共查询到20条相似文献，搜索用时 31 毫秒
1.
E. Sh. Elizbarashvili M. E. Elizbarashvili N. B. Kutaladze I. Keggenhoff Sh. E. Elizbarashvili B. M. Kikvadze N. M. Gogia 《Russian Meteorology and Hydrology》2016,41(4):261-267
Using observational data from 50 weather stations in Georgia for the period of 1936-2013, the following climate indices of moisture regime are studied: maximum 1-day precipitation, maximum 5-day precipitation, the simple daily intensity index, the number of days with precipitation equal to not less than 10, 20, and 50 mm, number of consecutive wet and dry days. Geoinformation maps of the spatial structure are plotted, and the dynamics of these indices is studied for the period of global warming. Expected changes in the moisture regime in different physiographic regions in Georgia are assessed. 相似文献
2.
E. Sh. Elizbarashvili M. E. Elizbarashvili Sh. E. Elizbarashvili M. G. Pipiya L. G. Kartvelishvili 《Russian Meteorology and Hydrology》2020,45(1):58-62
The number of days with blizzard, the intensity, duration, periods of occurrence, and dynamics of blizzards in the mountain regions of Georgia are investigated using observational data from 20 weather stations. The features of wind and temperature regimes of blizzards are revealed. 相似文献
3.
E. Sh. Elizbarashvili M. E. Elizbarashvili Sh. E. Elizbarashvili N. B. Kutaladze N. Z. Chelidze V. E. Gorgisheli 《Russian Meteorology and Hydrology》2018,43(9):625-631
Based on observational data from 30 weather stations in Georgia for the period of 1936–2013, the geography, statistical structure, intensity, duration, and dynamics of tropical nights are investigated. The geoinformation map was constructed for the number of tropical nights for the WMO base period. The periods of occurrence and return of their different gradations and the regularities of long-term variations are revealed. 相似文献
4.
E. Sh. Elizbarashvili O. Sh. Varazanashvili N. S. Tsereteli M. E. Elizbarashvili Sh. E. Elizbarashvili 《Russian Meteorology and Hydrology》2012,37(2):106-111
The statistical structure of dangerous fogs with the visibility of less than 50 m is studied using the observation data of
50 meteorological stations in Georgia for the period of 1961–2006. The contribution of dangerous fogs to the total number
of foggy days is estimated. The number of days with dangerous fogs and their duration in different regions of the country
are determined and the empirical functions of their distribution, sizes of areas of their expansion, temperature regime, and
peculiarities of annual variations are studied. 相似文献
5.
利用东源县和紫金县国家气象站1978-2018年的逐日气象数据,分析了河源城区高温和炎热天气特征。结果表明:河源城区总高温日数、一般高温日数和重高温日数均呈明显增加趋势,无严重高温日。总高温日数存在4~5、8~9和准15年时间尺度的周期变化。常年首次在5、6月出现高温日;高温炎热日出现次数最多在7、8月份;极端年最高气温介于36.2~39℃。炎热日数以0.26 d/年速率明显增加,同一个炎热临界值,相对湿度增大,对应的最高气温会降低。炎热日数与热岛效应强度之间存在显著性的相关关系。高温炎热过程主要受副热带高压控制、热带气旋外围下沉气流和El Niňo事件影响。 相似文献
6.
E. Sh. Elizbarashvili O. Sh. Varazanashvili N. S. Tsereteli M. E. Elizbarashvili 《Russian Meteorology and Hydrology》2013,38(3):168-170
The statistical structure of hurricane winds is studied using the data of observation at 50 meteorological stations in Georgia for the period of 1961–2008. Determined are the number of days and the duration of hurricane winds in different regions of the country. Studied are the empirical functions of their distribution and the areal limits. 相似文献
7.
利用2005—2017年赤水国家气象观测站逐小时平均气温、相对湿度和10 min平均风速计算人体舒适度指数,对赤水人体舒适程度的气候特征进行了统计分析。结果表明,赤水舒适天气较多,存在少量的偏冷和炎热天气,酷热日数极少,具有显著的季节分布特征,具体为:①偏冷天气年日数在10～46 d之间波动,开始日期主要在12月份,占比85%,结束日期主要在2—3月份,偏冷天气出现在1月份的概率最大,一天中出现在04—11时的次数最多,出现在13—21时的次数较少;②酷热天气较少,仅出现6个时次,炎热天气年日数在16～54 d之间波动,在20～30 d的年度占比54%,炎热天气开始日期在6中旬—7月上旬,结束日期在8月中旬—9月下旬,一天中13—15时出现概率最大;③舒适天气年日数在135～176 d,年平均舒适天气152 d,4、5、9、10月是最舒适月份。研究表明,春秋季节较为舒适,适宜户外活动,也是赤水旅游的黄金期;冬季后半夜到上午易出现偏冷天气,夏季午后易出现炎热天气,户外活动时需要采取一定的防护措施。 相似文献
8.
