云分析图的制作及其说明

一、引言 云分析图又叫云层分析图。它是在运用预报经验对卫星云图进行分析的基础上研制的,是用若干种符号代表卫星云图图象信息的一种图。这种图有利于提高卫星云图的利用率和传输,可供广大气象台站和其它部门使用。     

对华北地区夏季几种雷暴的分析

雷暴是华北地区夏季重要的天气现象之一,对飞行安全有很大影响,因此雷暴预报是天气预报工作的一项重要内容。我们把卫星云图应用于雷暴预报方面还刚刚开始,又因为我们收的是极地轨道卫星云图,两张云图之间相隔时间较长,所以单独用卫星云图资料来进行生命极短的雷暴预报,目前还有一些困难。本文对雷暴的分析还是采用天气图资料和卫星云图资料相结合的方法。     

(四)用卫星云图估计降水

前面两讲介绍了卫星云图的识别原理和几种天气系统的分析方法,这些都是利用卫星云图作定性分析。除此而外,利用卫星云图也可以作多种气象要素的定量分析。如:用红外云图推算海面温度、云顶温度和云顶高度;估计台风中心的最大风力;改进500毫巴的数值分析;估计降水量等等。本讲着重介绍如何用卫星云图估计降水。 目前用于估计降水的气象卫星资料主要有三种:即电视云图、两通道(0.5—0.7微米和8—12微米)扫描辐射仪云图和电子微波(1.55厘米)扫描辐射仪云图。就估计降水的方法而言,主要有三类。 第一类是建立在图象显示云图的基础上,根据卫     

对提高卫星云图清晰度的一些体会

近年来,随着卫星云图在天气分析、予报、研究方面的广泛应用,对卫星云图的接收质量提出了进一步的要求。 卫星云图接收质量的高低,从对云的结构分析来讲,最重要的是看云图的清晰度,清晰度直接影响到云图的使用效果,因此,清晰度是卫星云图接收质量高低的主要标志。 怎样来提高卫星云图的清晰度呢?首先要弄清什么才算是清晰度好的云图,其次,要弄清影响卫星云图清晰度的主要因素。     

暴雨分级卫星云图模型和模式识别

详细分析了1982年与1998年各种暴雨过程的卫星云图，归纳出了暴雨分级卫星云图模型。对卫星云图模型进行了图象处理，提取出了卫星云图模型的纹理、结构、灰度等特征，用统计与句法相结合的方法进行模式识别，效果良好。     

用台风云团特征系数预报南海北上台风西折的尝试

卫星云图在天气分析、预报和研究工作中正在发挥着积极的作用,它已经成为我们制作日常天气预报的有效工具。我台接收、分析和使用卫星云图资料已八年有余,分析方法还停留在定性阶段,这影响着卫星云图资料的进一步使用。能否在现有条件下,用一个量的概念来描述卫星云图呢?它的效果又如何?带着这样的问题,首先在台风路径预报中试了一试,有一定效果,于是就引出了下面的内容。     

云的卫星探测和飞机探测

一、卫星云图的原理 气象卫星云图是在高空俯视较大范围的云景图片。初期是电视云图。这种云图是卫星携带照相机,在空间轨道上,向下对地球大气进行照相,然后分解成许多扫描线变成电信号向地面发送,地面站得到一张张平面图象。由于夜间无法照相,只有白天的云图。随着卫星技术的发展,第二代业务卫星则用扫描     

运用卫星云图分析图作汛期降雨预报

卫星云图分析图是卫星云图经过分析后绘出的云实况图。这种图具有直观、清晰、定时、连续的特点,特别适合无云图判读经验的县站预报员使用。目前一般县站都可以接收日本播发的卫星云图分析图。宜山站从1985年汛期开始接收该图,用来作汛期降雨预报的辅助用图,收到较好的效果。现将我们的使用方法介绍如下。     

卫星云图和航空保障

卫星云图对于航空保障很有用处。下面简单介绍一下我们的使用情况。 一、用卫星云图直接为飞行服务 1.作为气象文件提供机组在飞行中使用:在所有的气象文件中,飞行员最喜欢的是卫星云图,特别是作远距飞行、跨洋飞行以及有台风的时候。这是因为在一定的空间内,卫星云图较之其他气象资料,有直观、形象、准确、具体等优点。因此,在国际航空气象服务程序中把云图(卫星云图、雷达云图)列为必备资料。     

冰雹的卫星云图特征识别和外推预报

对湖北省1979－1999年的冰雹过程的卫星云图进行了分析，总结出冰雹过程的卫星云图特征，用统计模式识别方法进行了识别，在对红外云图进行图象处理后，用交叉匹配方法得到其移动矢，以此对冰雹云系做外推预报，结果表明，其准确率比主观识别方法的要高。     

Local Meteorological and Synoptic Characteristics of Fogs Formed over Incheon International Airport in the West Coast of Korea

