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1.
利用全国175个测站1960—1999年间的日平均气温资料,分别选取1960—1989年(气候态A)、1970—1999年(气候态B)作为气候背景,采用蒙特卡洛显著性检验法检验了这两个气候态背景下我国冬夏两季季节平均气温的差异显著性。并在此基础上利用气候百分位法分别分析了在这两个气候态背景下2000—2010年间我国冬夏两季的极端气温特征。分析结果表明,相对于夏季,冬季气候态A、B背景下季节平均气温的差异更为显著。冬夏两季,我国大部分地区极端低温事件的发生频率相对较低,而极端高温事件的发生频率相对较高。由于气候态B包含了全球变暖特征最为显著的20a,故在气候态B背景下,冬夏两季极端低(高)温事件的发生频率要高(低)于气候态A,这与全球变暖的趋势相吻合。 相似文献
2.
阿勒泰地区冬季极端最低气温变化分析 总被引：1，自引：0，他引：1
李海花 《沙漠与绿洲气象(新疆气象)》2012,6(6):41-44
采用气候分析的方法,全面分析研究近49 年阿勒泰地区冬季(11～3月)极端最低气温的区域分布为东低西高,最低值出现大部在12月和1月;并且60年代的冬季在这两个月均最冷;阿勒泰地区冬季平均极端最低气温49年来呈增高趋势,H值均大于0.5,具有持续性,即过去的气温呈增高趋势在未来仍呈增高趋势。 相似文献
3.
AN ANALYSIS OF THE WINTER EXTREME PRECIPITATION EVENTS ON THE BACKGROUND OF CLIMATE WARMING IN SOUTHERN CHINA 总被引：2，自引：1，他引：1
Based on daily precipitation and monthly temperature data in southern China, the winter
extreme precipitation changes in southern China have been investigated by using the Mann-Kendall test
and the return values of Generalized Pareto Distribution. The results show that a winter climate
catastrophe in southern China occurred around 1991, and the intensity of winter extreme precipitation was
strengthened after climate warming. The anomalous circulation characteristics before and after the climate
warming was further analyzed by using the U.S. National Centers for Environmental Prediction/National
Center for Atmospheric Research reanalysis data. It is found that the tropical winter monsoon over East
Asia is negatively correlated with the precipitation in southeastern China. After climate warming the
meridionality of the circulations in middle and high latitudes increases, which is favorable for the
southward movement of the cold air from the north. In addition, the increase of the temperature over
southern China may lead to the decrease of the differential heating between the continent and the ocean.
Consequently, the tropical winter monsoon over East Asia is weakened, which is favorable for the transport
of the warm and humid air to southeastern China and the formation of the anomalous convergence of the
moisture flux, resulting in large precipitation over southeastern China. As a result, the interaction between
the anomalous circulations in the middle and high latitudes and lower latitudes after the climate warming
plays a major role in the increase of the winter precipitation intensity over southeastern China. 相似文献
4.
我国南方冬季气候变暖前后极端降水事件分析 总被引：5，自引：1，他引：5
利用我国南方逐日降水资料及逐月温度资料,采用Mann-Kendall突变检验方法,并计算极端降水的GPD(Generalized Pareto Distribution)重现值,讨论了气候变暖前后我国南方冬季极端降水事件的变化。结果表明,我国南方冬季气候变暖的突变发生在1991年前后,且气候变暖后我国南方冬季的极端降水强度普遍有所增加。利用NCEP/NCAR再分析资料进一步分析气候变暖前后的环流场特征,发现东亚热带冬季风异常与我国华南、江南地区降水异常有显著的相关关系。东亚热带冬季风偏强(弱),华南、江南地区降水偏少(多)。气候变暖后中高纬度环流经向度加大,有利于北方的冷空气向南输送。此外,气候变暖后我国南方地面气温升高,海陆热力差异减小,东亚热带冬季风减弱,有利于西太平洋的暖湿气流向我国大陆东南部输送,并在东南部形成异常的水汽通量辐合,有利于形成强降水。气候变暖后,中高纬度与中低纬度异常环流系统的相互作用是我国东南部降水强度增加的主要原因。 相似文献
5.
