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1.
这次防雹管理工作座谈会是根据年初领导小组会议决定,分两片召开的。6月14日至16日在洛川县召开了陕北片的会议,这次在陇县我们又召开了关中片的会议。这次会议经过三天的时间,传达了全国人工影响天气工作会议精神,学习了各省的人工影响天气管理办法,交流了管理经验,参观了陇县的石岭和曹家湾先进典型炮点,表彰了先进,研究了如何加强防雹工作。使代表们统一了思想,开阔了思路,提高了认识,增强了信心,大家决心会后进一步加强管理使防雹工作走上新台阶,争取获得更大的效益。会议开的很好,达到了预期的目的。会上,大家回顾了两年来防雹工作的进展,主要表现在以下几个方面: 1.对防雹工作的认识不断提高,各级 相似文献
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全国测报工作会议于去年10月13—19日在杭州召开,到会代表共131人,收到经验交流材料61份。 会议认真回顾了自1977年8月在太原召开的全国气象测报工作座谈会以来所进行的大量工作,这包括:1.深入揭批“四人帮”,不断肃清其在测报工作中的流毒;2.建立健全了规章制度,促进了工作的正常化;3.加强了在职测报人员的培训,提高了业务技术水平;4.开展了岗位练兵,苦练过硬本领;5.组织了测报大普查,恢复了检查工作制度;6.完成了地面观测规范的修改及组织执行;7.撤换了超检仪器,加强了检定工作;8.下发了保护观测环境的联合通知,改善了观测环境;9.整顿了台站档案,加强了记录报表的审核。由于五年来各级气象业务部门狠抓了以上各项工作,目前已经基本上扭转了十年内乱所造成的人员思想混乱,技术力量削弱,仪 相似文献
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介绍了雷电的形成．分析了产生雷电的天气形势。并在此基础上。概括了雷电预报的几种型式。设计了雷电预报的评分办法，提出了雷电预报服务的措施。 相似文献
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丛荣路 《沙漠与绿洲气象(新疆气象)》1996,(4)
近年来伊犁地区气象现代化建设迈出了可喜的一大步。1．开通了伊宁一乌鲁木齐气象有线通讯线路，改变了由邮电局转发气象电报的传统方式，提高了气象信息传输的速度、质量和时效，减轻了劳动强度，节省了人力物力。2．建立了局域网，即把州气象局的地面测报和预报等信息用微机联成网。开通了伊宁同乌鲁木齐、新源、昭苏间的微机远程终端，增加了预报产品及图表、资料的数量，提高了预报分析时效，尤其对灾害性、关键性天气预报的客观化、定量化提供了重要分析预报依据。3．建立了伊宁、新源、昭苏三县和伊宁市及农四师的农村气象科技服务网… 相似文献
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一、概况 4月28日凌晨及傍晚,我区出现了二次强对流天气全区普遍出现了8—10级大风,局部地区短时阵风达11级,87个公社出现了冰雹灾害,其中傍晚一次灾情最为严重,湖州市郊升山公社在17时35分左右下了拳头大小的冰雹,给工农业生产带来了重大损失。我们对这两次灾害性天气都作出了短时预报,特别在傍晚这次大范围的灾害性天气服务中,提前七小时发布了冰雹、大风、强降温的预报,又提前三个小时发了紧急警报,临时增加了一次广播,各级领导机关、工厂企业及广大农村都采取了抢险救灾的防范措施。因此,大大减少了人民生命财产的损失,收到了明显的经济效益。 相似文献
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综合气象观测系统的发展 总被引：9，自引：0，他引：9
回顾了气象探测发展史,分析了气象探测与气象预报、气象科学发展之间的紧密关系,指出了气象探测的发展推动了气象科学、气象预报和气象服务的发展;进一步描述了气象探测发展的现状,对于新技术的应用前景与气象仪器的未来发展趋势进行了分析与阐述,同时介绍了国际GCOS、GEOSS、WIGOS综合观测计划. 相似文献
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人工神经网络与遗传算法结合的时间序列预测模式 总被引：6，自引：1，他引：6
介绍了遗传算法的基本概念和流程，阐述了人工神经网络作为时间序列预测模式的可行性和不足之处，并提出了人工网络与遗传算法相结合的时间序列预测模式，最后给出了该算法的计算结果，并对结果和模式作了讨论。 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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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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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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Geophysical data sets are growing at an ever-increasing rate, requiring computationally efficient data selection(thinning)methods to preserve essential information. Satellites, such as Wind Sat, provide large data sets for assessing the accuracy and computational efficiency of data selection techniques. A new data thinning technique, based on support vector regression(SVR), is developed and tested. To manage large on-line satellite data streams, observations from Wind Sat are formed into subsets by Voronoi tessellation and then each is thinned by SVR(TSVR). Three experiments are performed. The first confirms the viability of TSVR for a relatively small sample, comparing it to several commonly used data thinning methods(random