Can Eurasia Experience a Cold Winter under a Third-Year La Ni?a in 2022/23?

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 ...     

Mesoscale Diagnosis of a Torrential Rainfall Caused by a Tropical Depression

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.     

Physical and chemical impacts of a major storm on a temperate lake: a taste of things to come?

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.     

呼伦贝尔50a白灾分析

利用呼伦贝尔16个国家级气象观测站1960-2010年最大积雪深度、最长连续积雪日数、总积雪日数等资料,计算呼伦贝尔地区1960-2009年各个地区的白灾指数。经过计算,2003—2004年是呼伦贝尔各地出现白灾最多的年份,2000年以后呼伦贝尔白灾有加重的趋势。受下垫面影响,西南部牧区的西旗,50 a出现白灾次数最多,共出现18次,达2.8 a一遇;呼伦贝尔林区白灾出现频次最少。根据呼伦贝尔白灾次数分布图可直观看出,西南部和东南部是白灾的高发区,上述地区是需要重点防范的地区。     

册亨县40a气候变化分析

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。     

Energy-GDP decoupling in a second best world—a case study on India

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.     

宾县50a气候变化分析

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。     

海阳50a气候特征分析

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。     

Classification of Hailstone Trajectories in a Hail Cloud over a Semi-Arid Region in China

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...     

Application of a “Big-Tree” model to regional climate modeling: a sensitivity study

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.     

加格达奇近38a气候变化特征分析

本文利用加格达奇气象观测站气温、降水、霜冻、积温和大风资料,对加格达奇有记录以来38 a的气候变化进行分析,结果表明:气温呈上升趋势,降水总趋势减少,20世纪90年代之后,气温异常偏暖的机率明显增加,积温增多明显,冬季增温幅度最大,霜期变化与全球变暖趋势基本一致,但是90年代之后,0℃终霜有拖后趋势,大风日数有明显减少的趋势,极端天气事件明显增多。     

毕节地区近50a气候变化特征

根据毕节地区1959～2004年近50a的平均温度、降雨量以及极端气温进行线性趋势和5a滑动平均分析，找出气候变化特征，有助于农业生产趋利避害。     

近50a贵州气候变化分析

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.     

库尔勒近50a气候特征分析

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。     

安顺市40a倒春寒灾害统计分析

用统计方法对安顺市40 a(1971—2010年)的倒春寒进行了分析,得出各种倒春寒灾害出现的大致机率,并经过初步分析和应用他人对贵州倒春寒的科研成果,给出安顺市倒春寒灾害的环流背景和主要影响系统。     

敦煌近56a气候特征分析

利用1954～2009年敦煌国家基准气候站56a的气温、降水量、日照时数资料,分析了敦煌年平均气温、降水量、日照时数变化特征,初步探讨了敦煌干旱化气候特征以及对敦煌莫高窟文物的影响。结果表明:气温变化逐年升高,降水量总体呈增加趋势,日照时数变化相对稳定且略有增多趋势。虽然降水有所增多,但温度上升、日照增多导致蒸发增大,干旱化趋势明显。干旱气候变化有利于敦煌莫高窟的保护。     

安顺市近45a气候变化分析

利用安顺市6个地面观测站1961-2005年月平均气温和降量资料,对年和四季的基本气候特征、年代际变化、气温和降水异常年、气候突变等进行了分析。结果表明,近45a来安顺市气候变化存在较明显的季节性差异。除春季外,年和各季平均气温呈上升趋势,秋、冬季升温明显,但未出现突变现象。夏季和冬季降水有增加趋势,而春季和秋季降水呈减少的趋势。秋季降水存在由多到少的突变现象,自20世纪80年代以来秋绵雨出现的天数也呈现出明显的下降趋势。气温异常偏高年的次数远多于异常偏低年,降水异常偏少年多于异常偏多年。     

近50a开封市气候变化特征分析

利用开封市气象观测站1957-2007年的观测资料,分析了近50 a气候变化的特征,结果表明:开封市年平均气温呈上升趋势,春季气温呈波浪式平缓上升,夏季气温略有下降,秋季气温缓慢上升,冬季气温上升明显;年平均降水量变化趋势不明显,年际波动大,夏季降水呈上升趋势,冬春降水变化不明显,秋季降水下降明显;历年大风日数呈V型上升趋势,夏季上升明显,秋冬两季略有下降;年平均大雾日数呈明显上升趋势;年平均日照时数呈下降趋势,2000年后日照时数下降明显.     

察右中旗近50a气候变化特征分析

利用察右中旗1961-2010年的地面观测资料,对气温和降水的气候平均值特征和变化趋势进行了统计分析,并根据统计结果探讨引起当地气候变化的可能原因.在此基础上,还对旱涝情况进行了分析.分析表明:(1)近50a来察右中旗的年平均气温呈明显的上升趋势,1989年后上升幅度达0.67℃.(2)降水量季节分布不均匀,近50a来降水总量有减少的趋势,减幅明显,达14mm.年降水总量在年际之间差别较大,最多的年份可为最少的年份的2～3倍,旱年数多于涝年.(3)全球的气候变化和当地生态的人为改变是造成气温升高的可能因素.