Vincent Kint Wim Aertsen Matteo Campioli Dries Vansteenkiste Andy Delcloo Bart Muys 《Climatic change》2012,115(2):343-363
Both increasing and decreasing 20th century growth trends have been reported in forests throughout Europe, but only for few species and areas suitable modelling techniques have been used to distinguish individual tree growth (operating on a local scale) from growth change due to exogenous factors (operating on a broad geographical scale). This study relates for the first time observed growth changes, in terms of basal area increment (BAI) of dominant trees of pedunculate oak, common beech and Scots pine, in north-west European temperate lowland forests (Flanders) to climate, atmospheric CO2 and tropospheric O3 concentrations, N deposition, site quality and forest structure for more than a century (the period 1901?C2008), applying mixed models. Growth change during the 20th century is observed for oak (increasing growth) and beech (increasing growth until the 1960s, growth decline afterwards), but not for pine. It was possible to relate growth change of oak and beech to climate time series and N deposition trends. Adding time series for CO2 and O3 concentration did not significantly improve model results. For oak and beech a switch from positive to negative growth response with increasing nitrogen deposition throughout time is observed. Growth increase for oak is mainly determined by the interaction between growing season temperature and soil water recharge. It is reasonable to assume that the observed growth trend for oak will continue for as long as early season water availability is not compromised. The decreasing trend in summer relative air humidity observed since the 1960s in the study area can be a main cause of recent beech BAI decrease. A further growth decline of beech can be expected, independent of site quality. 相似文献
6.
中国夏季和冬季极端干旱年代际变化及成因分析 总被引：4，自引：0，他引：4
依据1961～2009年中国区域540个气象站的夏、冬季气温和降水数据,首先采用气候变化趋势转折判别模型（简称PLFIM）分析了中国区域8个分区夏、冬季气温和降水的年代际变化,而后利用PDSI干旱指数研究了夏、冬季极端干旱在年代际尺度上的时空变化特征及其成因。结果表明:1961～2009年中国夏季极端干旱发生率北方大于南方,冬季则为在东部多而在西部少。夏季和冬季极端干旱发生概率在最后一次年代际转折后都呈增加趋势。在区域尺度上,夏季东北、华北和西北地区增加明显,冬季东北、华北、华南、西南地区增加显著。其中,降水在20世纪90年代以前的极端干旱变化中起主导作用,而后由于气候变暖所引起的极端干旱增加趋势逐渐增大,与降水变化的作用相互叠加。 相似文献
7.
A variable-grid atmospheric general circulation model, LMDZ, with a local zoom over southeast China is used to investigate regional climate changes in terms of both means and extremes. Two time slices of 30?years are chosen to represent, respectively, the end of the 20th century and the middle of the 21st century. The lower-boundary conditions (sea-surface temperature and sea-ice extension) are taken from the outputs of three global coupled climate models: Institut Pierre-Simon Laplace (IPSL), Centre National de Recherches Météorologiques (CNRM) and Geophysical Fluid Dynamics Laboratory (GFDL). Results from a two-way nesting system between LMDZ-global and LMDZ-regional are also presented. The evaluation of simulated temperature and precipitation for the current climate shows that LMDZ reproduces generally well the spatial distribution of mean climate and extreme climate events in southeast China, but the model has systematic cold biases in temperature and tends to overestimate the extreme precipitation. The two-way nesting model can reduce the ??cold bias?? to some extent compared to the one-way nesting model. Results with greenhouse gas forcing from the SRES-A2 emission scenario show that there is a significant increase for mean, daily-maximum and minimum temperature in the entire region, associated with a decrease in the number of frost days and an increase in the heat wave duration. The annual frost days are projected to significantly decrease by 12?C19?days while the heat wave duration to increase by about 7?days. A warming environment gives rise to changes in extreme precipitation events. Except two simulations (LMDZ/GFDL and LMDZ/IPSL2) that project a decrease in maximum 5-day precipitation (R5d) for winter, other precipitation extremes are projected to increase over most of southeast China in all seasons, and among the three global scenarios. The domain-averaged values for annual simple daily intensity index (SDII), R5d and fraction of total rainfall from extreme events (R95t) are projected to increase by 6?C7, 10?C13 and 11?C14%, respectively, relative to their present-day values. However, it is clear that more research will be needed to assess the uncertainties on the projection in future of climate extremes at local scale. 相似文献
8.
