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对乌鲁木齐国际机场1984～2003年出现的典型雷暴天气过程,利用常规观测资料和机场跑道自动观测系统的实时观测资料,分析了机场雷暴天气的类型和雷暴天气下机场跑道附近气象要素演变及风切变,给出不同天气形势下机场雷暴的风切变特征。 相似文献
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基于2006—2015年西宁曹家堡机场的雷暴观测资料,从雷暴日（次）数、持续时间、初现方位、伴随天气现象和雷暴初终日特征方面对该高原机场的雷暴特征进行统计分析。结果表明,曹家堡机场年平均雷暴日数为34.7 d,主要发生在5—9月,夏季是该机场雷暴的集中爆发期;雷暴具有明显的日变化特征,集中发生在午后至夜间（16—22时）,持续时间在2 h以内;雷暴初现方位以偏西、偏北为主,偏西、偏北的对流云团发展是该机场飞行保障的关注重点;雷暴伴随天气现象以干雷暴和小阵雨为主,而少数伴有中、大阵雨的强雷暴主要发生在夏季;雷暴初终日平均间隔为173.2 d,并且初雷能充分体现该机场的典型雷暴特征。 相似文献
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《青海气象》2017,(4)
利用2006—2015年逐日气象观测资料,对机场预选址区域的温度、湿度、降水量、风向风速、能见度和灾害性天气等对机场选址有影响的天气气候条件进行了统计分析。研究结果表明,沈阳市浑南区作为机场预选址,降水具有明显的年变化和月变化特征,降水主要集中在6—8月份;主导盛行风向为SW,频率为12.4%,弱风和静风频率高,为53.5%;低能见度日数少,能见度条件好,出现500m的年平均日数为5.5d;灾害性天气较少,大风、雷暴、冰雹、暴雨、暴雪、扬沙和积雪年平均日数分别为0.5d、2.4d、0.1d、0.2d、0.1d、1.7d和7.4d,无沙尘暴天气发生。总体而言,沈阳市浑南区具备建设机场的优良天气气候条件,有利于机场工程设计及将来的航空飞行安全。 相似文献
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利用福州长乐机场1998—2015年雷暴观测资料、2010—2015年自动站观测资料及美国国家环境预报中心(NCEP)逐日再分析资料,对机场雷暴及其伴随的风切变天气特征进行统计分析。结果表明:长乐机场雷暴天气一年四季均有发生,夏季最为频繁,且持续时间较长;雷暴具有明显的日变化特征,主要出现在午后至傍晚,持续时间一般在2 h内,l h以内居多;长乐机场偏西方向是雷暴生成最多的方位。54%的雷暴发生前3 h至结束后3 h内伴有风切变,且偏西方向的雷暴伴有风切变的概率较大。长乐机场弱风切变出现的次数远高于中等强度风切变,而强风切变出现次数最少,且出现在偏西方向的概率较高。伴有风切变的雷暴天气主要有4种环流类型:南支槽型、华北槽型、副高控制型及热带气旋型。 相似文献
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统计分析机场所在地高青国家气象观测站近30a相关气候要素的逐时、逐日资料以及影响机场场址选择的天气气候条件,对可能影响高青通用机场建设的气象要素进行分析评估,结果表明:高青通用机场预选场址以东东北风(ENE)为主导风向,风力为轻风,强风天气多发生在春季3—4月;气温变化趋于平稳;降水主要集中在7—8月;能见度小于1000m的天气占全年的3.8%;雷暴、积雪、大风、闪电扬沙、冰雹等高影响天气事件均有发生,次数较少。高青通用机场预选场址区域内地形平坦,基本气象要素空间差异不大,气候特征均一,满足机场建设和运行的基本气候条件。 相似文献
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为了满足航空用户对于高效率高分辨率雷暴短期预报产品的需求,提出了一种基于对流云特征温度的雷暴解释预报算法。该算法根据模式资料计算得到对流云云顶和云底温度、-20℃层和-10℃层高度等要素,利用相关判据直接得到格点雷暴预报产品。利用2012 2014年中国35个机场的雷暴观测资料和同期美国全球预报系统(Global Forecast System,GFS)模式预报资料对该算法进行了检验,风险评分和技巧评分均表明该算法在上述机场具有较高的雷暴预报水平和正技巧,时间精度可达±1.5 h。同时利用2014年中国5个机场人工发布的终端机场天气预报(Terminal Aerodrome Forecast,TAF)与算法进行比较,结果表明:算法在较TAF至少提前8h发布的情况下,风险评分略低于TAF,探测概率达到或远高于TAF。该算法满足了目前航空用户对于高时间和高空间分辨率雷暴短期预报产品的需求。 相似文献
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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
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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
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Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration. 相似文献
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The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o. 相似文献
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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
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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
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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
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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
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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
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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