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1.
G. Drogue O. Mestre L. Hoffmann J.-F. Iffly L. Pfister 《Theoretical and Applied Climatology》2005,81(1-2):1-10
Summary Trends of monthly air temperature extremes were investigated in five meteorological stations of the Grand-Duchy of Luxembourg during the period 1949–1998. The application of an innovative homogenization method based on the concept of relative homogeneity to climatic time series allows identifying multiple break points, as well as correcting data series in an objective and robust statistical way. The rise of maximum temperature (Tmax) has occurred at a rate of 1.5 times that of the minimum temperature (Tmin) in winter (+1.4°C versus +0.9°C) and summer (+1.4°C versus +0.8°C). No trend in temperature extremes was found in autumn, while spring was affected by a small warming (+0.3°C) of Tmin and no change in Tmax resulting in a decrease of the diurnal temperature range (DTR) (–0.3°C). In spring, a strong positive linear relationship between Tmin warming and local terrain slope could be found. Comparison to new-gridded large-scale climatologies indicates generally close agreement to temperature trends during the 1949–1998 period, while a lower local warming was observed in summer during the post-1975 period following the changing-point year of atmospheric circulation over North-western Europe. This study shows that the question of data homogeneity is not trivial and should receive careful attention before quantifying historical temperature trends and identifying their spatial patterns at regional scale. 相似文献
2.
Summary ?The variability of the winter mean precipitation observed at 40 rainfall stations in Emilia-Romagna (a region in northern
Italy) from 1960 to 1995 is examined. The results are compared with those obtained for the whole of Italy using records from
32 stations. Temporal variability of the time series is investigated by means of Mann-Kendall and Pettitt tests, in order
to estimate the presence of trends and “change points”. Before analysis the original precipitation data set have been tested
to detect the inhomogeneity points, using the Standard Normal Homogeneity Test (SNHT). Almost all stations situated in Emilia
Romagna exhibit a significant decreasing trend in winter precipitation during the 1960–1995 period. The same characteristics
are revealed, more significant in the northern and central part of the region, when the stations for all Italy are analysed.
A significant downward shift in the winter precipitation is detected through the Pettitt test in Emilia Romagna, around 1980 at some stations, while the rest of the stations reveal the shift point occurrence around 1985. A significant downward shift in the winter precipitation is detected around 1985, when analysing the time series for all Italy. Spatial variability of winter precipitation is studied using the Empirical
Orthogonal Function. The first pattern indicates that a common large-scale process could be responsible for the winter precipitation
variability. The second EOF pattern shows an opposite sign of climate variability, which highlights the influence of relief
on the precipitation regime. The time series associated with the first precipitation pattern (PC1) at both scales emphasises
a significant decreasing trend and a downward shift point around 1985. The internal structure analysis of the North Atlantic
Oscillation (NAO) index during the 1960–1995 period reveals a significant increasing trend and an upward shift around 1980.
Strong correlation is also detected between PC1 (Emilia Romagna and at the scale of all Italy) and the NAO index. Thus, the
changes detected in the winter precipitation around 1985 could be due to an intensification of the positive phase of the [NAO],
especially after 1980.
Received March 23, 2001; revised February 20, 2002; accepted March 3, 2002 相似文献
3.
利用线性趋势法对1961-2008年阿勒泰地区7个气象站点气温日较差进行趋势研究,并根据各因子趋势值,应用相关统计法分析了影响气温日较差呈减小趋势的因子。结果表明：阿勒泰地区四季日较差呈现显著减小趋势,其中冬季最显著,秋季变化最弱。各季节最低气温上升趋势最明显,而最高气温上升趋势较弱。阿勒泰地区与月平均气温日较差相关性最强的因子是日照时数,呈正相关;其次分别为总云量、降水量和水汽压,都呈负相关。年气温日较差与降水量和水汽压相关性最大。 相似文献
4.