In this study we examine the performance of eight of the IPCC AR4 global coupled climate models used in the WCRP CMIP3 Multimodel Dataset, as well as their ensemble mean, in simulating annual indices of extreme temperature and precipitation climate events in South America. In this first part we focus on comparing observed and modeled mean values and interannual variability. Two extreme temperature indices based on minimum temperature (warm nights and frost days) and three indices of extreme precipitation (R95t, R10 and consecutive dry days), obtained both from meteorological stations during 1961–2000 and model outputs, were compared. The number of warm nights are better represented by models than the FD. The interannual variability pattern is also in good agreement with the observed values. For precipitation, the index that is best represented by the models is the R95t, which relates the extreme precipitation to local climate. The maximum of dryness observed over the central Argentinian Andes or the extensive dry season of the Amazon region could not be represented by any model. 相似文献
9.
利用1961—2022年江西74个气象站平均气温、最高气温、最低气温、降水量、相对湿度、平均风速和日照时数资料,对比分析了1991—2020年和1981—2010年新、旧气候态下气象要素差异,探讨气候平均值改变对气候影响评价和预测业务的影响。结果表明：新气候态下,江西省三类气温的年和季节平均值均上升,年降水量总体增加将弱化气温偏高、降水偏多的变化特征。年和季节平均风速距平山区减小而平原地区增大;年日照时数距平总体增加。极端高温年份减少,极端低温年份增多,其中平均气温和最低气温的极端高（低）温年发生概率的降幅（增幅）比最高气温更大。极端强降水年发生概率在赣西北、赣中大部、赣南西北部等地区夏季减少,赣南中南部地区冬季增大。全省历年极端日高温、低温和强降水事件发生站次总体减少。新、旧气候态的更替会对气候业务产生影响,如冬季气温偏冷的年份增加,偏暖的年份减少,需对冷、暖冬事件进行重新评估,夏季降水增多的变化特征减弱,将导致夏季降水预测量级和趋势发生改变。 相似文献
10.
Evaluation of climate change over the continental United States using a moisture index 总被引：2，自引：0，他引：2
Andrew Grundstein 《Climatic change》2009,93(1-2):103-115
This paper uses a modified form of Thornthwaite’s moisture index to better quantify climate variability by integrating the effects of temperature and precipitation. Using the moisture index, trends were evaluated over the last 112 years (1895–2006), when unique changes in temperature and precipitation have been documented to have occurred. In addition, data on potential evapotranspiration and the moisture index were used to investigate changing climate and vegetation regions. The results show that the eastern half of the country has been getting wetter, even as temperatures have continued to increase in many areas. In particular, conditions have become wetter in the South, Northeast, and East North Central regions. The changing climate is illustrated by computing climate and vegetation regions for three 30-year periods (1910–1939, 1940–1969, and 1970–1999). Climate regions based on the moisture index show an expansion of the Humid region (where precipitation vastly exceeds climatic demands for water) across the East as well as a westward shift in the zero moisture index line. In terms of vegetation zones, the most dramatic change occurs across the Midwestern prairie peninsula where the wetter conditions lead to a westward expansion of conditions favorable for oak–hickory–pine vegetation. 相似文献
11.
