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1.
应用等效纬度-海拔模型进行地温及多年冻土制图   总被引:2,自引:2,他引:2  
This research presents a method for permafrost mapping in discontinuous permafrost regions based on equivalent latitude/elevation concept in interior Alaska. In winter months, study site has a strong temperature inversion in air up to 700 m elevation. Air temperature data and the effects of slope, aspect and elevation were used to create an equivalent latitude/elevation model. This model was well correlated with mean annual surface temperature (0.79). In this watershed, the thawing index (It≈1 400 ℃*days) at the ground surface and snow depth do not vary greatly from south facing to north facing slopes. The primary controlled factor that determines the mean annual surface temperature was the winter surface temperature. The permafrost stability is effectively controlled by the freezing index. We determined 37.5% of Caribou-Poker Creeks Research Watershed has unstable or thawing permafrost. At least 2.1% of the permafrost in this watershed may have disappeared in the last 90 years due to climate warming. This method makes it possible to evaluate the permafrost stability in the present, past and future.  相似文献   

2.
1958-2008年山西气温变化的特征及趋势研究   总被引:8,自引:0,他引:8  
With the original meteorological record, monthly report and informationized manufacture data of 109 stations during 1958-2008 archived by Shanxi Meteorological Information Center, the authors studied the variation trend and characteristics of average air temperature, average maximum and minimum air temperature, and average daily range of air temperature in Shanxi, the results show that: during the resent 51a, the warming trend of average air temperature, average maximum and minimum air temperature separately was 0.306℃/10a,0.337℃/10a and 0.363℃/10a in Shanxi, which was much higher than that of the corresponding period of the whole nation; the warming trend in winter, spring and autumn separately was 0.46℃/10a、0.35℃/10a和0.26 ℃/10a, the warming range was obviously higher than that of the whole nation, though, the warming range in summer was lower than that of the whole nation; the average daily range: was on descending trend in winter, summer and the whole year without exception, while in spring and autumn it was on weak upward trend. North Shanxi is not only the area where the seasonal and annual warming is the most obvious, but also is the area where the decreasing scope and extent of average daily range are maximum, Southwest Shanxi is the area where the increasing scope and extent of average daily range are maximum all the year round, in summer the air temperature appeared obvious dropping trend in the southeast of Shanxi; The contribution that the enhancing factor of urban heat island effect made to the seasonal average air temperature rising of moderate cities and above, is the highest in summer, and the lowest in winter.  相似文献   

3.
Based on the meteorological and hydrologic data in the Lijang(丽江) basin from 1979 to 2006,variational trend and characteristics of climate change and its effect on runoff in Yanggong(漾弓) River were examined in the study.The results show that the temperature have significantly increased in the drainage basin during the past 28 years.The average temperature increased markedly from 1979 to 2006,and the increase of temperature in winter was higher than those in other seasons.The annual precipitation varied with...  相似文献   

4.
河西内陆河流域水资源及其动态变化   总被引:1,自引:0,他引:1  
The Qilian Mountains is the cradle of all inland rivers in the Hexi arid region. The mountain glaciers are an important water resources for this region. Changes of the mountain runoffs resulted from global climate warming will have important impacts on the development of human society and economy in the region. In this paper, the river runoffs from the Qilian Mountains and their dynamic changes are analyzed on the basis of the instrumental data of precipitation, air temperature, and discharge from the weather and hydrological stations in the study area. The results show that the annual change in the mountain runoffs is affected mainly by precipitation in the east of the region, but also by temeprature in the west of the region. There are some obvious regional differences in the influence of climatic change on surface runoffs in the Hexi region. River runoffs in the western part of the Hexi region have been increasing, whereas those in the eastern part have been decreasing. River runoffs in the central part such as the Heihe River, present a slow increasing trend, although it is not quite visible  相似文献   

