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1.
Christopher S. Moses William T. Anderson Colin Saunders Fred Sklar 《Journal of Paleolimnology》2013,49(1):5-14
Precipitation and temperature in Florida responds to climate teleconnections from both the Pacific and Atlantic regions. In this region south of Lake Okeechobee, encompassing NWS Climate Divisions 5, 6, and 7, modern movement of surface waters are managed by the South Florida Water Management District and the US Army Corps of Engineers for flood control, water supply, and Everglades restoration within the constraints of the climatic variability of precipitation and evaporation. Despite relatively narrow, low-relief, but multi-purposed land separating the Atlantic Ocean from the Gulf of Mexico, South Florida has patterns of precipitation and temperature that vary substantially on spatial scales of 101–102 km. Here we explore statistically significant linkages to precipitation and temperature that vary seasonally and over small spatial scales with El Niño-Southern Oscillation (ENSO), the Atlantic Multidecadal Oscillation (AMO), and the Pacific Decadal Oscillation (PDO). Over the period from 1952 to 2005, ENSO teleconnections exhibited the strongest influence on seasonal precipitation. The Multivariate ENSO Index was positively correlated with winter (dry season) precipitation and explained up to 34 % of dry season precipitation variability along the southwest Florida coast. The AMO was the most influential of these teleconnections during the summer (wet season), with significant positive correlations to South Florida precipitation. These relationships with modern climate parameters have implications for paleoclimatological and paleoecological reconstructions, and future climate predictions from the Greater Everglades system. 相似文献
2.
《自然地理学》2013,34(1):76-96
Regions based on seasonal precipitation variability for Hawaii are determined using a principal components analysis applied to 124 stations for the period 1971-2000. Nine regions are delineated and are consistent with known precipitation patterns; leeward and windward stations are in separate regions on all islands. Within each region, the relationship between precipitation and the El Niño-Southern Oscillation (ENSO) is examined using a correlation analysis with the Southern Oscillation Index (SOI), and the Niño 3.4 and Niño 1+2 indices. Precipitation is most frequently correlated with ENSO in the different regions using SOI and Niño 3.4. Using several nonparametric statistical tests, it is determined that while average precipitation received in Hawaii during El Niño events is significantly different from average precipitation (1971-2000) and from precipitation received during La Niña events, the relationship between precipitation and individual ENSO events within regions is rarely significant. Finally, during El Niño or La Niña events, average precipitation receipt across the regions co-varies during winter and summer under concurrent conditions and a one-season lag. Synoptic patterns are examined and indicate a deviation from average conditions during ENSO events that affects subsidence and precipitation patterns. 相似文献
3.
《寒旱区科学》2019,(6)
Spatial and temporal variations in moisture conditions across monsoon Asia were investigated using 347 Monsoon Asia Drought Atlas(MADA) grid points and 100 Chinese historical documents sites during the years 1470-2000. We applied Rotated Empirical Orthogonal Function(REOF) analysis to evaluate spatial moisture variability during the past 530 years.The first 13 principal components together explained 61.35% of the total variance, with the First Principal Component(PC1) accounting for 14.1%. After varimax rotation to the first 13 EOFs, we obtained new time series and spatial patterns.These patterns divided monsoon Asia into 13 regions with coherent moisture variability. Drought events were analyzed within these 13 regions. The results indicate that there has been a prominent drying trend in eastern and central Mongolia,Southeast Asia and east China during the last 50 years. Conversely, India and the Tibetan Plateau show a significant increase in moisture around the late 20 th century. We found four drought periods, A.D. 1625-1644, A.D. 1710-1729, A.D.1920 s, and A.D. 1975-1999 occurred widely across monsoon Asia during the past 530 years. On inter-annual time scales,moisture variations in the northwest region of monsoon Asia, the Indian subcontinent and Southeast Asia are influenced by the El Ni?o-Southern Oscillation(ENSO). Thirty-year running correlation coefficient diagnostic analysis revealed that moisture variability in monsoon Asia is associated with the Pacific Decadal Oscillation(PDO). 相似文献
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5.
中国季风降水与赤道东太平洋海温的关系 总被引：3，自引：0，他引：3
本文根据近38年(1951—1988年)海平面气压场与我国160个站降水的冬夏距平值,研究了季风降水与赤道东太平洋海温(SST)变化的关系,发现两者有联系的年占一定优势。季风降水与SST的关系虽非逐年对应,但SST异常对东亚季风气压场的年际变化及我国降水变化仍是一个不可忽视的影响因素。 相似文献
6.