Dieter Wagner 《Climatic change》1996,33(3):385-407
Based on the principles of the probability theory a statistical model has been developed assessing the likelihood of occurrence of extreme temperature events from the knowledge of the statistical characteristics of the daily temperature extremes. It is demonstrated that the probability of such events is more sensitive to changes in the variability of climate than to changes in its average. Further, this sensitivity increases at a nonlinear rate the more extreme the event. The applicability of the model has been verified by comparing the simulated frequencies of a large spectrum of temperature events with the observed numbers derived from a long time series of daily temperature extremes at Potsdam. Accordingly, the relative simulation errors increase significantly as the events become more extreme. A correction is possible, because most of these errors are systematic rather than random. Moreover, in accordance with the climate observations the simulations reveal statistically significant linear trends in the number of extreme events since the end of the last century. Local scenarios of extreme temperature events have been derived for the city of Berlin by considering both hypothetical new climate states and climate changes simulated by a General Circulation Model (GCM). As a consequence of an increase in the atmospheric concentration of greenhouse gases up to the end of the next century according to the IPCC Scenario A the repetition rate of extreme events in summer (e.g., hot days) is expected to rise considerably relative to the current climate. Moreover, in the winter season cold days will become extremely rare. 相似文献
12.
North-Atlantic SST amplified recent wintertime European land temperature extremes and trends 总被引：2，自引：2，他引：0
Europe has been warming over the past 30?years. In particular all seasonal temperature records have been broken since 2003, which altered socio-economic and environmental systems. Since we expect this trend in both mean and extreme temperatures to continue along the twenty first century under enhanced radiative forcing, it is crucial to understand the underlying mechanisms of such climate variations to help in considering adaptation or mitigation strategies to reduce the impacts of a warmer climate. From a statistical analysis we show that the inter-annual variability of European seasonal temperatures can be reconstructed from North-Atlantic atmospheric circulation only, but not their recent trends and extreme seasons. Adding North-Atlantic sea-surface temperature (SST) as a predictor helps improving the reconstruction, especially in autumn and winter. Sensitivity experiments with the MM5 regional model over 2003?C2007 suggest that the anomalous SST enhance European land temperatures through the upper-air advection of heat and water vapor, interacting with radiative fluxes over the continent. This mechanism is pronounced in autumn and winter, where estimates of SST influence as obtained from MM5 are in agreement with those obtained from statistical regressions. We find a lesser SST influence in spring and summer, where local surface and radiative feedbacks are the main amplifiers of recent extremes. 相似文献
13.
秋季北极海冰对中国冬季气温的影响 总被引：7，自引：0，他引：7
利用海冰资料、中国地面气候资料、环流特征量资料及NCEP/NCAR再分析资料,研究了秋季北极海冰变化对中国冬季平均气温、日气温变率以及异常低温天气的影响。分析结果表明,秋季北极海冰异常偏多年中国冬季常为暖冬;异常偏少年中国冬季常为冷冬,且异常低温天气出现频率更高,常发生低温灾害事件。秋季北极海冰通过影响后期的北半球极涡、东亚冬季风和西伯利亚高压进而影响中国冬季的平均气温,且通过影响冬季异常强西伯利亚高压的出现频次,影响中国冬季异常低温天气的发生频次。合成分析结果表明,秋季北极海冰异常偏少年的冬季,中国以北亚欧大陆高纬度的偏北风较强,且中国及其以北的中高纬度地区空气异常偏冷,导致极地和高纬度的冷空气易向南爆发,造成中国冬季气温偏低,异常低温天气频发。 相似文献
14.
An iterative chi-square method is applied to determine recent climate change of extremes of daily minimum temperature at two locations between an 18-year recent period and a 36-year prior period. The method determines for each of two locations in northwestern North America, Bozeman, Montana, USA and Coldstream, British Columbia, Canada, which values of the extreme daily weather elements are most significantly different between the prior years and the recent years and gives a measure of the weekly significance of that difference. Determination was made of the average percent of each recent year date (plotted weekly) that was impacted by extreme weather due to climate change as well as the percentage change in the frequency of the number of extreme days for each period of contiguous significant weeks. During the recent period at both locations, most weeks experienced a greater number of days of extreme high minimum temperature and a fewer number of days of extreme low minimum temperature. The weekly percentage changes indicate that extreme high minimum temperatures at both Bozeman and Coldstream are increasing at the rate of about 10% per decade, with a close corresponding decrease of extreme low minimum temperatures. The major changes in climate were very similar at both locations, with greatest warming occurring during the late winter and early spring and during the late July to August period. 相似文献
15.
