representing the influence of storm tracking more than the rate of storm formation. Comparison with the literature suggests that the patterns found may be typical of southeastern USA estuaries but are likely to be different from those outside the region. 相似文献
13.
黄河源区降水与径流过程对ENSO事件的响应特征 总被引：19，自引：10，他引：19
根据最新季分辨率ENSO指数序列所确认的近40年多来所发生的20次ENSO事件，并确定了每次ENSO事件强度及其影响年，通过对相应年份黄河源区降水与径流距平变化值的对比，分析了降水与径流过程对ENSO事件响应的统计规律；ENSO事件与黄河源区降水与径流年际波动变化有很好的相关性，这种相关性与ENSO事件的性质强弱，发生季节以及持续时间等有关。一般夏秋季暖事件无论强弱均使影响年降水减少，发生于春季的中等强度暖事件使发生年降水呈负距平，影响年降水呈增加趋势，冷事件与暖事件对降水的影响正好相反；暖事件对应年份黄河源区径流量减少，而冷事件则使其增加，随着20世纪90年代以来暖事件发生频率的增加，径流呈现持续减少。 相似文献
14.
15.
Temporal Change Characteristics of Climatic and Its Relationships with Atmospheric Circulation Patterns in Qinghai Lake Basin 总被引：1，自引：0，他引：1
Based on monthly meteorological data from 11 stations(1959-2015)in Qinghai Basin(QHB) and its surrounding area, we analyzed monthly average temperature(Tmean), average maximum(TXam), minimum temperature(TNam) and precipitation variation characteristics as well as the influence of atmospheric oscillation on these parameters using Mann-Kendall trend analysis, mutation analysis, continuous Morlet wavelet transform, Pearson correlation analysis and R/S analysis method. In addition, the future trend of climate change in the regional scale was also discussed. We found that the temperature and precipitation increment were obvious in the region, especially the Tmean in autumn, winter, TXam and TNam in summer and winter precipitation showing significant increase. Temperature and precipitation experienced abrupt changes around 1986 and 2002, respectively. The period of oscillation of each temperature indices was similar featuring 2~3 years,8~10 years short- cycle and 30~32 years middle- cycle, while that for the precipitation featured 3~4 years,6~7 years short- cycle and 30~32 years middle- cycle. The East Asian Summer Monsoon Index(EASMI) anomaly is an important factor for the anomaly of autumn temperature and summer precipitation in QHB, while the Indian Summer Monsoon Index(ISMI) mainly affects the spring temperature and precipitation in the research area. The effects of Arctic Oscillation Index (AO) were relatively strong on temperature variation, especially in autumn and winter, and AO had significant effect on the precipitation in spring, summer and winter, too. The North Atlantic Oscillation Index (NAO) and ENSO have weak influence on the study area, NAO mainly affects summer and winter precipitation, while ENSO mainly affects autumn precipitation. The Hurst index of Tmean and annual precipitation in QHB are higher than 0.5, indicating that the temperature and precipitation in the study area will continue to be the positive trend in the future period. 相似文献
16.
Regional climate change and its effects on the runoff of Manas River,Xinjiang, China 总被引：5，自引：3，他引：2
The effects of climate change on annual runoff were analyzed on the basis of hydrologic and meteorological data for the past
50 years recorded by six meteorological stations and the Kenswatt Hydrological Station in the headstream of the Manas River
watershed. The long-term trends of climate change and hydrological variations were determined in a nonparametric test, and
the periodicities were determined employing the extrapolation method of periodic variance analysis. Subsequently, a periodicity-trend
superposition model was used to predict future change. The results show that both the climate factors (temperature and precipitation)
and runoff have increased considerably and have significant relations; the relation between temperature and runoff is the
more significant. There is periodicity of 18 years in the change in annual runoff, and the primary periodicity of changes
in temperature and precipitation is, respectively, 3 and 15 years. The runoff variations are affected by climate change in
the headstream, but do not shift simultaneously with abrupt changes in temperature and precipitation in the headstream. There
is a significant positive relationship in winter between the North Atlantic Oscillation (NAO) and runoff, while there are
negative correlations annually and in summer for the runoff lagging the NAO by 1 year. The NAO has certain effects on climate
change that are mainly due to atmospheric circulation in the Manas River Basin, and thus, the NAO affects the runoff. 相似文献
17.
剖析"太阳-气候-水资源"体系作用机制对区域水资源科学管理具有重要科学意义。利用相关分析、主成分分析和小波分析方法,探究太阳黑子运动和厄尔尼诺（ENSO）对日本吉野川流域降雨、地表径流和地下水位影响。研究结果表明:太阳黑子活动和ENSO对研究区域水文过程显著影响分别发生在11 a和2~7 a周期上;太阳黑子运动能量以ENSO为"媒介"作用于流域降水和河川径流,但对地下水位波动影响不明显;太阳黑子活动在不同时频域对研究区域水文过程产生"直接"和"间接"影响,太阳黑子的"直接"影响可能通过调制ENSO外的气候模态来实现,其"间接"作用则通过"ENSO-西太平洋副高-东亚环流-水汽运动"系统作用实现。 相似文献
18.
全球变暖背景下,偶发极端冷事件产生的重大灾害损失不容忽视。探究区域极端冷事件的大尺度驱动因子的耦合影响,对预估和应对气候变化产生的极端灾害具有重要意义。本文基于新疆1961—2016年53个气象站点的逐日气温资料,通过反距离加权等方法对极端冷事件的时空演变特征进行分析;利用交叉小波变换对6个极端冷指数与大尺度驱动因子——北极涛动（AO）、北大西洋涛动（NAO）和厄尔尼诺-南方涛动（ENSO）进行多尺度分析;使用参数假设检验对大尺度驱动因子单一/耦合模态下的冷指数变化进行统计学显著性检验,随后对大尺度环流机制进行距平合成分析。结果表明：年均冷指数在时间尺度上均有显著性变化,新疆气温有明显的变暖趋势;空间尺度上冷指数在北疆、东疆和伊犁河谷地区的变化幅度远大于其他区域,存在空间差异性。AO、NAO与冷指数的相关性较强,ENSO与冷指数相关关系最弱但存在明显的时滞效应,大尺度驱动因子对极端冷指数的总体影响程度为AO>NAO>ENSO。单一模态下,极端冷事件在AO负位相、NAO负位相和La Ni?a事件期间易发生。耦合模态下,EI Ni?o-AO正位相和EI Ni?o-NAO正位相配置下冷日日数偏多;EI Ni?o-NAO负位相配置时极端低温值更小;La Ni?a-AO负位相和La Ni?a-NAO正位相时极端冷事件发生的可能性更大。EI Ni?o（La Ni?a）事件对AO（NAO）有一定的调制作用。新疆极端冷事件更易出现在La Ni?a-AO负位相、La Ni?a-NAO正位相时期,成因与亚欧大陆中高纬度位势异常导致冷空气路径偏西、乌拉尔阻塞加强与偏北气流影响新疆有关。 相似文献