Summary Historical series of monthly mean temperatures from 27 Italian stations, updated to 1993, are analysed. Building on previous
analysis the following new results were obtained: there is an upward trend in seasonal and annual temperatures during the
last 20 years; a positive trend, stronger at southern stations compared to northern stations, is apparent from 1920 to 1950,
after when temperature shows no significant trend until 1985 when it starts to increase again. Data from Northern Italy show
similar characteristics to a subset of data from a global climatic database, for the period 1881–1988. This comparison, however,
suggests that good station coverage is important for the construction of a more detailed picture of seasonal climate variability.
Received February 19, 1998 Revised July 13, 1998 相似文献
5.
Summary Series of annual and seasonal temperature and precipitation representing respectively northern and southern Italy are compared
for trend, interannual variability and periodicity in the period 1866–1995. Temperature and precipitation trends are almost
always anticorrelated except in winter in the North where an anomalous behavior is evident till about 1980. The result is
that the Italian climate has become warmer and drier especially in the South since about 1930.The interannual variability
does not present significant maxima, but only minima that cannot be related tothe start of a trend either for temperature
or for precipitation. The power spectra of the series show broad significant peaks containing the quasi-biennial oscillation
and other well known periodicities probably due to solar cycles or to the North Atlantic ocean-atmosphere oscillation (NAO).
Received December 16, 1998 Revised October 21, 1999 相似文献
6.
夏季印度洋海盆模与MC区域降水异常联系的进一步分析 总被引：1，自引：0，他引：1
利用英国哈德莱中心的逐月海表温度资料及NCEP/NCAR月平均再分析资料等,通过在印度洋海盆模IOBM指数(IIOB)中扣除长期趋势和两类ENSO的同期信号后,得到了修正的IOBM指数(Im IOB),并由此分析了IOBM的变化及与海洋性大陆区域降水异常的联系。结果表明:印度洋IOBM为暖位相时,不同季节的印度洋地区均呈现异常偏暖,但大气是上升还是下沉运动则在印度洋不同季节和不同区域存在很大变化。就夏季而言,印度洋大部分地区存在上升运动,这与海温异常偏暖有关。在北半球夏季,指数Im IOB存在3~5 a的周期变化。当IOBM处于正位相时,印度洋至我国东海地区大范围海温偏暖。MC(Maritime Continent,海洋性大陆)区域西部降水正异常,而MC区域东北部降水为负异常。造成这种降水分布的原因是:当指数为正时,在MC区域的西部对流层低层辐合、高层辐散,上升运动增强,且水汽辐合,而MC区域的东北部对流层低层辐散、高层辐合,上升运动不明显,水汽辐散,不易形成降水。而在对流层低层与西太平洋辐散中心对应,南北半球出现关于赤道对称的反气旋对,赤道印度洋上的异常加热激发东传的Kelvin波,加强东风异常,同时加强了KMC(海洋性大陆的核心区域)之外南北半球热带地区的这对Rossby波型。以上这些结果有利于深刻理解MC降水异常成因及热带海陆气相互作用过程。 相似文献
7.
Summary ?A calendar of the negative and positive phases of the North Sea – Caspian Pattern (NCP) for the period 1958–1998 was used to analyse the implication of the NCP upper level teleconnections on the regional climate of the eastern Mediterranean basin. Series of monthly mean air temperature
and monthly total rainfall from 33 stations across Greece, Turkey and Israel, for the same period, were used. For each month,
from October to April, averages of the monthly mean temperatures and the monthly rainfall totals as well as the standardized
values of both parameters were calculated separately for the negative (NCP (−)) and the positive (NCP (+)) phases of the NCP.
At all stations and in all months, temperature values were significantly higher during the NCP (−) as compared with the NCP (+). Furthermore, apart from very few exceptions, the absolute monthly mean maximum and monthly mean minimum values were
obtained during the NCP (−) and the NCP (+) phases, respectively. The maximum impact of the NCP on mean air temperature was detected in the continental Anatolian Plateau, where the mean seasonal differences are around 3.5 °C. This influence decreases westwards and southwards.