Fogs observed over Incheon international airport (IIA) in the west coast of Korea from January 2002 to August 2006 are classified into categories of coastal fog, cold sea fog, and warm sea fog based on the areal extent of the fogs and the difference between the air temperature (T) and the SST, i.e., cold sea fog if TSST = T-SST>0^oC and warm sea fog if TSST <0^oC. The numbers of coastal, cold, and warm sea fog cases are 64, 26, and 9. Coastal fogs form most frequently in winter, while cold sea fogs occur mostly in summer and warm sea fogs are observed from January to May but not in November and December. On average the air gets colder by 1.6^oC during the three hours leading up to the coastal fog formation, and an additional cooling of 1.1^oC occurs during the fog. The change in the dew point temperature (T_d) is minimal except during the fog (0.6^oC). Decreases in T for the cold and warm sea fogs are relatively smaller. The average T_d is higher than SST during the cold sea fog periods but this T_d is more than 4^oC higher than that for the corresponding non-fog days, suggesting that cold sea fogs be formed by the cooling of already humid air (i.e., T_d>SST). Increases of T_d are significant during the warm sea fog periods (1.4^oC), implying that efficient moisture supply is essential to warm sea fog formation. Four major synoptic patterns are identified in association with the observed fogs. The most frequent is a north Pacific high that accounts for 38% of cases. Surface or upper inversions are present in 77%, 69%, and 81% of the fog periods for coastal, cold, and warm sea fogs, respectively.     

2009年春季一次黄海海雾的观测分析及数值模拟

利用5种观测资料和RAMS（regional atmospheric modeling system）模式对2009年5月2_5日发生在黄海海域的一次海雾过程进行了观测分析和数值模拟研究。结果表明：1）所取个例的整个生命过程受同一高压系统影响,该高压在海雾过程后期的形变促使海雾消散,这在以往的黄海海雾中较为罕见。2）黄海北部形似“7”的雾区形态的出现和演化与1～3℃气海温差的变化吻合,气海温差对海雾形成和演变的重要作用得到再次验证。3）RAMS模式具有一定的海雾数值模拟能力,得到的雾顶高度分布与卫星云图所显示的雾区形态吻合良好。     

海陆交界处平流辐射雾的二维数值模拟

本文采用二维非定常数值模式,模拟了大气边界层内海陆交界处的平流辐射雾的形成和演变规律。在模式中考虑了平流、辐射及湍流等物理因子及其相互作用。模拟结果表明,夜间盛行风将暖湿空气带入陆地,水汽经辐射冷却形成雾,地面陆风环流起了一定作用。      

长三角地区11月大雾频次变化的天气气候背景

采用1977—2006年长三角地区5个国家气候一级站的1日4次地面气象观测资料以及NCEP/NCAR相关资料,初步分析了该地区11月区域雾频次变化的天气气候背景。结果表明,长三角11月区域雾少发（多发）时,500hPa高空为较强的西北风（平直的西风）,850hPa上为强西北风（弱西北、东北风）,低层925hPa上偏北风分量较大且相对湿度较小（偏北风减小并出现偏东风分量且相对湿度较大）,海平面气压场上长三角受强冷高压控制（位于弱高压底前部均压区内）。     

The chemical composition of fogs and intercepted clouds in the United States

Over the past decade, the chemical compositions of fogs and intercepted clouds have been investigated at more than a dozen locations across the United States. Sampling sites have been located in the northeast, southeast, Rocky Mountain, and west coast regions of the US. They include both pristine and heavily polluted locations. Frontal/orographic clouds (warm and supercooled), intercepted coastal stratiform clouds, and radiation fogs have all been examined. Sample pH values range from below 3 to above 7. Major ions also exhibit a wide concentration range, with clouds at some locations exhibiting high sea salt concentrations, while composition at other locations is dominated by ammonium and sulfate or nitrate.     

Microphysical characteristics of sea fog over the east coast of Leizhou Peninsula, China

Microphysical properties of sea fog and correlations of these properties were analyzed based on the measurements from a comprehensive field campaign carried out from 15 March to 18 April 2010 on Donghai Island (21°35’’N, 110°32’5’’E) in Zhanjiang, Guangdong Province, China. There were four types of circula- tion pattern in favor of sea fog events in this area identified, and the synoptic weather pattern was found to influence the microphysical properties of the sea fogs. Those influenced by a warm sector in front of a cold front or the anterior part of low pressure were found to usually have a much longer duration, lower visibility, greater liquid water content, and bigger fog droplet sizes. A fog droplet number concentration of N≥1 cm-3 and liquid water content of L≥0.001 g m-3 can be used to define sea fogs in this area. The type of fog droplet size distribution of the sea fog events was mostly monotonically-decreasing, with the spectrum width always being >20 μm. The significant temporal variation of N was due in large part to the number concentration variation of fog droplets with radius <3 μm. A strong collection process appeared when droplet spectrum width was >10 μm, which subsequently led to the sudden increase of droplet spectrum width. The dominant physical process during the sea fog events was activation with subsequent condensational growth or reversible evaporation processes, but turbulent mixing also played an important role. The collection process occurred, but was not vital.     

