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1.
河北一次层状云系降水的微物理机制数值模拟与分析 总被引：1，自引：0，他引：1
利用一维层状云模式,详细分析了2009年5月1日中国中东部地区一次层状云系的微物理结构和降水过程。结果表明：此次降水为层状云系降水,云系垂直结构符合顾震潮三层概念模型和“播种云-供给云”机制,其中第一层（上层：4.7-7.0 km）存在冰雪晶,雪主要通过冰晶自动转化和凝华增长。第二层（中层：2.6-4.6 km）有冰晶、雪、霰、云水、雨滴,此层贝吉龙过程作用明显。第三层（下层：1.3-2.5 km）主要粒子为云滴、雨滴、从上层融化的雪和霰,霰的融化对于雨滴的形成贡献最大。云体发展成熟时,各层之间存在一定的播种－供应关系,如第一层向第二层顶部播撒雪和冰晶,第二层向第三层顶部播撒霰和雪。 相似文献
2.
东北冷涡中尺度云系降水机制研究 II: 数值模拟 总被引：1，自引：1，他引：0
在利用卫星、雷达和机载PMS(粒子测量系统)等观测资料对2003年7月8日东北冷涡积层混合云系的降水形成机制分析的基础上,将观测分析与数值模拟研究相结合,用中尺度数值模式对积层混合云系做数值模拟,并结合观测资料进一步分析了积层混合云系的微物理结构、粒子形成过程和降水形成机制,获得如下结果:(1)混合云中对流云具有分层的微物理结构.冰晶含水量最大值出现的高度最高,其次由高到低的排序是雪、云水、霰和雨;雨水主要出现在云的暖区;各种粒子中以雨水含水量最高,其次是霰.对流云体生命期较长,微物理结构基本稳定.(2)粒子形成增长过程有差异.冰晶通过凝华过程增长.雪主要来源于冰晶,产生后主要通过撞冻、收集冰晶和凝华过程增长,其中撞冻过冷云水增长对雪质量贡献最大,其产生率极大值高度与过冷云水相当.丰富的过冷云水,给雪的撞冻增长提供了有利条件.在高、中和低层雪的形成有着不同的机制,高层雪收集冰晶长大后,下落到低层又以雪撞冻过冷云水的结淞增长为主要过程.霰主要由雨滴冻结和雪的转化产生,过冷雨滴与冰晶接触冻结成霰;过冷雨滴收集雪,雪随着雨滴的冻结而转化成霰.因此霰的产生与过冷雨滴关系极大.霰主要撞冻云水、收集雪和冰晶增长,其中撞冻是霰的重要增长过程.雨水主要由霰的融化形成,降水主要是由冷云过程产生的.在过冷层,霰撞冻增长占优势.云上部的冰晶和雪对云的中部具有播撒作用,过冷层中存在丰富的过冷水,对冰相粒子的撞冻增长有利.对云水消耗的分析表明,雨滴对云滴的收集、霰和雪对云水的撞冻增长是消耗云水的主要过程.(3)从各种粒子的形成和增长过程可以看出,大部分雨水由霰融化形成,暖云过程贡献要小得多.可见,降水主要是由冷云过程产生的,这与观测分析的结果一致. 相似文献
3.
采用中国气象科学研究院 (CAMS) 中尺度云参数化模式对2010年4月20日山西省一次春季层状降水云系的宏微观结构,特别是垂直方向上的微物理结构进行了数值模拟和分析。利用携带云粒子探测设备的飞机对该次层状云系进行了两次云物理探测飞行,并将飞机探测所获取的数据和图像资料与数值模拟结果进行了对比研究。模拟结果显示:该次降水过程以层状冷云降水为主,云中过冷水含量丰富,云系存在明显的3层结构,地面降水主要来自于云中高层冰晶、雪、霰等冰相粒子的融化和低层云水的转化。数值模拟与飞机探测对比分析显示,高空温度、湿度和高度的配置两者基本一致,数值模拟不同高度的云粒子相态、垂直方向云水比含水量与飞机探测获取的云粒子图像和云液态水含量的垂直结构基本吻合,但数值模拟的云中各种水成物粒子出现的高度较飞机探测偏高。 相似文献
4.