The influence on the rainfall regime is more complex. Regions exposed to the southern maritime trajectories, in Greece and
in Turkey, receive more rainfall during the NCP (−) phase, whereas in the regions exposed to the northern maritime trajectories, such as Crete in Greece, the Black Sea region in Turkey, and in all regions of Israel, there is more rainfall during the NCP (+) phase. The accumulated rainfall differences between the two phases are over 50% of the seasonal average for some stations.
A comparison of the capabilities of the NCP, the North Atlantic Oscillation (NAO) and the Southern Oscillation (SO) indices to differentiate between below and above normal temperatures was made. The results have placed the NCP, as the best by far of all three teleconnections in its ability to differentiate between below or above normal temperatures
and as the main teleconnection affecting the climate of the Balkans, the Anatolian Peninsula and the Middle East. These results may serve to downscale General Circulation Model (GCM) scenarios to a regional scale and provide forecasts
regarding eventual temperature and/or precipitation changes.
Received June 25, 2001; revised February 25, 2002; accepted March 3, 2002 相似文献
8.
Summary Spatial-temporal characteristics of temperature variations were analyzed from China daily temperature based on 486 stations
during the period 1960–2000. The method of hierarchical cluster analysis was used to divide the territory into sub-regional
areas with a coherent evolution, both annually and seasonally. Areas numbering 7–9 are chosen to describe the regional features
of air temperature in mainland China.
All regions in mainland China experienced increasing trends of annual mean temperature. The trend of increasing temperature
was about 0.2–0.3 °C/10 yr in northern China and less than 0.1 °C/10 yr in southern China. In the winter season, the increasing
trend of temperature was about 0.5–0.7 °C/10 yr in northern China and about 0.2–0.3 °C/10 yr in southern China. The increasing
trend of autumn temperature was mainly located in northwestern China and southwestern China including the Tibetan Plateau.
In spring, the rising trend of temperature was concentrated in Northeast China and North China while there was a declining
temperature trend of −0.13 °C/10 yr in the upper Yangtze River. In summer, the declining trend of temperature was only concentrated
in the mid-low valley of the Yangtze and Yellow Rivers while surrounding this valley there were increasing trends in South
China, Southwest China, Northwest China, and Northeast China.
Rapid changes in temperature in various regions were detected by the multiple timescale t-test method. The year 1969 was a rapid change point from a high temperature to a low temperature along the Yangtze River
and South China. In the years 1977–1979, temperature significantly increased from a lower level to a higher level in many
places except for regions in North China and the Yangtze River. Another rapid increasing temperature trend was observed in
1987. In the years 1976–1979, a positive rapid change of summer temperature occurred in northwestern China and southwestern
China while a decreasing temperature was found between the Yellow River and the Yangtze River. A rapid increase of winter
temperature was found for 1977–1979 and 1985–1986 in many places.
There were increasing events of extreme temperature in broad areas except in the north part of Northeast China and the north
part of the Xinjiang region. In winter, increasing temperature of the climate state and weakening temperature extremes are
observed in northern China. In summer, both increasing temperature of the climate state and enhancing temperature extremes
were commonly exhibited in northern China.
Present address: Linfen Meteorological Office, Linfen 041000, Shanxi Province, China. 相似文献
9.
This study investigates the long-term spatiotemporal variability of diurnal temperature range(DTR) in East Africa(EA). The study carries out non-parametric trend analysis of gridded DTR monthly data sourced from Climatic Research Unit(CRU). The DTR exhibits mixed signals in space and time over EA. The DTR correlates negatively with rainfall over EA. Reduction in DTR coincides with the summer season in the northern and southern hemispheres respectively, suggesting the influence of cloud cover on it. There was a non-uniform pattern of DTR changes across the region with time. Lake Victoria basin recorded the highest warming rates. The Indian Ocean coast recorded the least spatiotemporal variability in DTR. A reduction in DTR is evident in the two seasons: hot and cold. The start of the study period; 1921—1930, was the coolest decade in the study period. Most parts of EA recorded negative DTR anomalies in 1961—1970. The overall reduction in DTR throughout the study period highlights the ongoing warming which is a global phenomenon. There remains need for investigating the causation of the observed DTR variability for effective monitoring of the variability in future. 相似文献
10.