BY FIDEL A. ROIG DAVID BARRIOPEDRO RICARDO GARCÍA HERRERA DANIEL PATÓN DOMINGUEZ SUSANA MONGE 《Geografiska Annaler: Series A, Physical Geography》2009,91(2):141-157
Exactly dated ring-width chronologies derived from Pyrenean oak and sweet chestnut trees growing in northern Extremadura, Spain, were evaluated for their potential as proxies for regional precipitation and North Atlantic Oscillation variability. The relationships among tree-rings, instrumental climatic records, and three versions of the NAO index were computed for different time subperiods over the last century. The results indicate that tree-ring records reflect, with variable intensity, both short-term and long-term variations in climate. Multiple correlation and regression analysis revealed that summer precipitation appeared to be the major factor affecting tree growth at inter-annual timescales. Moreover, since fluctuations in accumulated variability in annual rainfall over southwest Iberia are controlled by winter precipitation, the accumulated rainfall (August of the year n -1 to July of year n ) and winter NAO indices are also strongly correlated with tree-ring records at interdecadal timescales. This relationship appears to be especially strong during the second half of the 20th century, which is consistent with an increase of the NAO signal in the annual precipitation during the later part of the century. These results indicate that tree-rings from western Iberia are potential proxies of the NAO variability, useful to be included in palaeoclimatic model studies. 相似文献
7.
中国季风降水与赤道东太平洋海温的关系* 总被引：1，自引：1，他引：0
本文根据近38年(1951—1988年)海平面气压场与我国160个站降水的冬夏距平值,研究了季风降水与赤道东太平洋海温(SST)变化的关系,发现两者有联系的年占一定优势。季风降水与SST的关系虽非逐年对应,但SST异常对东亚季风气压场的年际变化及我国降水变化仍是一个不可忽视的影响因素。 相似文献
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9.
西南地区大气降水中氢氧稳定同位素特征与水汽来源 总被引：8，自引：0，他引：8
为阐明西南地区稳定同位素与大气降水的关系,对GNIP昆明、贵阳、桂林、成都站点δD和δ18O进行分析,初步建立当地大气降水线方程,并与中国及全国降水线方程进行对比,揭示该降水线方程的特征.研究表明：大气降水稳定同位素组成受到温度、蒸发、水汽源地等多种因素的相互影响,在不同时间有很大差异.西南地区降水中的δ18O值表现出“夏高冬低”的季节特点.d值呈现出降水中过量氘水汽来源不同的特点,贵阳和桂林地区d值表现为“冬高夏低”的季节特点,而昆明和成都地区却与此相反,d值则表现为“夏高冬低”独特的季节性特征. 相似文献
10.
华北平原降水的长期趋势分析(英文) 总被引：4，自引：1，他引：3
The North China Plain (NCP) is the most important food grain producing area in China and has suffered from serious water shortages. To capture variation water availability, it is necessary to have an analysis of changing trends in precipitation. This study, based on daily precipitation data from 47 representative stations in NCP records passed the homogeneity test, analyzed the trend and amplitude of variation in monthly, seasonal and annual precipitation, annual maximum continuous no-rain days, annual rain days, rainfall intensity, and rainfall extremes from 1960 to 2007, using the MannKendall (M-K) test and Sen’s slope estimator. It was found that monthly precipitation in winter had a significant increasing trend in most parts, while monthly precipitation in July to September showed a decreasing trend in some parts of NCP. No significant changing trend was found for the annual, dry and wet season precipitation and rainfall extremes in the majority of NCP.A significant decreasing trend was detected for the maximum no-rain duration and annual rain days in the major part of NCP. It was concluded that the changing trend of precipitation in NCP had an apparent seasonal and regional pattern, i.e., precipitation showed an obvious increasing trend in winter, but a decreasing trend in the rainy season (July to September), and the changing trend was more apparent in the northern part than in the southern and middle parts. This implies that with global warming, seasonal variation of precipitation in NCP tends to decline with an increasing of precipitation in winter season, and a decreasing in rainy season, particularly in the sub-humid northern part. 相似文献
11.
