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1.
利用1992—2018年芜湖站逐小时降水量资料,统计分析不同量级短时强降水的变化特征,总结了四种类型短时强降水的物理量特征和风廓线雷达指标。结果表明,芜湖市短时强降水容易出现在夏季午后,2008—2018年中等强度的短时强降水更为频发。短时强降水发生时,可降水量较大,湿层较厚,副热带高压边缘型(以下简称"副高边缘型")短时强降水各指数明显偏强,比湿和假相当位温的垂直递减率较大,使得对流不稳定增强。低槽东移型和西北气流型短时强降水在发生前3—5 h有不同高度的西南风风速的增加,1 km以下水平风的"垂直切变"较大;副高边缘型和台风型短时强降水发生前后整层风速较小、"垂直切变"较小。在短时强降水的临近预报中,要充分考虑到不同天气类型下物理量和风廓线雷达指标的差异。 相似文献
2.
《青海气象》2017,(3)
通过对2006-2012年黄南州各地1h降水量≥25mm的短时强降水时空分布及环境场分析。结果表明:短时强降水时空特征为北少南多势态,河南最多,集中发生在7、8月份,一日的16-21时,均为单锋型;短时强降水过程的高空形势为副高边缘型、低涡切变型和西北气流冷平流型三种类型,其中副高边缘型强降水是黄南州主要高空环流形式,发生在冷锋前的暖区里;短时强降水天气过程开始前及发生时地面至中空湿度近似饱和,温度露点差小于4℃,触发短时强降水的冷空气侵入不同,副高边缘型温度场反应对流层中低层暖脊控制,对流层低层到地面有弱冷空气侵入,低涡切变型是对流层低层强冷空气的侵入,西北气流型是对流层中层冷空气入侵,对流层低层为暖空气控制;降水区一般在高空西风急流轴的南侧,高空西风急流出口区右侧存在辐散上升气流,有利于强对流天气的形成,低空显著气流为强降水区提供足够的水汽及不稳定层结的建立和维持;地面中尺度辐合线是强降水的中尺度影响系统;总结出短时强降水中尺度概念模型。 相似文献
3.
甘南高原大到暴雨天气过程分型及特征 总被引：1，自引：0，他引：1
基于2013—2016年甘南州181个区域站及自动站小时雨量观测资料,提取出53次大到暴雨天气过程,在此基础上进一步分析卫星云图、雷达观测资料以及历史天气资料。结果表明:甘南地区的大到暴雨天气过程主要出现在雨季,7、8月出现频次较高,其天气形势主要分为:西风槽型、副热带高压边缘型、低涡切变型、两高之间切变型、高压内部切变型5种类型,且以西风槽型为主。各类型大到暴雨天气过程的预报侧重点有所不同,西风槽型大到暴雨预报主要侧重于天气尺度环境场分析,其降水时间长,强度较弱(15 mm·h-1以下),副热带高压边缘型、低涡切变型、两高之间切变型大到暴雨天气的预报主要归结为对高原上短时强降水的预报,短时强降水的实时观测可为这三种类型大到暴雨天气过程的预报提供重要依据。 相似文献
4.
5.
淮河上游短时强降水天气学分型与物理诊断量阈值初探 总被引：2，自引：0，他引：2
利用常规高空、地面气象观测资料和NCEP 1°×1°再分析资料,对2001—2010年淮河上游短时强降水过程进行中尺度天气分析和物理量场诊断。然后,根据该区域短时强降水的环流形势和主要影响系统,将短时强降水过程分为副高边缘型、低槽型和台风倒槽型,其中副高边缘型又分为副高和低槽共同影响型、副高控制型和下滑槽副高型,归纳各类短时强降水天气系统配置模型,并提炼出表征短时强降水天气的物理量阈值。结果表明,淮河上游77.8%的短时强降水与西太平洋副热带高压有关,中低层多有急流、切变线和低涡,地面影响系统多为倒槽、辐合线和弱冷锋。短时强降水发生在低层辐合、高层辐散、低层正涡度以及中层上升运动的动力条件下;中低层有较强暖湿空气输送,湿区深厚,强降水发生在假相当位温(θse)大值区顶部;0℃层高度较高,中层风切变小,低层风切变较大,有利于短时强降水发生。 相似文献
6.