应用数值模式结果,选择台风登陆后两个不同时次螺旋雨带中两个强降水中心,对台风螺旋雨带的云结构和降水形成机制进行诊断分析.结果发现螺旋雨带云结构和降水形成机制有如下特点:在9～13 km高空范围内冰晶的非均质核化非常活跃,冰晶转化率高于台风眼壁暴雨数倍,但是冰晶通过贝吉龙过程生长为雪、雪通过凝华增长生长为霰的过程相对台风眼壁很弱,螺旋雨带雨水形成微物理机制以霰粒子融化成雨水(pgmlt)为主,冰相粒子转化率大值区位于垂直上升气流大值区,8 km高度霰收集雪(dgacs)干增长是最主要的冰相粒子生长过程,与北方层状云比较,螺旋雨带暴雨冷云中的凝华过程和撞冻过程非常活跃.螺旋雨带云水凝结过程呈双峰型,位于7～8 km高度冷云区的云水凝结峰值较大,暖云区0.5～1.5 km高度云水凝结峰值次之. 相似文献
5.
杨俊梅 《沙漠与绿洲气象(新疆气象)》2023,17(6)
基于2011年5月9日山西中部地区一次积层混合云降水的机载探测和地面雨滴谱观测资料,分析了空中云系微物理参量的垂直分布、冰晶形态及演变和地面降水的微物理特征。结果表明：此次积层混合云为冷云结构,垂直分布不均匀,云中过冷水较为丰沛,对流泡的存在造成云内不同区域云水含量不均匀。云滴的凝华增长导致5.3 km处大云粒子和降水粒子数浓度明显增加。小云粒子谱分布以单峰型为主,峰值直径主要位于5～6 μm或9～10 μm,大云粒子谱分布呈多峰型,不同高度处变化较大。此次降水观测到的冰晶形态包括板状、针柱状、柱帽状、辐枝状和不规则形状,4.9 km处受聚合和淞附过程的共同影响,辐枝状和针柱状冰晶增多,在4.1 km处融化层附近淞附状冰晶明显增加。地面降水受到雨滴谱仪布设位置的影响,其微物理结构主要呈现为层状云降水的特征。 相似文献
6.
积-层混合云是影响北京地区的重要降水云系,运用飞机探测资料结合中尺度数值模式WRF,对2014年9月23日发生在北京地区的一次积-层混合云系的垂直结构和降水机制进行了探测资料分析和数值模拟研究。通过分析云系的雷达回波演变,发现云中的对流泡没有出现爆发式增长,回波在垂直方向上增长不明显,此次过程属于积-层水平混合型云系降水。飞机探测资料分析显示,上、下午探测云系的液态水含量都不高（最大低于1 g/m3）;在云系不同高度,飞机探测到的冰晶形状主要有板状、针柱状、辐枝状和不规则状,由于云中过冷水含量相对较低,聚合冰晶的数量明显多于凇附冰晶,冰晶的聚合是云中粒子增长的主要过程。对模拟云系垂直微物理结构和降水粒子的源、汇项分析得到:高层,由凝华产生的冰晶和雪晶在过冷水含量较低的环境中不断聚并、长大并下落,云系中霰的含量很低,增大的冰晶和雪晶下落至0℃层附近融化是产生地面降水的主要机制。此外,融化层附近,雨滴捕获云滴不断长大并下降至地面也是地面降水的另一个重要来源。 相似文献
7.
利用机载微物理探测仪器获得了2010年4月20～21日我国中东部地区的一次大范围降雨过程的观测资料,详细分析了云系的微物理结构和降水过程,并利用WRF模式对降水过程进行了数值模拟分析,详细探讨了此次降雨形成的微物理机制。分析表明,降水前期,云体在垂直方向上存在分层结构,云粒子探头(Cloud Droplet Probe, CDP)粒子浓度存在较大起伏。降水中期,CDP粒子主要存在于4.27 km以下,其中3.69 km处浓度较大,峰值普遍超过100 cm-3;降水粒子和尺度较大的云粒子同样在4.27 km以下。4.27 km、3.69 km处粒子形态较丰 富,经历了不同尺度的片状、不规则状、针状及辐枝状的变化,3.69 km处CDP粒子浓度较少时,降水粒子以针状为主,而CDP粒子浓度充足时则转化为尺寸更大的辐枝状粒子。4.27 km、3.69 km高度层存在的主要粒子是雪晶,其次是少许冰晶。降水后期,云体从顶部开始趋于消散,表现为3.9 km高度以上无明显CDP粒子,仅存在部分云粒子和降水粒子,其形态为不规则状。降水主要形成于3.9 km以下的云层,此时冷层仍存在部分针状的冰雪晶。WRF模拟结果表明:雨滴大部分形成于2.9 km以下,0 ℃层下方,2.2～2.9 km雪的融化贡献最大,2.2 km以下重力碰并为主。雪是冷暖层主要的降水粒子,雪在冰雪晶层大部分高度仍以凝华增长为主,混合层以凝华增长和结淞增长为主,而雪的增长程度可能受上升气流强度、过冷水含量影响。 相似文献
8.