5.
The Lambert Glacier basin is one of particular regions in East Antarctica, because of its distinctive topography. During the repeat inland traverses carried out in recent several years, surface 2 m snow samples and shallow (10~27 m deep) cores were collected at several ten stations and at near ten stations, respectively. The stable isotopic ratios of these samples and cores were measured in order to investigate the relation of isotopes with temperature and to study the climatic change in recent decades over this area. The correlation between isotopic ratios and mean annual temperature gives that δ-temperature gradient is relatively close to that along a traverse route between Vostok and Mirnyy stations. The inconsistency of δ18O profiles of these cores makes it difficult to distinguish an overall trend of climatic change in past decades. After incorporating the result of snow accumulation variability and temperature record over 30 years at the coast station, it is believed that climate was in a little cooling and drying from 1950s to 1980s and has been in a warming period since then.  相似文献   

6.
马力  韦志刚  李娴茹  王欢  郭仕侗 《冰川冻土》2022,44(6):1757-1772
Based on the daily minimum temperature data in China from 1961 to 2018, using n-order polynomial fitting, sliding t-test, empirical Orthogonal Function analysis, Morlet wavelet transform and other methods, this paper reveals the temporal and spatial distribution characteristics of the number of cold surge (CS) day, CS frequency and CS intensity by time and region. The results are as follows. On a national level, the number of CS day, CS frequency, and CS intensity decreased from 1962 to 2000. Specifically, the trend of every element of CS has changed from a previous decrease trend to an increase trend, and the inflection point was around 2000. The CS activity occurred more frequently, became more strengthen, and last for longer time after 2000. There are obvious spatial differences in the number of CS days, CS frequency, CS intensity and their changing trends in China. The number of CS days and CS frequency reach the maximum value in northeast China and northern Inner Mongolia. Meanwhile, the CS intensity value is low in the southeast China and high in the northwest China, with the exception of southern Xinjiang. The changes in the number of CS day and the CS frequency are mainly manifested as the “Northeast, Southwest Reverse Pattern”, the CS intensity is mainly manifested as the “Uniform Change Pattern”. The number of CS day, CS frequency, and CS intensity did not change significantly after, but a significant transition point was detected in 1980. On a regional scale, from 1962 to 2018, the number of CS day, frequency and intensity of cold surge in all regions showed a decreasing trend, while they increased after 2000. In the northern and northeastern of China, mean of three elements of cold surge increased after 2000. The transition year was different in different regions. The transition year of three elements of cold surge in Northeast China were the earliest. Mean value of the number of CS day, CS frequency, and CS intensity have an oscillation period of 3~5 years in total China and all regions. In addition, the periodic oscillations of the number of CS day and CS frequency in all regions are basically the consistent. © 2022 Science Press (China).  相似文献   

7.
In permafrost regions of Qinghai-Tibetan Plateau, the critical embankment height must be considered in the process of the construction of highway, especially for the global climatic warming. In this paper, the two-dimensional numerical analysis for the critical embankment height (for gravel road surface and coarse-grained soil) has been performed by using thefinite element method. In the calculation, we think that the service life of the construction is at least 50 years. The mean annual air temperatures applied to the calculation model are -6.5 ℃, -6.0 ℃, -5.5 ℃, -5.0 ℃, -4.5 ℃ and -4.0 ℃, respectively, and the value of temperature rise are taken as 1.10℃ in the coming 50 years. The minimum embankment heights derived from the analysis are 0.85 m, 0.92 m, 1.01 m, 1.18 m, 1.60 m and 2.66 m for the different mean annual air temperatures and the maximum embankment heights are 7.68 m,7.55 m, 7.34 m, 7.00 m, 6.45 m and 5.85m, accordingly. On condition that the service life of embankment is 50 years, the critical value of the mean annual air temperature is -3.5 ℃. Namely, in the areas where the mean annual air temperature is higher than -3.5 ℃, the critical embankment height does not exist.  相似文献   