选取了甘肃平凉地区2015-2019年6-8月发生的27次短时强降水事件。利用自动站逐小时降水资料和高空探测资料,按照短时强降水阈值分类统计法和常规天气分析方法对甘肃平凉地区夏季短时强降水时空分布、影响天气系统及大气环境背景进行了统计分析。结果表明：6月短时强降水频次少,强降水高发区为六盘山山区;7月频次明显增多,活跃地区为静宁、崇信、泾川一带;8月频次及强度达到峰值,密集区为平凉北部的崆峒山区、崇信南部河谷地带。6月短时强降水日变化呈现单峰型特征,以午后居多,1 h降水量在20-30 mm段发生频次最高,占6月频次的80%以上;7月和8月日变化呈多峰型结构,夜间短时强降水频次增多,1 h降水量大于30 mm的频次显著增加,约占7月和8月总频次的40%。分析总结了平凉地区短时强降水天气类型,即高空低槽类、副热带高压类、西北气流类。另外,对表征动力、水汽、不稳定条件的环境参数统计分析,结果显示K指数、CAPE、T850-T500、Q850、θse-850等物理量平均特征值对平凉地区强降水预报有较好的指示意义。 相似文献
7.
利用东营2011—2018年自动气象站逐小时降水量资料,分析东营地区短时强降水的发生规律,包括短时强降水的空间分布和年、月、日以及强度变化特征。结果表明：东营地区短时强降水呈现西北部多南部少的分布特征;短时强降水年变化无明显规律,降水范围越大,出现次数越少;月分布呈单峰状,7—8月是多发月份,4—10月均有短时强降水发生;日变化呈波浪型,出现高峰时段在傍晚前后。东营地区产生短时强降水的天气系统可分为西风槽型、副高边缘型、切变线型、高空冷涡型、台风型等5种类型,其中切变线型出现次数最多,并给出了这5 种类型的天气学概念模型,同时得出不同范围和不同类型短时强降水过程关键环境参量的阈值。 相似文献
8.
利用1985-2018年汛期(5-9月)豫东地区20个国家站小时降水资料和2011-2018年同期豫东地区区域自动站观测数据、NCEP(1°×1°)再分析资料、高空地面观测资料等,统计分析了该区域小时雨强分别≥20mm/h、≥30mm/h和≥50mm/h的短时强降水时空分布特征,结果发现:豫东地区近34年汛期平均年降水量为458.9～577.5 mm/a,短时强降水次数为72.8次/a;2000年是短时强降水多发年份,≥20mm/h的雨强出现158次,是常年平均次数的1.17倍;主汛期的7-8月是不同强度短时强降水多发时期,34年来共计发生≥20mm/h的短时强降水1821次,占同强度短时强降水总次数(2476次)的近74.0%;在短时强降水的日变化中,05时是不同强度短时强降水多发时段,20时为次多发时段。对不同环流背景影响下短时强降水过程的水汽、动力、热力及能量等物理量作统计分析,低槽型短时强降水过程的动力条件优于其他两个类型的,850hPa涡度平均值达3.8×10~(-5)s~(-1),700hPa垂直速度平均值达-0.36 Pa·s~(-1);副高边缘型短时强降水过程不稳定能量条件优势显著,850hPa假相当位温平均值达354.1 K,500-850hPa假相当位温差的平均值达-17.80℃,K指数平均值为38.1℃、CAPE值平均值为2075.0 J·kg~(-1);而台风倒槽型短时强降水过程则在水汽输送方面更具优势,850 hPa比湿平均值为15.5g·kg~(-1),整层可降水量达70.0 mm。 相似文献
9.
贺兰山东麓宁夏一次极值暴雨过程分析 总被引：5，自引：1，他引：4
利用常规气象资料和NCEP再分析资料,结合宁夏业务化的中尺度数值预报模式MM5输出产品,对2006年7月14日发生在贺兰山东麓宁夏的极值暴雨过程从降水特征、环流背景、影响系统、强降水落区及物理量特征等方面进行了分析。表明:此次极值暴雨是在2006年第4号台风"碧利斯"与副热带高压系统的相互作用、中β尺度低值系统影响和地面静止锋的触发下爆发的。强降水落区位于200 hPa青藏高压前部西北气流辐散区与500 hPa西南气流、700 hPa西南或偏南低空急流、850 hPa偏东气流三股气流辐合区相重叠区,中β尺度低值系统的右前侧与湿焓平流最强的区域。对流层高层干冷空气下侵是强降水的主要触发机制之一。非地转湿Q矢量与强降水落区有良好的对应关系,对短时强降水天气具有较好的描述能力和预报指导意义。 相似文献
10.