The vulnerable ecosystem of the arid and semiarid region in Central Asia is sensitive to precipitation variations. Long-term changes of the seasonal precipitation can reveal the evolution rules of the precipitation climate. Therefore, in this study, the changes of the seasonal precipitation over Central Asia have been analyzed during the last century (1901–2013) based on the latest global monthly precipitation dataset Global Precipitation Climatology Centre (GPCC) Full Data Reanalysis Version 7, as well as their relations with El Niño- Southern Oscillation (ENSO). Results show that the precipitation in Central Asia is mainly concentrated in spring and summer seasons, especially in spring. For the whole study period, increasing trends were found in spring and winter, while decreasing trends were detected in summer and fall. Inter-annual signals with 3–7 years multi-periods were derived to explain the dominant components for seasonal precipitation variability. In terms of the dominant spatial pattern, Empirical orthogonal function (EOF) results show that the spatial distribution of EOF-1 mode in summer is different from those of the other seasons during 1901–2013. Moreover, significant ENSO-associated changes in precipitation are evident during the fall, winter, spring, and absent during summer. The lagged associations between ENSO and seasonal precipitation are also obtained in Central Asia. The ENSO-based composite analyses show that these water vapor fluxes of spring, fall and winter precipitation are mainly generated in Indian and North Atlantic Oceans during El Niño. The enhanced westerlies strengthen the western water vapor path for Central Asia, thereby causing a rainy winter. 相似文献
12.
夏季北极涛动与西北夏季干湿特征的年代际关系 总被引：4，自引：0，他引：4
摘要： 利用中国西北地区（新、青、甘、宁、陕及内蒙古西部地区）1960—2003年131个测站夏季降水量、小型蒸发皿蒸发量，NECP/NCAR月平均再分析资料及夏季北极涛动指数，首先通过降水量和蒸发量定义了均一化干湿指数，进而分析了夏季北极涛动同西北地区夏季干湿特征之间的关系。研究表明：夏季北极涛动与西北地区大部分地区夏季干湿特征之间存在着显著的正相关关系，特别是年代际尺度上关系尤其密切。夏季北极涛动与西北地区夏季干湿特征空间变化的南北差异密切相关，在夏季AO偏强年代，海平面气压场在东亚大陆为正距平，太平洋为负距平;700 hPa风场在贝加尔湖地区及其下方有较强的反气旋性距平环流，西北西风带区出现西风距平，季风区出现北风距平，而500 hPa高度场在中国西北地区表现为西低东高结构。这样使得东亚夏季风偏弱，西北西风带区在夏季以西风气流为主，降水偏多，气候偏湿，而季风区盛行偏北气流，降水偏少，气候偏干。反之亦然。 相似文献
13.
Hydrology of Dali Lake in central-eastern Inner Mongolia and Holocene East Asian monsoon variability 总被引：12，自引：1，他引：11
Jule Xiao Bin Si Dayou Zhai Shigeru Itoh Zaur Lomtatidze 《Journal of Paleolimnology》2008,40(1):519-528
Lacustrine records from the northern margin of the East Asian monsoon generate a conflicting picture of Holocene monsoonal precipitation change. To seek an integrated view of East Asian monsoon variability during the Holocene, an 8.5-m-long sediment core recovered in the depocenter of Dali Lake in central-eastern Inner Mongolia was analyzed at 1-cm intervals for total organic and inorganic carbon concentrations. The data indicate that Dali Lake reached its highest level during the early Holocene (11,500–7,600 cal yr BP). The middle Holocene (7,600–3,450 cal yr BP) was characterized by dramatic fluctuations in the lake level with three intervals of lower lake stands occurring 6,600–5,850, 5,100–4,850 and 4,450–3,750 cal yr BP, respectively. During the late Holocene (3,450 cal yr BP to present), the lake displayed a general shrinking trend with the lowest levels at three episodes of 3,150–2,650, 1,650–1,150 and 550–200 cal yr BP. We infer that the expansion of the lake during the early Holocene would have resulted from the input of the snow/ice melt, rather than the monsoonal precipitation, in response to the increase in summer solar radiation in the Northern Hemisphere. We also interpret the rise in the lake level since ca. 7,600 cal yr BP as closely related to increased monsoonal precipitation over the lake region resulting from increased temperature and size of the Western Pacific Warm Pool and a westward shifted and strengthened Kuroshio Current in the western Pacific. Moreover, high variability of the East Asian monsoon climate since 7,600 cal yr BP, marked by large fluctuations in the lake level, might have been directly associated with variations in the intensity and frequency of the El Niño-Southern Oscillation (ENSO) events. 相似文献
14.