以1960年以来西藏境内已有记载的27次冰湖溃决灾害事件作为研究对象,基于西藏国家气象站点长时间序列（有效记录至今）日气温和日降雨数据,计算得到16个极端气温指数和6个极端降雨指数。通过主成分变换,提取综合极端气温指数和综合极端降雨指数,并进行历史（10年内对比）极端气候特征对比,获得冰湖溃决灾害发生当年及当月极端气候状态,结果表明西藏冰湖溃决灾害发生期（当年及当月）极端气候特征显著,反映极端气候状态对于激发西藏冰湖溃决灾害发生的重要贡献,具体表现为：(1) 67%（18次）的冰湖溃决事件发生当年综合极端气温指数和综合极端降雨指数均大于前期50%年份的综合极端气候指数,其中,13次灾害发生当年极端气候异常水平超过前期70%年份;(2)已有灾害暴发月份记载的25次冰湖溃决事件中,19次冰湖溃决事件发生当月极端气候指数异常偏高,11次冰湖溃决事件发生当月极端气温和极端降水均大于75%往年同期综合极端气候指数;(3)部分灾害事件如扎日错（1981年6月)、龙纠错溃决（2000年8月）等,灾害发生当年极端气温状态低于往年,而暴发当月综合极端气温指数和综合极端降雨指数均大于历史同期水平,表现为加剧状态;(4)所有冰湖溃决灾害发生当月的综合极端气温指数均高于往年同期指数,表明短历时极端气温事件对高原冰湖溃决灾害形成具有重要影响。 相似文献
16.
A multi-proxy reconstruction of spatial and temporal variations in Asian summer temperatures over the last millennium 总被引：1，自引：0，他引：1
To investigate climate variability in Asia during the last millennium, the spatial and temporal evolution of summer (June–July–August; JJA) temperature in eastern and south-central Asia is reconstructed using multi-proxy records and the regularized expectation maximization (RegEM) algorithm with truncated total least squares (TTLS), under a point-by-point regression (PPR) framework. The temperature index reconstructions show that the late 20th century was the warmest period in Asia over the past millennium. The temperature field reconstructions illustrate that temperatures in central, eastern, and southern China during the 11th and 13th centuries, and in western Asia during the 12th century, were significantly higher than those in other regions, and comparable to levels in the 20th century. Except for the most recent warming, all identified warm events showed distinct regional expressions and none were uniform over the entire reconstruction area. The main finding of the study is that spatial temperature patterns have, on centennial time-scales, varied greatly over the last millennium. Moreover, seven climate model simulations, from the Coupled Model Intercomparison Project Phase 5 (CMIP5), over the same region of Asia, are all consistent with the temperature index reconstruction at the 99 % confidence level. Only spatial temperature patterns extracted as the first empirical orthogonal function (EOF) from the GISS-E2-R and MPI-ESM-P model simulations are significant and consistent with the temperature field reconstruction over the past millennium in Asia at the 90 % confidence level. This indicates that both the reconstruction and the simulations depict the temporal climate variability well over the past millennium. However, the spatial simulation or reconstruction capability of climate variability over the past millennium could be still limited. For reconstruction, some grid points do not pass validation tests and reveal the need for more proxies with high temporal resolution, accurate dating, and sensitive temperature signals, especially in central Asia and before AD 1400. 相似文献
17.