8.
The relationship between δ18O in precipitation and climatic factors is analyzed based on the observation of δ18O in precipitation and meteorological data in the four years from 1992 to 1995 at Tuotuohe Meteorological Station, Tibetan Plateau. Almost all the precipitation on the Tibetan Plateau is concentrated on the warm period of the year, while in the dry cold period, there is only a few precipitation events. Because the factors affecting δ18O in precipitation is rather complicated and the air temperature does not change too much in the precipitation season, the distribution of δ18O in precipitation with air temperature is therefore scattered. In this paper, the relationship between the averages of each meteorological factor and the corresponding δ18O in precipitation is analyzed. The analysis results indicate that there is an obvious positive correlation between the monthly δ18O and temperature in the 4 years: whenever the air temperature increases 1℃, δ18O in precipitation will increase 0. 5‰. No correlation can be observed between relative humidity and B18O in precipitation. There still can not find any correlation between the annual air temperature and annual δ18O in precipitation in the 4 years probably due to the very short time series of the observation and the little annual air temperature variations.  相似文献   

9.
Based on the study of folds and related conjugate shear joints, the tectonic stress fields of the Urumqi-Usu region to the north of the North Tianshan Mountains have been reconstructed. Furthermore the author discussed the tectonic movements and their dynamic features. The early tectonic movement in the investigated region occurred from the end of the Late Jurassic to the initial stage of the Early Cretaceous, with the maximum (tensile) and minimum (compressional) principal stress trajectories in the tectonic stress field being in E-W and S-N directions respectively; the late tectogenesis took place from the end of the Early Pleistocene to the initial Middle Pleistocene, with the maximum and minimum principal stress trajectories in the late stress field striking in WNW and NE-NNE directions respectively. Through computer-aided simulated calculation by the finite element method and analysis of geological structure, it has been ascertained that the early tectogenesis is a nearly N-S compressive movement and the late one a NE to nearly N-S compressive movement with reverse shear. The dynamic force which caused the tectogeneses came from the movement of the southern major fault, i.e. the North Tianshan Mountains.  相似文献   

10.
A massive earthquake measuring 9.0 on the Richter scale that occurred on March 11, 2011, on Honshu Island, Japan, caused radioactivity leakage from the Fukushima Nuclear Power Plant, which led to the leakage of artificial nuclides (131I, 137Cs, and 134Cs) and their global transportation by atmospheric circulation. This paper re- ports a systematic comparative observation on radioactive concentrations of natural nuclides (7Be and 210Pb) and artificial nuclides (131I, 137Cs, and 134Cs) at the surface level, measured in weekly continuous aerosol sampling at Mount Guanfeng, Guiyang, China, from March 17, 2011 to April 28, 2011. During this period, the variations in the nuclide concentrations associated with their transport paths were analyzed with 315 hour back-trajectories of air mass initialized 500 m above the surface level at Guiyang. The results show that the pollutants of nuclear leakage from the Fukushima accident were transported to the Guiyang region of China via two significant pathways. In the first pathway the first wave of nuclear pollutants were transported from west to east in air masses at higher altitudes via global atmospheric circulation. The nuclear pollutants encircled the Earth almost once and after about 10 days to two weeks, between March 24 and March 31,2011, intruded Guiyang from the northwestern region of China. In the second pathway, the nuclear pollutants from the Fukushima region arrived at Guiyang between April 7 and April 14, 201 l, via air masses at lower altitudes that moved southwards because of the squeezing of the northeast Asian weather system and then by the influence, in succession, of the northeastern and southeastern air currents in the low-latitude region. The first transport pathway for atmospheric pollutants is on a global scale and based on air masses at higher altitudes, and the second transport pathway is on an eastern Asia regional scale and based on the air masses at lower altitude.  相似文献   

11.
利用东北地区1961—2016年164个气象台站逐日平均气温和最低气温数据,根据国家标准《寒潮等级》(GB/T 21987—2017)的单站冷空气等级,计算近56年来各单站不同等级冷空气过程的频次、强度、持续日数,应用趋势系数、Mann-Kendall检验、小波分析、相似系数等统计方法,研究了东北地区三种类型寒潮(超强寒潮、强寒潮、寒潮)的气候变化特征。结果表明:三种类型寒潮日数空间分布存在明显的地区差异,高海拔地区相对偏多,低海拔和平原地区相对偏少。年尺度上,1961—2016年三种类型寒潮日数和站次呈减少趋势,减少速率呈现为超强寒潮>强寒潮>寒潮;年代尺度上,三者均在20世纪60年代到70年代末期相对偏多,1980年开始进入一个相对偏少的时段,21世纪00年代中期以后有小幅度增加;寒潮日数和站次均存在明显的3~5 a短周期性变化。1961—2016年东北地区冬季气温在空间变化上全区呈一致的增加趋势,66%的站点增温显著,检测到冬季气温的突变点为1981年。东北地区气候变暖后,三种类型寒潮日数和站次均有明显的减少。  相似文献   