本文选取西宁(城区)、湟中(南郊)、互助(北郊)3个气象观测站1986～2015年最高和最低温度资料,研究分析基于气温日较差的西宁热岛效应。结果表明,近30年城区、北郊年平均日较差总体呈下降趋势,下降幅度分别为0.15和0.29℃/10a,年代际分析表明21世纪10年代城区日较差距平偏低最多为0.73℃,日较差存在周末效应;城区日较差下降速率快于郊区,日较差变化趋势春季为正,其余各季为负,城区冬季变化显著,大于郊区;城区日较差逐渐减小,说明城市浑浊度逐年增加,热岛效应增强。 相似文献
11.
Changes of temperature extremes over China were evaluated using daily
maximum and minimum temperature data from 591 stations for the period
1961--2002. A set of indices of warm extremes, cold extremes and daily
temperature range (DTR) extremes was studied with a focus on trends. The
results showed that the frequency of warm extremes (F_WE) increased
obviously in most parts of China, and the intensity of warm extremes
(I_WE) increased significantly in northern China. The opposite
distribution was found in the frequency and intensity of cold extremes. The
frequency of high DTR extremes was relatively uniform with that of
intensity: an obvious increasing trend was located over western China and
the east coast, while significant decreases occurred in central,
southeastern and northeastern China; the opposite distribution was found for
low DTR extreme days. Seasonal trends illustrated that both F_WE and
I_WE showed significant increasing trends, especially over northeastern
China and along the Yangtze Valley basin in spring and winter. A correlation
technique was used to link extreme temperature anomalies over China with
global temperature anomalies. Three key regions were identified, as follows:
northeastern China and its coastal areas, the high-latitude regions above
40oN, and southwestern China and the equatorial eastern Pacific. 相似文献
12.
Diurnal temperature range (DTR) is an important index for climate because of its statistical relationships to greenhouse gases, urban heat, cloud cover, land use change, and aerosol haze layers. This study examines DTR trends across Zambia for the period 1930–2016 using the latest version of high-resolution monthly data (CRU TS v4.01) from the Climatic Research Unit. Non-parametric trend analyses were extensively employed at different spatial and temporal scales to quantify DTR changes. Taken together, results show a dominant east-west pattern with higher DTR values being observed in the western half of the country. Although there are noticeable differences in the magnitude from one month to the other, this east-west pattern is persistent throughout all the months. It is also found that mean annual DTR is negatively correlated with mean annual cloud cover with a strong and statistically significant coefficient of -0.8 but its correlation with precipitation weakens to -0.5 at the α 0.05. Results from the Mann-Kendall trend test shows marginal increments in DTR during all the seasons and they are all statistically significant at the α 0.05. The observed increments can be attributed to a general decrease in cloud cover over Zambia. 相似文献
13.
Spatial dependence of diurnal temperature range trends on precipitation from 1950 to 2004 总被引：2，自引：0，他引：2
Liming Zhou Aiguo Dai Yongjiu Dai Russell S. Vose Cheng-Zhi Zou Yuhong Tian Haishan Chen 《Climate Dynamics》2009,32(2-3):429-440
This paper analyzes the spatial dependence of annual diurnal temperature range (DTR) trends from 1950–2004 on the annual climatology of three variables: precipitation, cloud cover, and leaf area index (LAI), by classifying the global land into various climatic regions based on the climatological annual precipitation. The regional average trends for annual minimum temperature (T min) and DTR exhibit significant spatial correlations with the climatological values of these three variables, while such correlation for annual maximum temperature (T max) is very weak. In general, the magnitude of the downward trend of DTR and the warming trend of T min decreases with increasing precipitation amount, cloud cover, and LAI, i.e., with stronger DTR decreasing trends over drier regions. Such spatial dependence of T min and DTR trends on the climatological precipitation possibly reflects large-scale effects of increased global greenhouse gases and aerosols (and associated changes in cloudiness, soil moisture, and water vapor) during the later half of the twentieth century. 相似文献
14.