本文对2000年以来京津冀城市群气候变化及影响适应的研究成果进行了综述。研究表明：20世纪60年代以来,京津冀城市群年平均气温和极端高温指数显著升高,年降水量波动减少,到21世纪10年代,极端强降水指数降低。京津冀气候变化是全球变暖和城市化共同作用的结果,城市化加速了京津冀变暖趋势,增加了极端高温和极端强降水的频率和强度,气候风险高。未来京津冀城市群协同发展,面临高温热浪、强降水、水资源短缺和海平面上升等风险将更严峻,气候变化适应是京津冀城市群可持续发展面临的紧迫问题,适应策略等方面研究已取得了明显进展,但适用性和针对性还存在不足。本文提出了未来研究展望：深入研究城市化对气候变化的反馈,发展全球气候变化和城市化共同作用下的气候风险精细化预估技术,系统研究气候变化对城市的影响和不同行业的脆弱性,加强温室气体监测评估技术研究,加强适应气候变化的策略、路径和技术研究。 相似文献
18.
The high sensitivity of the Arctic implies that impact of climate change and related environmental changes on river discharge can be considerable. Sensitivity of discharge to changes in precipitation, temperature, permafrost and vegetation, was studied in the Usa basin, Northeast-European Russia. For this purpose, a distributed hydrological model (RHINEFLOW) was adapted. Furthermore, the effect of climate change simulated by a GCM (HADCM2S750 integration) on runoff was assessed, including indirect effects of permafrost thawing and changes in vegetation distribution. The study shows that discharge in the Usa basin is highly sensitive to changes in precipitation and temperature. The effect of precipitation change is present throughout the year, while temperature changes affect discharge only in seasons when temperature fluctuates around the freezing point (April and October). Discharge is rather sensitive to changes in vegetation. Sensitivity to permafrost occurrence is high in winter, because infiltration and consequently base flow increases if permafrost melts. The effect of climate change simulated by the scenario on discharge was significant. Peak flow can both decrease (by 22%) and increase (by 19%) comparedwith present-day, depending on the amount of winter precipitation. Also, runoff peaks earlier in the season. These results can have implications for the magnitude and timing of the runoff peak, break-up and water-levels. 相似文献
19.
应用均一化逐日气象观测资料,分析了北京地区1960—2008年气候变暖及主要极端气温指数的统计特征。结果表明：近49年来北京年平均气温增温速率约为0.39℃/10a,最高、最低气温变化具有明显的非对称性。霜冻日数和气温年较差呈现下降趋势,暖夜指数及热浪指数呈现上升趋势,除气温年较差外,其他极端气温指数的气候变率均在加大。北京年平均气温及极端气温指数主要存在21年、15～17年及准10年周期特征。年平均气温与极端气温指数之间存在较强相关性,气候变暖突变发生前后某些极端气温指数发生频率表现出明显差异。自1980年起,北京市区极端最高气温及其增温率明显高于近郊和远郊,高温日数市区多于近郊,近郊多于远郊;近、远郊极端最低气温温差高于城、近郊温差。 相似文献
20.
利用1961年以来宁夏冬季逐日气温资料及NCEP再分析资料和环流特征量资料,重点分析了21世纪以来宁夏冬季气温异常特征及同期500 hPa环流变化特征。结果表明:冬季平均气温和最低气温极小值明显上升,夜间气温异常偏低日数显著减少,白天气温异常偏高日数显著增加,大部分地区夜间气温异常偏低日数减少趋势大于白天气温异常偏高日数的增加趋势。21世纪以来,易发生极端冷暖事件,异常偏高年份多于异常偏低年份。2007/2008冬季以后为1997年以来冬季平均气温偏低频率最高时段;冬季阶段性平均气温异常有4个特征:(1)气温异常主要出现在1月和2月;(2)异常偏低的幅度明显大于异常偏高的幅度;(3)相邻2旬间气温变化幅度增大;(4)最冷时段发生变化。从年代际变化看,冬季平均气温、最低气温极小值、白天气温异常偏高日数为最高或次高值,夜间异常偏低日数多为最低或次低值。500 hPa高度上宁夏上空是影响冬季气温异常的关键区,其年代际及冷暖年强度变化是造成气温异常的最直接原因。宁夏冬季气温对亚洲西风环流指数和西太平洋副热带高压强度指数的响应更加敏感。 相似文献