12.
植被与多年冻土共同维系着大兴安岭地区的冷湿环境。随着全球气候变暖,大兴安岭多年冻土已发生严重退化,植被的生长也受到影响。在大兴安岭北部多年冻土区设置55个采样点,每个采样点采集多年冻土活动层厚度、林下灌木生物量和落叶松胸径树龄等指标,同时借助增强型植被指数(EVI)在区域尺度比较大片多年冻土区和岛状融区多年冻土区的植被生长状况。结果表明:黑龙江呼中国家级自然保护区(简称呼中保护区)活动层厚度的平均值为(0.47±0.14) m,保护区周边为(0.83±0.38) m,呼中保护区周边的活动层厚度大于保护区内。大片多年冻土区的活动层厚度平均值为(1.04±0.47) m,小于岛状融区多年冻土区的(1.40±0.41) m。呼中保护区和周边灌木生物量的平均值分别为(201.75±71.70) g·m-2和(259.10±111.14) g·m-2,胸径与树龄比值的平均值分别为(0.20±0.08)和(0.26±0.14)。大片多年冻土区和岛状融区多年冻土区林下灌木生物量的平均值分别为(128.31±63.33) g·m-2和(199.04±66.13) g·m-2,胸径树龄比的平均值分别为(0.30±0.13)和(0.59±0.21)。活动层厚度大的区域,灌木的生物量以及落叶松胸径树龄比都大于活动层厚度小的区域,表明活动层厚度增加对灌木和乔木的生长有一定的促进作用。EVI的结果显示岛状融区多年冻土区植被的生长状况以及植被覆盖情况好于大片多年冻土区,从区域尺度证明了多年冻土对植被生长存在限制作用。研究结果对于深入理解多年冻土变化及其环境效应具有重要意义。  相似文献   

13.
气候变暖背景下,极端寒冷事件仍有发生且常伴随严重的经济、社会影响,需要更为深入的研究。1929—1930年极端冷冬事件作为增暖背景下的极端冷事件,对其研究相对缺乏。通过收集并分析民国时期的气象器测资料和报刊资料,对1929—1930年中国极端冷冬事件进行探讨。结果表明: (1)本次冷冬的空间范围包括华北地区、长江流域(重庆至入海口段)和北疆地区,西北地区可能存在冷冬;寒冷的核心时段为1929年12月到次年1月。(2)本次冷冬时空范围内的地区月平均气温极端性强,华北、长江流域的12月份均温都超过十年一遇的冷事件水平,长江流域、北疆地区的1月份均温均超过五十年一遇水平;但月最低气温的极端性较弱,大部分站点月的最低温达到五年一遇水平,部分站点月超过十年一遇水平。(3)本次冷冬至少经历了7次区域性或全国性的降温事件,其中有3次降温事件达到全国性寒潮事件标准,时段分别为12月1—5日、12月16—20日和1月1—5日;其中第1次和第3次是影响中国的典型中路寒潮路径,第2次降温过程的时空特征不显著。(4)综合本次冷冬前旱后涝气候特点、该时段内ENSO(厄尔尼诺-南方涛动)指数的变化以及前人对ENSO和中国气候变异的关系研究,推测1920s末到1930s初期的气象灾害很大程度受影响于ENSO事件。  相似文献   