东亚区域极端气候事件变化的数值模拟试验 总被引：62，自引：0，他引：62
使用ResCM2区域气候模式,嵌套澳大利亚CSIRO R21L9全球海气耦合模式,进行了温室效应（二氧化碳加倍）对东亚（主要是中国区域）极端气候事件影响的数值试验。控制试验的结果表明,区域模式能够较好地模拟中国区域的极端气候事件。对温室效应引起的它们的变化进行了信度检验,分析结果表明,温室效应将引起日最高和最低气温增加,日较差减小;使得高温天气增多,低温日数减少。降水日数和大雨日数在一些地区将增加。同时还会引起影响中国的台风活动的变化。 相似文献
9.
Changes of Climate Extremes in China 总被引：89，自引：0，他引：89
Changes in China's temperature and precipitation extremes have been studied by using observational data after 1950. The results reveal that mean minimum temperature has increased significantly in China during the past 40 years, especially in the winter in northern China. Meanwhile, nation-wide cold wave activity has weakened and the frequency of cold days in northern China has been reduced significantly. Mean maximum temperatures display no statistically significant trend for China as a whole. However, decreasing summer mean maximum temperatures are obvious in eastern China, where the number of hot days has been reduced. Seasonal 1-day extreme maximum temperatures mainly reflect decreasing trends, while seasonal 1-day extreme minimum temperatures are increasing.A statistically significant reduction of much above normal rain days in China has been detected. Contrarily, an increasing trend was detected in much above normal of precipitation intensity (precipitation/number of precipitation days) during the past 45 years. 相似文献
10.
11.
Yurdanur Sezginer Unal Elcin Tan S. Sibel Mentes 《Theoretical and Applied Climatology》2013,112(1-2):339-350
Global warming is one of the greatest environmental, economic, and social threats in the world. There are many assessments to estimate climate variability over many regions. A change in the Earth’s surface temperature leads to increase in extreme temperature events, which are harmful to the ecosystem, and moreover, they create danger on human health. In this study, we have selected the western part of Turkey as the study area, since climate change projections for Turkey point out that the highest temperature change can be expected on this region during summer, and the Turkish population is very dense here to be affected by extreme events. We have used apparent temperatures to define the heat waves which we have determined their frequencies for the summer months (June–August) of 1965–2006. Since the regional comparisons of station results are intended, we selected the 90th percentile value for each station as a threshold value to be used in the delineation of heat waves. Then, the number of heat waves is determined by imposing the constraint that apparent temperatures stay above the threshold value at least for three consecutive days. Then, the changes in the number of hot days and heat waves and also their durations are analyzed by using the linear least square method. We have found that the number of hot days, heat waves, and heat wave durations is increased between 1965 and 2006 on the western part of Turkey. Additionally, their rate of change is larger within the last decade and extremes are frequently observed after 1998. Regional distributions show that the tendency of the number of heat wave events increases towards the southern latitudes of the domain. Moreover, we investigated the relationship between the number of hot days and the sea surface temperatures of the Mediterranean Sea and Black Sea. Correlation analyses are carried out by the number of hot days and averaged sea surface temperatures on the regions of the western, central, and eastern Mediterranean Sea and the Black Sea. It is found that the number of hot days of west Turkey is better correlated with the sea surface temperatures averaged over eastern Mediterranean and Black Seas. The number of heat waves is found significantly correlated with the fire occurrences for most of the stations. 相似文献
12.
