共查询到20条相似文献，搜索用时 31 毫秒
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Fei ZHENG Bo WU Lin WANG Jingbei PENG Yao YAO Haifeng ZONG Qing BAO Jiehua MA Shuai HU Haolan REN Tingwei CAO Renping LIN Xianghui FANG Lingjiang TAO Tianjun ZHOU Jiang ZHU 《大气科学进展》2023,40(4):541-548
The Northern Hemisphere(NH) often experiences frequent cold air outbreaks and heavy snowfalls during La Ni?a winters. In 2022, a third-year La Ni?a event has exceeded both the oceanic and atmospheric thresholds since spring and is predicted to reach its mature phase in December 2022. Under such a significant global climate signal, whether the Eurasian Continent will experience a tough cold winter should not be assumed, despite the direct influence of mid-to high-latitude,large-scale atmospheric ... 相似文献
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On August 5, 2001, Shanghai was struck by a torrential rainfall due to the passage of a tropical depression (TD). The rainfall intensity has been the strongest in recent 50 years. In this paper, a set of mesoscale re-analyses data and the planetary boundary layer observation from a wind profiler are used to understand the possible mechanism of such a heavy rain. Results show that the outburst of a southerly jet in the lower atmosphere triggered the explosive development of cyclonically vertical vorticity in the region with steep potential temperature surfaces in front of the TD; while the cyclonic vorticity increased notably at higher levels due to the small atmospheric vertical stability of westerly currents in the vicinity of Shanghai. The simultaneous sharp development of cyclonic vorticity at different levels should be the main cause for the torrential rainfall. 相似文献
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R. Iestyn Woolway John H. Simpson David Spiby Heidrun Feuchtmayr Ben Powell Stephen C. Maberly 《Climatic change》2018,151(2):333-347
Extreme weather can have a substantial influence on lakes and is expected to become more frequent with climate change. We explored the influence of one particular extreme event, Storm Ophelia, on the physical and chemical environment of England’s largest lake, Windermere. We found that the substantial influence of Ophelia on meteorological conditions at Windermere, in particular wind speed, resulted in a 25-fold increase (relative to the study-period average) in the wind energy flux at the lake-air interface. Following Ophelia, there was a short-lived mixing event in which the Schmidt stability decreased by over 100 Jm?2 and the thermocline deepened by over 10 m during a 12-h period. As a result of changes to the strength of stratification, Ophelia also changed the internal seiche regime of Windermere with the dominant seiche period increasing from ~?17 h pre-storm to ~?21 h post-storm. Following Ophelia, there was an upwelling of cold and low-oxygenated waters at the southern-end of the lake. This had a substantial influence on the main outflow of Windermere, the River Leven, where dissolved oxygen concentrations decreased by ~?48%, from 9.3 to 4.8 mg L?1, while at the mid-lake monitoring station in Windermere, it decreased by only ~?3%. This study illustrates that the response of a lake to extreme weather can cause important effects downstream, the influence of which may not be evident at the lake surface. To understand the impact of future extreme events fully, the whole lake and downstream-river system need to be studied together. 相似文献