沪宁高速公路大雾及气象要素特征分析

利用2006年6月-2009年5月沪宁高速公路AWM自动气象站资料,研究了不同类型大雾持续时间、能见度变化及其出现过程中风、湿度变化特征。结果表明,有超过50%的大雾会发展成浓雾;大雾持续时间以平流雾最长,辐射雾最短;67.6%的大雾在长时间低能见度之前会出现类似"象鼻"形的突变前兆,这可能与地理环境有关;大雾过程中风向以东风和西风为主,锋面雾有部分为偏南风;平流雾发生时风速较辐射雾和锋面雾大,锋面雾发生时风速较多为静风,结束时风速快速增大;平流雾发生时相对湿度多有突变,而辐射雾、锋面雾的相对湿度以渐变为主。     

我国近年雾研究方法及研究热点综述

在过去的几十年里,我国关于雾的各项研究已取得了丰硕的成果。对近年来该领域研究的最新进展和研究成果进行总结和概括,包括气候统计方法对雾特征的研究、数值模拟方法对雾的机制研究、雾微物理结构研究、雾的监测识别与预报技术研究。在此基础上,针对目前雾研究领域的热点和未来可能的研究方向进行了分析,包括高速公路大雾天气的研究、霾研究、雾与城市化相互作用以及沿海和复杂地形地区雾的研究。     

浙江中部一次大雾过程分析与预报

利用NCEP再分析格点资料、常规观测资料、数值预报产品以及卫星云图对2009年4月6日早晨浙江中部一次大范围大雾天气过程进行诊断分析。结果表明：高空槽后暖脊的大气环流背景有利于地面长波辐射冷却和中层增温,易形成逆温,为大雾生成提供了有利条件,而边界层逆温层或等温层的形成与维持对雾的发展持续具有重要作用;凝结核、低层湍流混合是山区能见度较城镇大的主要原因;交叉温度可用来预示整个潜在雾层的湿度状态,温度与交叉温度差值可作为了解大雾生成、发展、消散过程的一项指标;模式产品能提供雾形成的环境条件;红外云图、可见光云图有助于预测雾的形成、发展、消散过程。     

Macro-and Micro-Structures of Heavy Fogs and Visibility in the Dayaoshan Expressway

Belonging to the southern subtropical moist type of monsoon climate,the Nanling mountainous area experiences heavy fogs whenever quasi-stationary fronts appear there from September to May.There can be as many as 15-18 days of heavy fogs per month.Fogs have more serious consequences in the Lechang-Ruyuan section of the Beijing-Zhuhai Expressway(the longest expressway in China)that passes through the main part of the Nanling Mts.,where the road rises from 200m to more than 800m above sea level(ASL).For a major motorway in the mountainous areas of Nanling Mts.,two multidisciplinary integrated field observations were carried out,which measured visibility by the naked eyes,visibility by instrument,spectrum of fog- drops,liquid water content(LWC)of fog,tethered sounding,dual-parameter low-level sounding,turbulence diffusion within fog layers,aerosol spectra of size and composition,sampled fog water compositions,and sampled rainwater compositions.Typical cases were probed for their analyses of synoptics,micro- and macro-structures and microphysics.It is understood that heavy fogs take place with high frequency in the area and bring about serious consequences.Being typical advection and upslope fogs,they are in essence low-lying clouds appearing at high altitudes,which are closely related with the activity of South China frontal processes,especially the South China quasi-stationary fronts,and reflect on the role of local terrain as well.The heavy fogs are characteristic of long duration,extremely low visibility,well-organized lump- shaped structure,large-size fog-drops,moderate concentration,high LWC,and stronger turbulent diffusion within the fog layers than in fine sky.They differ much from radiation fogs,which are better documented in previous study in China.It is found that fog LWC is in significant anti-correlation with visibility so that large LWC is associated with small visual range.It is also noted that one of the reasons for the fluctuation of characteristic quantities of micro-structure such as the LWC of fog in the area is,in addition to the inhomogeneous structure of the fog itself,the effect of advection and inhomogeneous underlying surface; during the translation of fog with the ambient wind,irregular upslope and cross-over movement is another reason for the inhomogeneous structure and fluctuation of fog.The spectrum of the aerosol size displays itself as the power function of monotonous descent.The concentration of submicrometer particles is even higher.The high-concentration sulfate particles found in the aerosols of Nanling Mts.are actually good nuclei for condensation,which are favorable for the formation of fog.The presence of fog can help cleanse the trace compositions in the atmosphere so that fog droplets contain high levels of polluting elements.In the meantime,compared to cloud droplets,fog droplets are easier to be captured by the vertical surfaces of objects on the land surface,such as vegetation and buildings to constitute another kird of cleansing process. In vast stretches of forest like the Nanling Mts.,this kind of cleansing may be quite important.Studying the characteristic variation of fogs in the area realistically assists in setting up a forecast and warning system for local fogs and provides basic information for fog dispersal experiments.