An analysis of simulated future surface climate change over the southern half of Korean Peninsula using a RegCM3-based high-resolution
one-way double-nested system is presented. Changes in mean climate as well as the frequency and intensity of extreme climate
events are discussed for the 30-year-period of 2021–2050 with respect to the reference period of 1971–2000 based on the IPCC
SRES B2 emission scenario. Warming in the range of 1–4°C is found throughout the analysis region and in all seasons. The warming
is maximum in the higher latitudes of the South Korean Peninsula and in the cold season. A large reduction in snow depth is
projected in response to the increase of winter minimum temperature induced by the greenhouse warming. The change in precipitation
shows a distinct seasonal variation and a substantial regional variability. In particular, we find a large increase of wintertime
precipitation over Korea, especially in the upslope side of major mountain systems. Summer precipitation increases over the
northern part of South Korea and decreases over the southern regions, indicating regional diversity. The precipitation change
also shows marked intraseasonal variations throughout the monsoon season. The temperature change shows a positive trend throughout
2021–2050 while the precipitation change is characterized by pronounced interdecadal variations. The PDF of the daily temperature
is shifted towards higher values and is somewhat narrower in the scenario run than the reference one. The number of frost
days decreases markedly and the number of hot days increases. The regional distribution of heavy precipitation (over 80 mm/day)
changes considerably, indicating changes in flood vulnerable regions. The climate change signal shows pronounced fine scale
signal over Korea, indicating the need of high-resolution climate simulations 相似文献
15.
Observed and projected climate change in Taiwan 总被引：1，自引：0，他引：1
Summary
This study examined the secular climate change characteristics in Taiwan over the past 100 years and the relationship with
the global climate change. Estimates for the likelihood of future climate changes in Taiwan were made based on the projection
from the IPCC climate models.
In the past 100 years, Taiwan experienced an island-wide warming trend (1.0–1.4 °C/100 years). Both the annual and daily temperature
ranges have also increased. The warming in Taiwan is closely connected to a large-scale circulation and SAT fluctuations,
such as the “cool ocean warm land” phenomenon. The water vapor pressure has increased significantly and could have resulted
in a larger temperature increase in summer. The probability for the occurrence of high temperatures has increased and the
result suggests that both the mean and variance in the SAT in Taiwan have changed significantly since the beginning of the
20th century. Although, as a whole, the precipitation in Taiwan has shown a tendency to increase in northern Taiwan and to
decrease in southern Taiwan in the past 100 years, it exhibits a more complicated spatial pattern. The changes occur mainly
in either the dry or rainy season and result in an enhanced seasonal cycle. The changes in temperature and precipitation are
consistent with the weakening of the East Asian monsoon.
Under consideration of both the warming effect from greenhouse gases and the cooling effect from aerosols, all projections
from climate models indicated a warmer climate near Taiwan in the future. The projected increase in the area-mean temperature
near Taiwan ranged from 0.9–2.7 °C relative to the 1961–1990 averaged temperature, when the CO2 concentration increased to 1.9 times the 1961–1990 level. These simulated temperature increases were statistically significant
and can be attributed to the radiative forcing associated with the increased concentration of greenhouse gases and aerosols.
The projected changes in precipitation were within the range of natural variability for all five models. There is no evidence
supporting the possibility of precipitation changes near Taiwan based on the simulations from five IPCC climate models.
Received February 5, 2001 Revised July 30, 2001 相似文献
16.
Summary Estimates of spring precipitation for the inner Alpine dry valley of the upper Inn (Tyrol, Austria) are made back to A.D.
1724 using a ring width chronology of Scots pine (Pinus sylvestris L.) as predictor. A highly significant agreement in year-to-year ring width changes exists between several chronologies along
the dry valley. The dendroclimatic model used for climate reconstruction is a simple linear transfer function that estimates
April–June precipitation from current tree-ring width. All verification statistics commonly used in dendroclimatological research
are significant ( p < 0.01) and indicate that the reconstructed time series provides valuable information on past spring precipitation variability.