2015年9月大气环流和天气分析 总被引：1，自引：1，他引：0
2015年9月环流特征如下：北半球高纬地区极涡为单极型,中高纬地区为3波型分布,西北太平洋副热带高压偏西且断裂,9月全国平均降水量为72.4 mm,比常年同期（65.3 mm）偏多14.0%;全国9月平均气温为16.9℃,较常年同期(16.6℃)偏高0.3℃。 月内共有6次强降水过程,24站出现了极端日降水量。西北太平洋和南海有4个台风生成,1517号台风基洛从中太平洋移入,1521号台风杜鹃两次登陆我国并带来大范围降水。西北东部及内蒙古中部等地气象干旱缓解,黄淮大部及辽宁等地气象干旱持续发展。全国多地遭受雷雨大风、冰雹等强对流天气袭击。 相似文献
11.
The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics. 相似文献
12.
Fei LIU Chen XING Jinbao LI Bin WANG Jing CHAI Chaochao GAO Gang HUANG Jian LIU Deliang CHEN 《大气科学进展》2020,37(7):663-670
正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment. 相似文献
13.
The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region. 相似文献
14.
Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms. 相似文献
15.
Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d. 相似文献
16.
Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region. 相似文献
17.
Yuepeng PAN Mengna GU Yuexin HE Dianming WU Chunyan LIU Linlin SONG Shili TIAN Xuemei Lü Yang SUN Tao SONG Wendell W. WALTERS Xuejun LIU Nicholas A. MARTIN Qianqian ZHANG Yunting FANG Valerio FERRACCI Yuesi WANG 《大气科学进展》2020,37(9):933-938
正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on 相似文献
18.
基于最新的GTAP8 (Global Trade Analysis Project）数据库,使用投入产出法,分析了2004年到2007年全球贸易变化下南北集团贸易隐含碳变化及对全球碳排放的影响。结果显示,随着发展中国家进出口规模扩张,全球贸易隐含碳流向的重心逐渐向发展中国家转移。2004年到2007年,发达国家高端设备制造业和服务业出口以及发展中国家资源、能源密集型行业及中低端制造业出口的趋势加强,该过程的生产转移导致全球碳排放增长4.15亿t,占研究时段全球贸易隐含碳增量的63%。未来发展中国家的出口隐含碳比重还将进一步提高。贸易变化带来的南北集团隐含碳流动变化对全球应对气候变化行动的影响日益突出,发达国家对此负有重要责任。 相似文献
19.
Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter. 相似文献
20.
Hourly outgoing longwave radiation(OLR) from the geostationary satellite Communication Oceanography Meteorological Satellite(COMS) has been retrieved since June 2010. The COMS OLR retrieval algorithms are based on regression analyses of radiative transfer simulations for spectral functions of COMS infrared channels. This study documents the accuracies of OLRs for future climate applications by making an intercomparison of four OLRs from one single-channel algorithm(OLR12.0using the 12.0 μm channel) and three multiple-channel algorithms(OLR10.8+12.0using the 10.8 and 12.0 μm channels; OLR6.7+10.8using the 6.7 and 10.8 μm channels; and OLR All using the 6.7, 10.8, and 12.0 μm channels). The COMS OLRs from these algorithms were validated with direct measurements of OLR from a broadband radiometer of the Clouds and Earth's Radiant Energy System(CERES) over the full COMS field of view [roughly(50°S–50°N, 70°–170°E)] during April 2011.Validation results show that the root-mean-square errors of COMS OLRs are 5–7 W m-2, which indicates good agreement with CERES OLR over the vast domain. OLR6.7+10.8and OLR All have much smaller errors(～ 6 W m-2) than OLR12.0and OLR10.8+12.0(～ 8 W m-2). Moreover, the small errors of OLR6.7+10.8and OLR All are systematic and can be readily reduced through additional mean bias correction and/or radiance calibration. These results indicate a noteworthy role of the6.7 μm water vapor absorption channel in improving the accuracy of the OLRs. The dependence of the accuracy of COMS OLRs on various surface, atmospheric, and observational conditions is also discussed. 相似文献