14.
1961-2015年内蒙古大兴安岭生态功能区气候变暖趋势明显,其气温突变年份为1987年。在气候变暖的背景下,生态功能区的严寒和寒冷日数在突变前呈减少趋势、在突变后呈增加趋势,表明突变后冬季冷天日数并没有明显减少趋势;炎热和温暖日数在突变后呈极显著增加趋势,而暖天日数突变前后变化较为平缓。综合来看,在气候变暖的背景下气温突变后高温日数增加要显著多于低温日数增加。过渡期日数变化趋势特征表明,严寒炎热过渡期、寒冷温暖过渡期和冷暖过渡期在突变后明显变短,生态功能区冷暖急转现象尤为明显。在历年尺度上,冷暖过渡期日数变化随着温度范围的扩大而减少幅度在加大。  相似文献   

15.
闫小月  姜逢清  刘超  王大刚 《冰川冻土》2022,44(5):1539-1557
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   

16.
大兴安岭区域未来气候变化趋势及其对湿地的影响   总被引:2,自引:1,他引:1  
基于未来2种排放情景下的RCM-PRECIS输出的大兴安岭区域气温与降水量预测数据,采用Mann-Kendall(简称M-K)非参数检验法和线性倾向率法,分析大兴安岭区域2015-2050年气候变化趋势及其对湿地的影响.结果表明,在未来2种情景下,2015-2050年的年平均气温升高显著,A2情景的增温速率(0.54℃·(10a)-1)高于B2情景(0.41℃·(10a)-1),与东北地区增温速率(0.56℃·(10a)-1)一致,B2情景增温速率低于东北地区增温速率;大兴安岭区域自2032年气温开始出现增暖突变现象,增温幅度显著增大.2种情景下季节平均气温的增温速率大小依次为夏季、冬季、春季和秋季,A2情景夏、冬、春、秋季分别为0.59、0.56、0.56、0.52℃·(10a)-1,B2情景分别为0.48、0.47、0.42、0.37℃·(10a)-1;各季突变增温时间点和增温趋势显著时段存在差异.2种情景下2015-2050年的年降水量有微弱的减少趋势,M-K检测基本无显著变化;季节降水总体而言,大兴安岭区域未来36a降水量仍以夏季为主,占全年降水量的60%左右;春季和秋季次之,各占全年降水量的18%~19%.未来大兴安岭区域气候呈现暖干化趋势,其中21世纪20、40年代大兴安岭湿地受到气候暖干化的胁迫相应较强,未来气候暖干化趋势是大兴安岭湿地生态系统萎缩和退化的主要诱因之一,未来大兴安岭湿地生态系统仍将受到气候暖干化趋势的巨大威胁,面临萎缩和严重退化趋势.  相似文献   

17.
冰川、积雪和冻土变化产生的水文效应对下游水资源供给具有重要影响,近几十年来新疆区域洪水呈显著加重趋势,尤其是南疆区域洪水明显加剧. 以天山南坡黄水沟与清水河寒区流域为研究区域,通过分析水文站极端水文事件,结合流域上游山区巴伦台气象站资料,研究了高寒山地流域在气候变化背景下极端水文过程出现时间、年最大和最小径流的响应特征. 结果表明:1986年是水文过程的突变点,从1986年开始随着降水、气温的增加,河流径流量呈增加趋势;最大年径流出现时间从6月中下旬推迟到7月下旬;最大径流和最小径流与年径流量呈正相关关系,最大径流与夏季降水关系密切,而最小年径流与冬春季的气温关系密切. 随着1986年以来的气温升高,冻土退化产生的水文效应使冬季径流增加明显,也使年最小径流明显增大;1986年以来降水变化决定着年径流量增加,使年最大径流集中出现在夏季且量级增大. 总体来讲,20世纪80年代中期以后山区河流年极端洪峰量增大,洪水量增多,年际间变化幅度明显增大,从而对下游造成更严重的灾害. 因此,加强气候变化对寒区流域水资源和洪水灾害的影响评估,使科学技术在减灾方面发挥主导作用.  相似文献   