selection, averaging and Barnes filtering), producing a 10% thinning rate(90% data reduction), low mean absolute errors(MAE) and large correlations with the original data. A second experiment, using a larger dataset, shows TSVR retrievals with MAE < 1 m s-1and correlations 0.98. TSVR was an order of magnitude faster than the commonly used thinning methods. A third experiment applies a two-stage pipeline to TSVR, to accommodate online data. The pipeline subsets reconstruct the wind field with the same accuracy as the second experiment, is an order of magnitude faster than the nonpipeline TSVR. Therefore, pipeline TSVR is two orders of magnitude faster than commonly used thinning methods that ingest the entire data set. This study demonstrates that TSVR pipeline thinning is an accurate and computationally efficient alternative to commonly used data selection techniques. 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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宁波地区海-陆下垫面差异对雷暴过程影响的数值模拟 总被引：2，自引：0，他引：2
利用耦合Noah陆面过程的WRF模式对2009年6月5日傍晚发生在宁波地区的一次雷暴过程进行数值模拟,通过改变下垫面覆盖类型的敏感性试验,探讨了海洋和陆地下垫面对雷暴过程的影响。结果表明,WRF模式能够较合理地模拟出雷暴的发生、发展过程。雷暴发生前期,由于海-陆强烈的热力差异,海风特征明显,海风引起的抬升运动触发了雷暴,海风形成的强辐合区对应雷暴过程累积降水量的大值区。当研究区域全部被替换成陆地后,地表的粗糙度增大,在研究区域东部由于摩擦辐合加强,产生了强烈的上升运动,多个发展旺盛的对流单体在上升运动区生成,使雷暴产生的降水区域东扩、降水量增大、雷暴维持时间延长。当研究区域所有陆地被替换成水体后,白天地表通量减小,大气边界层中湍流运动减弱,边界层高度降低,大气层结变得稳定,不利于对流发展。 相似文献
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淮河流域水文极值预测模型研究 总被引：1，自引：0，他引：1
为探索气候变化影响下水文极值的非平稳性和预测方法,建立了水文极值非平稳广义极值（GEV）分布的统计预测模型。利用1952-2010年淮河上游流域累计面雨量和流量年最大值资料、同期500 hPa环流特征量资料以及17个CMIP5模式对环流特征量的模拟结果,筛选出对水文极值影响显著的年平均北半球极涡强度指数作为GEV分布参数的预测因子。分析了在RCP2.6、RCP4.5和RCP8.5情景下2006-2050年淮河上游流域水文极值对气候变化的响应。结果表明,10年以下与10年以上重现期的水文极值在非平稳过程中呈现前者下降而后者上升的相反变化趋势;多模型预测的集合平均在未来情景中均呈现上升趋势,情景排放量越大增幅越大,重现期越长增幅也越大。与极值的常态相比,极值的极端态更易受气候变化影响。 相似文献
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Light-absorbing particles in snow and ice: Measurement and modeling of climatic and hydrological impact 总被引：1，自引：0，他引：1
Yun Qian Teppei J. Yasunari Sarah J. Doherty Mark G. Flanner William K. M. Lau Jing Ming Hailong Wang Mo Wang Stephen G. Warren Rudong Zhang 《大气科学进展》2015,32(1):64-91
Light absorbing particles(LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance(a.k.a., surface darkening), which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice(LAPSI) has been identified as one of major forcings affecting climate change, e.g.in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high. In this review paper, we document various technical methods of measuring LAPSI and review the progress made in measuring the LAPSI in Arctic, Tibetan Plateau and other mid-latitude regions. We also report the progress in modeling the mass concentrations, albedo reduction, radiative forcing, and climatic and hydrological impact of LAPSI at global and regional scales. Finally we identify some research needs for reducing the uncertainties in the impact of LAPSI on global and regional climate and the hydrological cycle. 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