Reconstructed spring rainfall deficiencies and surpluses ≥ 20% compared to the long-term mean in 1819, 1832, 1834, 1865, 1885,
and in 1780, 1782, 1821, 1853, 1910, respectively, are also documented by local historical records. Furthermore, a comparison
is made with an independent climate reconstruction based on historical weather indices valid for the northern side of the
Swiss Alps. A fairly good agreement is found between both spring rainfall reconstructions at low frequency intervals during
1755–1862 and 1919–1981. This preliminary study shows that tree-rings can be used to reconstruct spring rainfall variability
for inner Alpine dry valleys.
Received December 18, 2000 Revised May 28, 2001 相似文献
17.
基于多维集合经验模态分解方法,利用CRU全球地表气温日较差、最高气温和最低气温资料,开展对1951～2019年全球地表气温日较差长期趋势的演化研究.结果表明:全球地表气温日较差主要呈现下降趋势,并以北半球中高纬度地区为甚,空间差异性较大.全球地表最高气温和最低气温的长期演化趋势则主要表现为上升,且最低气温更为剧烈.从纬... 相似文献
18.
19.
Abstract Trends in Canadian temperature and precipitation during the 20th century are analyzed using recently updated and adjusted station data. Six elements, maximum, minimum and mean temperatures along with diurnal temperature range (DTR), precipitation totals and ratio of snowfall to total precipitation are investigated. Anomalies from the 1961–1990 reference period were first obtained at individual stations, and were then used to generate gridded datasets for subsequent trend analyses. Trends were computed for 1900–1998 for southern Canada (south of 60°N), and separately for 1950–1998 for the entire country, due to insufficient data in the high arctic prior to the 1950s. From 1900–1998, the annual mean temperature has increased between 0.5 and 1.5°C in the south. The warming is greater in minimum temperature than in maximum temperature in the first half of the century, resulting in a decrease of DTR. The greatest warming occurred in the west, with statistically significant increases mostly seen during spring and summer periods. Annual precipitation has also increased from 5% to 35% in southern Canada over the same period. In general, the ratio of snowfall to total precipitation has been increasing due mostly to the increase in winter precipitation which generally falls as snow and an increase of ratio in autumn. Negative trends were identified in some southern regions during spring. From 1950–1998, the pattern of temperature change is distinct: warming in the south and west and cooling in the northeast, with similar magnitudes in both maximum and minimum temperatures. This pattern is mostly evident in winter and spring. Across Canada, precipitation has increased by 5% to 35%, with significant negative trends found in southern regions during winter. Overall, the ratio of snowfall to total precipitation has increased, with significant negative trends occurring mostly in southern Canada during spring. Indices of abnormal climate conditions are also examined. These indices were defined as areas of Canada for 1950–1998, or southern Canada for 1900–1998, with temperature or precipitation anomalies above the 66th or below the 34th percentiles in their relevant time series. These confirmed the above findings and showed that climate has been becoming gradually wetter and warmer in southern Canada throughout the entire century, and in all of Canada during the latter half of the century. 相似文献
20.
The Freezing Precipitation over the Middle-Lower Reaches of the Yangtze River during February-March 2009 
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下载免费PDF全文 In this paper, the authors analyze the quasistationary fronts, surface conditions, and atmospheric stratification processes associated with a freezing precipitation event over the middle-lower reaches of the Yangtze River, especially in the Dabie mountain during February-March 2009. The long duration of freezing precipitation was primarily caused by stationary and anomalous synoptic weather patterns, such as a blocking high pressure in the northern branch and a trough in the southern branch of the westerlies, which resulted in the encounter cold air from northern China and warm moisture from the south. The east-west-oriented, quasi-stationary front （or shear line） found in central China was mostly responsible for producing the precipitation. The warm layer and nearsurface frozen layer were located in the lower troposphere along the front zone. Although the warm layer （〉 0℃） existed along the whole front, a surface temperature less than 0℃ appeared only over the lower-middle reaches of the Yangtze River, especially in the Dabie mountain. Therefore, the surface temperature was the main influencing factor, as the freezing precipitation only happened over the Dabie mountain. 相似文献