Coronato Tanea Carril Andrea F. Zaninelli Pablo G. Giles Julián Ruscica Romina Falco Magdalena Sörensson Anna A. Fita Lluis Li Laurent Z. X. Menéndez Claudio G. 《Climate Dynamics》2020,55(9-10):2543-2556
Based on a series of experiments conducted by two regional climate models (RCA4 and LMDZ) with and without soil moisture-atmosphere coupling, we investigate the role of soil moisture on the occurrence of surface air temperature extremes and its persistence in Southeastern South America. Our analysis reveals that both factors, soil moisture-atmosphere coupling and relatively drier soil conditions, enhance the temperature extremes. In addition, the existence of soil-atmosphere coupling and the associated soil moisture variability is crucial for the development of the extremes in SESA. The key role of soil-atmosphere coupling is also reflected in the intrinsic persistence of hot days, which is greater in simulations with interactive soil moisture than in those with prescribed soil conditions. In the absence of soil-atmosphere coupling, the imprint of the anomalous dry (and also wet) soil conditions on the intensity and persistence of hot days is weaker.
相似文献13.
The objective of this study was to analyze long-term temperature-related phenomena in the eastern portion of the Middle East, focusing on the coastal region of Qatar. Extreme temperature indices were examined, which were defined by the Expert Team on Climate Change Detection and Indices, for Doha, Qatar; these indices were then compared with those from neighboring countries. The trends were calculated for a 30-year period (1983–2012), using hourly data obtained from the National Climatic Data Center. The results showed spatially consistent warming trends throughout the region. For Doha, 11 of the 12 indices studied showed significant warming trends. In particular, the warming trends were represented by an increase in the number of warm days and nights and a decrease in the number of cool nights and days. The high-temperature extremes during the night have risen at more than twice the rate of their corresponding daytime extremes. The intensity and frequency of hot days have increased, and the minimum temperature indices exhibited a higher rate of warming. The climatic changes in Doha are consistent with the region-wide heat-up in recent decades across the Middle East. However, the rapid economic expansion, increase of population since the 1990s, and urban effects in the region are thought to have intensified the rapidly warming climate pattern observed in Doha since the turn of the century. 相似文献
14.
15.
Heatwaves in Europe: areas of homogeneous variability and links with the regional to large-scale atmospheric and SSTs anomalies 总被引：1，自引：1，他引：0
This work presents a methodology to study the interannual variability associated with summertime months in which extremely
hot temperatures are frequent. Daily time series of maximum and minimum temperature fields (T
max and T
min, respectively) are used to define indexes of extreme months based on the number of days crossing thresholds. An empirical
orthogonal function (EOF) analysis is applied to the monthly indexes. EOF loadings give information about the geographical
areas where the number of days per month with extreme temperatures has the largest variability. Correlations between the EOF
principal components and the time series of other fields allow plotting maps highlighting the anomalies in the large scale
circulation and in the SSTs that are associated with the occurrence of extreme events. The methodology is used to construct
the “climatology” of the extremely hot summertime months over Europe. In terms of both interannual and intraseasonal variability,
there are three regions in which the frequency of the extremely hot days per month homogeneously varies: north-west Europe,
Euro-Mediterranean and Eurasia region. Although extremes over those regions occur during the whole summer (June to August),
the anomalous climatic conditions associated with frequent heatwaves present some intraseasonal variability. Extreme climate
events over the north-west Europe and Eurasia are typically related to the occurrence of blocking situations. The intraseasonal
variability of those patterns is related to the amplitude of the blocking, the relative location of the action centre and
the wavetrain of anomalies downstream or upstream of the blocking. During June and July, blocking situations which give extremely
hot climate conditions over north-west Europe are also associated with cold conditions over the eastern Mediterranean sector.
The Euro-Mediterranean region is a transition area in which extratropical and tropical systems compete, influencing the occurrence
of climate events: blockings tend to be related to extremely hot months during June while baroclinic anomalies dominate the
variability of the climate events in July and August. We highlight that our method could be easily applied to other regions
of the world, to other fields as well as to model outputs to assess, e.g. the potential change of extreme climate events in
a warmer climate. 相似文献
16.