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Reference emission scenarios in the literature have been the target of criticisms that suggest they convey too optimistic views on spontaneous energy-GDP decoupling of emerging countries economies. This article focuses on the case of India. It explores the role of current suboptimalities of the Indian power sector (structural under-investment in the sector leading to capacity shortage, power cuts and low efficiency) on future energy-GDP decoupling. To do so, it uses a hybrid general equilibrium framework, in which these suboptimalities are explicitly introduced. The results highlight that whether the constraints on investments in the power sector persist or not leads to contrasted trends in energy-GDP decoupling and GHG emissions. Over the short-term, capital scarcity in the power sector constrains the development of energy-intensive activities and therefore leads to higher energy-GDP decoupling. But on the longer-term, constrains on the power sector capacity limits substitution from fossil fuels to electricity, which entails both a low energy-GDP decoupling and a constraint on GDP growth when oil prices are high. The alleviation of suboptimalities appears thus as an insurance policy towards future oil price increase. 相似文献
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1资料分析处理分析宾县1961—2010年相关的气象资料,将50a资料,每10a划分为一个时段,共划分5个时段。即：61—70、71—80、81—90、91—2000、2001—2010年。 相似文献
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根据海阳1961—2010年气温、降水量、日照、相对湿度等气象资料,应用气候倾向率、Mann-Kendall 突变检测法、滑动t检验法,对海阳市气候变化及规律进行了分析。结果表明：历年平均气温、平均最高气温、平均最低气温、极端最低气温在过去的50a间呈显著的上升趋势,历年极端最高气温的上升趋势不显著,年代际变化特征突出;年降水量呈缓慢的减少趋势,变化趋势不显著,年代际间分布不均,变化较大,年降水量减少的原因是夏季和秋季降水减少;日照时数呈显著减少趋势,发生突变的时间点是2004年;年平均相对湿度呈现显著减少趋势,发生突变的时间点是1977年,秋季湿度减少最为明显。 相似文献
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根据册亨县1964~2003年共40 a的气温、降水资料,采用统计方法分析其变化特点,结果发现:在全球气候变暖的背景下,我县年平均气温以20世纪80年代中期为转折点,后20 a较前20 a增高了0.15℃,年平均气温的变化曲线呈波状上升;年降雨量也呈波状分布,旱涝交替。同样以80年代中期为转折点,前20 a雨水较为充沛,后20 a气候异常,干旱少雨。 相似文献
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The growth trajectory of hailstones in clouds determines the ground intensity and spatial distribution of hailfall. A systematic study of hail trajectories can help improve the current scientific understanding of the mechanisms by which hail forms in semi-arid regions of China and, in doing so, improve the quality of hail forecasts and warnings and help to prevent and mitigate disasters. In this study, the WRFv3.7.1 model was employed to provide the background field to drive the hailstone trajec... 相似文献
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X.-M. Zeng M. Zhao R.-C. Yu N.-S. Lin Y.-Q. Zheng L.-J. Zhang R.-J. Zhang 《Theoretical and Applied Climatology》2003,76(3-4):203-218
Summary ¶In order to better understand land-atmosphere interactions and increase the predictability of climate models, it is important to investigate the role of forest representation in climate modeling. Corresponding to the big-leaf model commonly employed in land surface schemes to represent the effects of a forest, a so called big-tree model, which uses multi-layer vegetation to represent the vertical canopy heterogeneity, was introduced and incorporated into the National Center for Atmospheric Research (NCAR) regional climate model RegCM2, to make the vegetation model more physically based. Using this augmented RegCM2 and station data for China during 1991 Meiyu season, we performed 10 experiments to investigate the effects of the application of the big-tree model on the summer monsoon climate.With the big-tree model incorporated into the regional climate model, some climate characteristics, e.g. the 3-month-mean surface temperature, circulation, and precipitation, are significantly and systematically changed over the model domain, and the change of the characteristics