This study is a broad-scale synthesis of information on climate changes in two Arctic terrestrial regions, eastern Siberia and the Alaska–Yukon area of North America. Over the past 60 years (1951–2010), the trends of temperature and precipitation in the two regions are broadly similar in their seasonality. However, atmospheric advection influences the two regions differently during winter. The differential advective effects are much weaker in the other seasons. The Pacific Decadal Oscillation is the strongest correlator with interannual variability in the two regions, followed by the Arctic Oscillation and the El Niño/Southern Oscillation.Projected changes by the late 21st Century are qualitatively similar to the changes that have been ongoing over the past 60 years, although the rate of change increases modestly under mid-range forcing scenarios (e.g., the A1B scenario). The greatest warming is projected to occur farther north over the Arctic Ocean in response to sea ice loss. Precipitation is projected to increase by all models, although increases in evapotranspiration preclude conclusions about trends toward wetter or drier land surface conditions. A notable feature of the future climate simulations is a strong maximum of pressure decreases in the Bering Sea region, implying further advective changes. 相似文献
15.
This analysis attempts to discern primary causes of interannual and interdecadal climate variations for precipitation and temperature regions of the conterminous United States. Varimax rotated principal components analysis of annual climate division data is used in the derivation of nine precipitation and five temperature regions. Each region's time series is examined for underlying linear trends, representing long-term climate change, and tests for variance changes, to determine regional climate variability shifts. The first six precipitation components, representing the entire eastern half of the country and the Northwest, displayed significant temporal increases. Of these, four displayed significant increases in interannual variability through time. For temperature, only the Southwestern region showed a significant change (increase) through time. However, significant reductions in temperature variability were confirmed for three regions. To determine the causes of the derived climate shifts, correlation analysis was performed with various atmospheric teleconnection indices. Precipitation trends are most strongly associated with variations in the Southern Oscillation Index (SOI) at the interannual time scale while interdecadal variations are associated more with variations in the Pacific/North American (PNA) teleconnection. Both interannual and interdecadal variations of regional temperature are most strongly related to the PNA, except for the Southwest, which showed a significant correlation to the SOI. This suggests that El Niño/Southern Oscillation (ENSO) events are the source for much of the precipitation change evident in the eastern and Northwestern United States and temperature change in the Southwest. [Key words: climate change, precipitation, temperature, El Niño, Southern Oscillation, United States climate.] 相似文献
16.
Studies on the impact of solar activity on climate system are very important in understanding global climate change. Previous studies in this field were mostly focus on temperature, wind and geopotential height. In this paper, interdecadal correlations of solar activity with Winter Snow Depth Index (WSDI) over the Tibetan Plateau, Arctic Oscillation Index (AOI) and the East Asian Winter Monsoon Index (EAWMI) are detected respectively by using Solar Radio Flux (SRF), Total Solar Irradiance (TSI) and Solar Sunspot Number (SSN) data and statistical methods. Arctic Oscillation and East Asian winter monsoon are typical modes of the East Asian atmospheric circulation. Research results show that on interdecadal time scale over 11-year solar cycle, the sun modulated changes of winter snow depth over the Tibetan Plateau and East Asian atmospheric circulation. At the fourth lag year, the correlation coefficient of SRF and snow depth is 0.8013 at 0.05 significance level by Monte-Carlo test method. Our study also shows that winter snow depth over the Tibetan Plateau has significant lead and lag correlations with Arctic Oscillation and the East Asian winter monsoon on long time scale. With more snow in winter, the phase of Arctic Oscillation is positive, and East Asian winter monsoon is weak, while with less snow, the parameters are reversed. An example is the winter of 2012/2013, with decreased Tibetan Plateau snow, phase of Arctic Oscillation was negative, and East Asian winter monsoon was strong. 相似文献
17.
S. Begzsuren J. E. Ellis D. S. Ojima M. B. Coughenour T. Chuluun 《Journal of Arid Environments》2004,59(4):50
We investigated how both droughts and dzuds (severe winter weather) control livestock mortality in a non-equilibrium steppe ecosystem of Mongolia, Gobi Three Beauty National Park. These steppe ecosystems have developed under high interannual variability of rainfall and nomadic grazing systems. Interannual precipitation variation was 39%, with 128 mm mean annual precipitation. The effect of climate variability and extreme events on livestock mortality is a critical aspect for the Mongolian economy. Analysis of drought and precipitation variability on livestock mortality rate was not significantly influenced by the index of mean annual precipitation and annual winter temperature. Overall, unlike hot dry regions, pastoral livestock mortality in the cold dry regions was affected more by dzuds and annual growing seasonal rain than by droughts. Dzuds can be frequent events, occurring as often as once every 2 and 3 years within a decade. The average annual livestock mortality for the combined drought and dzuds years (18%) was 4.8% greater than the years with dzuds alone, and 7% greater than in years with only drought. Thus livestock mortality appears to be more sensitive to dzuds than to droughts, and that dzuds contributes more to livestock mortality even years where combined drought and winter storms occur. 相似文献
18.