Changes in Canada's Climate: Trends in Indices Based on Daily Temperature and Precipitation Data 总被引：1，自引：0，他引：1
ABSTRACTTrends in indices based on daily temperature and precipitation are examined for two periods: 1948–2016 for all stations in Canada and 1900–2016 for stations in the south of Canada. These indices, a number of which reflect extreme events, are considered to be impact relevant. The results show changes consistent with warming, with larger trends associated with cold temperatures. The number of summer days (when daily maximum temperature >25°C) has increased at most locations south of 65°N, and the number of hot days (daily maximum temperature >30°C) and hot nights (daily minimum temperature >22°C) have increased at a few stations in the most southerly regions. Very warm temperatures in both summer and winter (represented by the 95th percentile of their daily maximum and minimum temperatures, respectively) have increased across the country, with stronger trends in winter. Warming is more pronounced for cold temperatures. The frost-free season has become longer with fewer frost days, consecutive frost days, and ice days. Very cold temperatures in both winter and summer (represented by the 5th percentile of their daily maximum and minimum temperatures, respectively) have increased substantially across the country, again with stronger trends in the winter. Changes in other temperature indices are consistent with warming. The growing season is now longer, and the number of growing degree-days has increased. The number of heating degree-days has decreased across the country, while the number of cooling degree-days has increased at many stations south of 55°N. The frequency of annual and spring freeze–thaw days shows an increase in the interior provinces and a decrease in the remainder of the country. Changes in precipitation indices are less spatially coherent. An increase in the number of days with rainfall and heavy rainfall is found at several locations in the south. A decrease in the number of days with snowfall and heavy snowfall is observed in the western provinces, while an increase is found in the north. There is no evidence of significant changes in the annual highest 1-day rainfall and 1-day snowfall. The maximum number of consecutive dry days has decreased, mainly in the south. 相似文献
17.
利用1967—2008年青藏高原68个台站逐日降水资料,按照《气象规范》对不同等级降水的定义,对青藏高原汛期（5—9月）不同强度的降水日数进行分析。结果表明：1967—2008年青藏高原汛期总降水日数及各强度降水日数均呈现出由东南向西北递减的空间分布特征,降水总日数和小雨日数以减少趋势为主,最显著的区域位于青藏高原东北和东南部,中雨日数以增加为主,大雨日数变化趋势的区域差异显著。青藏高原汛期各强度降水日数存在明显的年际变化,总降水日数的变化主要受小雨日数影响。汛期降水各旬分布上,各强度降水日数主要集中在夏季（6—8月）,小雨日数越少（多）的旬内其占总降水日数的比例就越大（小）,中雨和大雨日数越少（多）的旬内占总降水日数的比例就越小（大）;小雨和中雨日数均在1978年发生突变,突变前后,青藏高原东南部小雨和中雨日数差异最为明显。 相似文献
18.
利用1961-2017年成都市西部邛崃国家气象观测站日平均气温、日最高气温、日平均风速、日平均相对湿度和日最小相对湿度计算逐日人体舒适度指数及白天和夜间舒适度指数,并通过线性倾向估计方法分析近30年邛崃市人体舒适度变化特征。结果表明：近30年邛崃市没有暑热和寒冷天气,人体舒适度日数舒适级别日数最多,其次是冷不舒适级别日数,热不舒适级别日数最少;年平均人体舒适度指数呈现较小的上升趋势;舒适日数集中在春季、夏季、秋季三个季节;热不舒适日数和舒适日数21世纪初期相比20世纪90年代有所增加,冷不舒适日数有所减少;近30年白天人体舒适度指数有着较明显的升高趋势,夜间人体舒适度指数变化不大。 相似文献
19.
CHANGE TRENDS OF EXTREME CLIMATE EVENTS IN CHINA 总被引：5，自引：0，他引：5
The variations of extreme climate events such as cold wave, typhoon, hot and cold days havebeen discussed using the recent 45-year data. The reductions of nationwide cold wave activities andannual cold day number in northern China all have close relationship with warming winters,especially during 1980s and early 1990s. Decrements of annual hot day number are associated withcooling summers. The typhoon variation has connection with the tropical Pacific sea surfacetemperature conditions. The increments of drought/flood events since 1980s may be connectedindirectly with climate warming up significantly since 1980s. The climate variability of theseextreme climate events has decreased with time since 1980s. 相似文献
20.
E. Sh. Elizbarashvili O. Sh. Varazanashvili N. S. Tsereteli M. E. Elizbarashvili M. N. Kaishauri 《Russian Meteorology and Hydrology》2012,37(8):567-569
The peculiarities of wire icing in mountain areas of Georgia are investigated using the observational data of 14 meteorological stations of Georgia. Determined are the maximum frequency and the maximum mass of glaze-ice deposits, as well as the frequency of deposits of different mass and thickness. Considered are the effects of orography and meteorological conditions on the wire icing processes. 相似文献