18.
1961-2012年辽宁省极端气温事件气候变化特征   总被引:3,自引:1,他引:2  
利用辽宁省52个气象台站逐日平均气温、 最高气温和最低气温数据, 使用国际通用的10种极端气候指数, 研究了1961-2012年辽宁省极端气温事件的气候变化特征. 结果表明: 年平均极端气温事件空间分布存在明显的地区差异. 时间尺度上, 1961-2012年辽宁省年及四季极端暖事件(暖昼日数、 暖夜日数、 夏季日数、 热带夜数和热浪持续指数)呈增加趋势, 极端冷事件(冷昼日数、 冷夜日数、 结冰日数、 霜冻日数和寒潮持续指数)呈减少趋势; 极端暖事件在20世纪90年代中期开始明显增加, 极端冷事件在20世纪80年代末期开始显著减少; 极端暖事件的变化速率要小于极端冷事件. 辽宁省气温日较差有增大的趋势, 极端暖(冷)事件的增加(减少)在秋季(冬季)最为显著. 空间变化上, 极端气温事件在全省基本都呈一致的增加或减少的分布. 多数极端气温事件均存在8 a左右的周期, 检测到的突变的时间大致在20世纪80年代中期到90年代末期. 20世纪80年代末期辽宁省气候变暖后, 极端暖事件和冷事件均有明显的增加和减少.  相似文献   

19.
Daily data of minimum and maximum temperature from 76 meteorological stations for 1960–2010 are used to detect the annual and seasonal variations of temperature extremes in the arid region, China. The Mann–Kendall test and Sen estimator are used to assess the significance of the trend and amount of change, respectively. Fifteen temperature indices are examined. The temperature extremes show patterns consistent with warming, with a large proportion of stations showing statistically significant trends. Warming trends in indices derived from daily minimum temperature are of greater magnitudes than those from maximum temperature, and stations along the Tianshan Mountains have larger trend magnitudes. The decreases in frequency for cold extremes mainly occur in summer and autumn, while warm extremes show significant increases in frequency in autumn and winter. For the arid region as a whole, the occurrence of cold nights and cold days has decreased by ?1.89 and ?0.89 days/decade, respectively, and warm nights and warm days has increased by 2.85 and 1.37 days/decade, respectively. The number of frost days and ice days exhibit significant decreasing trends at the rates of ?3.84 and ?2.07 days/decade. The threshold indices also show statistically significant increasing trends, with the extreme lowest temperatures faster than highest temperatures. The diurnal temperature range has decreased by 0.23 °C/decade, which is in accordance with the more rapid increases in minimum temperature than in maximum temperature. The results of this study will be useful for local human mitigation to alterations in water resources and ecological environment in the arid region of China due to the changes of temperature extremes.  相似文献   

20.
基于新疆阿勒泰地区5个国家气象站的逐日平均气温、 最高气温和最低气温气象数据, 利用一元线性回归、 9 a滑动平均等方法分析了该地区近52年极端气温的时空变化规律。结果表明: (1)阿勒泰地区平均气温、 平均最高气温、 平均最低气温均显著上升, 上升速率为0.40、 0.29、 0.58 ℃·(10a)-1; 秋、 冬季上升幅度最大。(2)极端最高气温、 最低气温极高值、 暖昼、 暖夜以不同的速率上升(增加), 分别为0.19 ℃·(10a)-1、 0.58 ℃·(10a)-1、 1.45 d·(10a)-1、 3.37 d·(10a)-1。气温日较差以-0.29 ℃·(10a)-1的速率下降; 生长季长度呈上升趋势, 增加速率为3.31 d·(10a)-1。暖日、 暖夜在四季均呈上升趋势。除极端最高气温和生长季长度外, 其他指数均有50%以上的站点呈上升趋势。(3)极端最低气温、 最高气温极低值分别以0.68、 0.48 ℃·(10a)-1的速率上升; 冷昼、 冷夜、 冰日、 霜日均呈下降趋势, 减少速率分别为-1.57、 -3.69、 -1.79、 -4.40 d·(10a)-1。仅冷夜、 霜日两个指数在所有站点显著下降。(4)冷指数的减小幅度大于暖指数的增大幅度, 夜指数的减小幅度大于昼指数的增大幅度。  相似文献   

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