Rengui Jiang Ruijuan Cao Xi Xi Lu Jiancang Xie Yong Zhao Fawen Li 《Singapore journal of tropical geography》2020,41(3):384-412
Extreme precipitation indices (EPIs) were defined to quantify the precipitation extremes in Singapore, a typical tropical country situated near the equator. The paper investigated the spatial and temporal variability of precipitation extremes based on seventeen EPIs using non-parametric Mann-Kendall test and Sen’s slope, and further explored the linear and nonlinear relationships between precipitation extremes and four large-scale global climate oscillations using correlation and wavelet analysis, during the period of 1980–2018 in Singapore. The results indicated that the trends of precipitation extremes varied for different EPIs, regions and stations. Increasing trends dominated thirteen out of seventeen EPIs. The trends of EPIs were scattered and irregularly distributed. The cross-correlation analysis between different EPIs demonstrated that annual total precipitation on wet days (PRCPTOT) was strongly correlated with other EPIs. The result of composite analysis indicated that El Niño Southern Oscillation (ENSO) exerted stronger impacts on southwest monsoon season (SMS) precipitation than PRCPTOT and northeast monsoon season (NMS) precipitation. The SMS precipitation composite suggested that ENSO created more influence on dry spells than wet spells. The linear and nonlinear relationships revealed that all climate oscillations were negatively correlated with precipitation. The wavelet coherence and phase differences were consistent with the results of correlation analysis, indicating possible prediction of precipitation extremes using climate oscillations as potential predictors. 相似文献
19.
青藏高原降水季节分配的空间变化特征 总被引：2，自引：2，他引：0
青藏高原是全球气候变化影响的敏感区域。在全球气候变暖的背景下,其水文气候过程发生了显著的变化,直接影响到区域水资源演化。然而,目前对该区域水文气候过程的时空演变规律仍认识不足。本文以青藏高原气象站点降水观测数据为基准,结合水汽通量资料,对13种不同源降水数据集质量进行对比分析;并选用质量较好的IGSNRR数据集识别了青藏高原降水季节分配特征的空间分布格局。结果表明,青藏高原东南、西南以及西北边缘地区降水集中度和集中期较小,夏季降水占全年降水比例不足50%;随着逐渐向高原腹地推进,降水集中度和集中期逐渐增大,雨季逐渐缩短且推迟,雨季降水占全年降水比例逐渐增大。降水季节分配的空间分布格局与水汽运移方向保持一致,即主要是由西风和印度洋季风的影响所致。基于此,识别出西风的影响区域主要位于高原35°N以北,印度洋季风的影响区域主要位于高原约30°N以南,而高原中部(30°N~35°N)降水受到西风和印度洋季风的共同影响。该结果有助于进一步理解和认识青藏高原水文气候过程空间差异性。 相似文献
20.
西北干旱区极端气候水文事件特征分析 总被引：7，自引：6，他引：1
中国西北干旱区是对全球变化响应最敏感地区之一。气候变化导致气候水文系统的不稳定性加剧,极端气候水文事件的频度和强度增大、重现期缩短,灾害程度加重。借助资料分析和文献阅读,对过去50 a中国西北干旱区极端气候/水文事件的发生规律、影响机制及未来趋势进行了梳理总结,主要结论如下：（1）西北干旱区的极端气候/水文事件呈逐年增加趋势,特别是20世纪70年代以来增加显著;气温和降水极值都表现为一致的增强趋势。降水量的增多是降雨频率和强度共同增加的结果。（2）中国西北干旱区低温、降水极值在1986年左右发生了明显的突变,高温极值在1996年左右发生突变。突变后,气温和降水极值均发生了显著增强变化。（3）北半球极涡面积指数和青藏高原指数对西北干旱区气候极值变化具有重要影响,冬季极值还受冬季北极涛动和北大西洋涛动等影响。（4）新疆地区有变暖湿趋势,而河西走廊东部则为变干趋势。强大的西伯利亚高压和增强的贝加尔湖气流造成新疆地区降水增加,而河西走廊干旱增加是由东亚夏季风减弱引起的。 相似文献