differs depending on the area. Due to the better representation of the shading effect in the big-tree model, the temperature of the lower layer atmosphere above the plant canopy is increased, which further influences the 850hPa temperature. In addition, there are significant decreases in the mean latent heat fluxes (within 20–30W/m2) in the three areas of the model domain.The application of the big-tree model influences not only the simulated climate of the forested area, but also that of the whole model domain, and its impact is greater on the lower atmosphere than on the upper atmosphere. The simulated rainfall and surface temperature deviate from the originally simulated result and are (or seem to be) closer to the observations, which implies that an appropriate representation of the big-tree model may improve the simulation of the summer monsoon climate.We also find that the simulated climate is sensitive to some big-tree parameter values and schemes, such as the shape, height, zero-plane displacement height and mixing-length scheme. The simulated local/grid differences may be very large although the simulated areal-average differences may be much lower. The area-average differences in the monthly-mean surface temperature and heat fluxes can amount to 0.5°C and 4W/m2, respectively, which correspond to maximum local/grid differences of 3.0°C and 40W/m2 respectively. It seems that the simulated climate is most sensitive to the parameter of the zero-plane displacement among the parameters studied. 相似文献
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近50a贵州气候变化分析 总被引：1，自引：4，他引：1
利用贵州省15个代表站1951～2000年的温度、降水资料,通过计算气候趋势系数、30a滑动平均和29a滑动均方差,研究了贵州各季及年平均温度、降水的长期变化趋势及气候基本态的变化特征和气候变率的长期变化,并用蒙特卡洛显著性检验方法对温度、降水的长期变化进行统计检验.研究指出近50a来贵州除春季降水显著减少外,各季及年平均温度、降水变化均不明显,属于自然振动. 相似文献
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利用1961—2010年库尔勒气象站年平均气温、年平均气压、年降水量、年平均地面风速、年沙尘日数、年沙尘暴日数及年日照时数等资料,分析了近50 a库尔勒市气候变化基本特征。分析表明:(1)近半个世纪来库尔勒市年平均气温上升速率为0.29℃/10 a,高于0.22℃/10 a的全国平均水平,与全球变暖的大背景相一致;(2)年降水量变化趋势不明显,但年际变率大;(3)年平均地面风速减小速率为0.25 m/s/10 a;(4)年沙尘日数、年沙尘暴日数都呈减少趋势,减少速率分别为14.3 d/10 a和0.77 d/10 a;(5)库尔勒年平均气压前期和后期较低、中期较高,年日照时数年际变化较大;(6)库尔勒的气温、年沙尘日数用Mann-kendall方法检验分别在不同年份发生了的突变。与同期相邻轮台站相比,年平均气温、年平均地面风速、年沙尘日数和年沙尘暴日数变化趋势存在明显不同,这可能和两地不同的城市化速度、绿程度有关。 相似文献
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根据文山州1961—2010年逐年气温、降水量、日照时数等资料,运用线性倾向估计、5 a滑动平均、M-K突变检验等方法计算分析了文山州近50 a各气象要素变化特征。结果表明:①年平均气温前20 a没有规律,后30 a全州均呈现出升温趋势。大部分站点在20世纪90年代初期发生突变,而在90年代末出现明显的升温趋势。②年平均最高气温从60—80年代大部分站点呈现升温的趋势,90年代后全州都呈现下降的趋势,21世纪初期全州又都呈上升趋势;各站点年平均气温发生突变时间不一致。③各个站点极端最高气温均出现多个突变点,年极端最高气温升温趋势没有年平均最高气温升温趋势明显。④近50 a来,各县年总降水量都有一个共性,即全都呈现出线性递减的变化,各县线性倾向率均为负值;年总降水量全州均在2000年后发生突变,但均未出现明显增加或减少的趋势;⑤近50 a来,文山州日照时数仅西畴和麻栗坡表现为增加的趋势,其余测站年总日照时数都在减少。 相似文献
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采用小波分析和滑动t检验等方法,对安阳市1961-2011年的降水资料进行分析研究,结果表明：1）安阳各站降水量变化趋势基本一致。夏季降水量和年降水量具有相同的变化趋势和位相,全市暴雨总日数变化与夏季降水量变化较一致,月降水量相对变率与月降水量百分比率在年内分布位相相反,最长连续有降水日数与最长连续无降水日数的年际变化基本上处于反相。2）安阳市降水日变化呈双峰双谷型,月降水量以7-8月为中心呈正态分布。3）春、秋、冬三季有效降水日数与降水量相关性较好,夏季降水量与暴雨日相关密切,暴雨对夏季降水量贡献显著。4）降水突变不明显。5）季、年降水量和降水日数存在多时间尺度特征,大尺度的周期变化嵌套着小民度的周期变化,不同的时间尺度对应的降水结构或日数增减不同。安阳市年降水量第1主周期为26a,年平均有效降水日数主周期为21a,暴雨日数主周期是19a,最长连续有（无）降水日数主周期是21a。 相似文献
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《湖北气象》2010,(4)
利用淮河流域159个气象台站1971—2009年逐日降水资料,统计出淮河流域历年各站暴雨量并建立时间序列,通过趋势分析、EOF分析、小波分析、MK突变检验等方法对暴雨量进行特征分析。结果表明:淮河流域常年暴雨量及暴雨次数空间分布非常一致,高值区位于流域西南部,暴雨量及暴雨站次呈单峰型分布,7月上、中、下三旬最为集中;全流域大部分地区的暴雨量呈现上升趋势,但未通过0.05的显著性检验;EOF前三个模态累积方差贡献为84%,第一模态全流域一致为正,表明暴雨量分布一致多或少;第二模态为南正北负,暴雨量分布北少(多)南多(少);第三模态为西正东负,暴雨量分布东少(多)西多(少);暴雨量2~3年高频震荡及12~14年低频震荡较为明显,在12~14年的时间尺度上经历了由多到少3个循环交替;暴雨量在2000年左右可能存在一次突变,2000—2009年年均暴雨量比1971—1999年年均值增加了52 mm。 相似文献