一次冷涡过程降水的微物理机制分析 总被引：6，自引：0，他引：6
该文分析了一次冷涡天气过程中云微物理量的分布特征、降水粒子的增长机制及云下雨滴的蒸发效应。主要结果为:云系由低层暖性Sc云和冷性主体As云组成。As云底高2 km,云顶高大于5 km,云中存在比较大的过冷水区,–11.2 ℃时的过冷水含量0.21 g·m-3,但过冷水的含量分布极不均匀,大于0.05 g·m-3的过冷水区连续分布的宽度87%小于2.4 km,不利于云中冰晶的连续凇附增长;同时云下雨滴的蒸发效应大,直径小于1.0 mm的雨滴难以落到地面,因此本次过程只产生弱的降水。 相似文献
9.
甘肃省夏季层状云微物理特征个例分析 总被引：4，自引：2，他引：2
对2004年6月12日甘肃河西地区一次降水性层状云的云物理飞机探测结果进行了分析,通过对云中粒子的浓度、直径、二维图像以及谱型变化地研究,并结合宏观观测记录,详细分析了云系的垂直和水平微物理特征.观测资料分析表明:此次云系为Ac-Sc结构,上层Ac云为纯冷云,下层Sc云为纯暖云,两层云之间存在较厚的干层.云中微物理量的垂直和水平变化均具有明显的不均匀性,整个探测过程中,FSSP-100所测云粒子的浓度和平均直径变化范围分别为0.1～-232.6cm-3和3.5～45.5μm,OAP-2D-GA2所测云粒子浓度及平均直径变化范围分别为0.01～116.7cm-3和32.2～995.7μm.粒子二维图像表明,上层高积云中冰相粒子的凇附、粘连现象普遍,说明云中存在较多的过冷水.图像及谱型分析表明,6000m以上某些区域有冰晶高浓度区存在,大量冰晶的成长消耗了云中过冷水,不利于大云粒子的形成和成长;这次降水雨滴主要由纯暖性Sc云中暖云成雨过程形成,冷云过程只在Sc云顶附近有一定作用,本次降水主要机制为下层层积云中的暖云过程. 相似文献
10.
利用机载Ka波段云雷达（Airborne Ka-Band Precipitation Cloud Radar, KPR）和粒子测量系统（Droplet Measurement Technologies, DMT）,分析了2018年4月22日黄淮气旋背景系统下积层混合云中对流泡的动力和微物理特征。首先,对Ka波段云雷达观测的山东地区春季36个对流泡样本按照回波强度、水平尺度、回波顶高三个参量进行统计,结果表明平均回波强度为20～30 dBZ的对流泡占69%。对流泡水平尺度为15～30 km,占61%。对流泡最大回波顶高集中在6～8 km,比周边层云高2～4 km。之后,对4月22日积层混合云中的对流泡个例微物理参数进行统计,结果表明对流泡内部以上升气流为主,最大上升气流速度达到1.35 m s?1,平均上升气流速度为0.22 m s?1;对流泡内过冷水含量比较高,最大含水量为0.34 g m?3,平均含水量为0.15 g m?3。对流泡内冰晶数浓度是泡外的5.5倍,平均直径是泡外的1.7倍。结合云粒子图像探头,发现对流泡前沿和尾部冰粒子以柱状和辐枝状为主,而对流泡核心区域冰粒子以聚合体形式存在。冰粒子通过凇附过程和碰并过程增长,过冷水含量不足时冰粒子的凇附增长形成柱状粒子,含量充足时可迅速凇附成霰粒子。对流泡内降水形成的微物理机制不完全相同,主要依赖过冷水含量。当云中有充足的过冷水分布时,高层冰晶通过凇附增长形成霰粒子,通过融化层后形成降水;当云中缺少过冷水时,降水的形成主要通过水汽凝华过程形成冰雪晶,然后雪晶通过聚合过程实现增长。 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.
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
13.
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
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.
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
16.
《大气和海洋科学快报》2014,7(6):F0003-F0003
AIMS AND SCOPE
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
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《大气和海洋科学快报》2014,(5):F0003-F0003
AIMS AND SCOPE Atmospheric and Oceanic Science Letters （AOSL） pub- lishes short research letters on all disciplines of the atmos- phere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
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19.
《大气科学进展》2014,(6)
正Aims Scope Advances in Atmospheric Sciences(AAS)is an international journal on the dynamics,physics,and chemistry of the atmosphere and ocean with papers across the full range of the atmospheric sciences,co-published bimonthly by Science Press and Springer.The journal includes Articles,Note and Correspondence,and Letters.Contributions from all over the world are welcome. 相似文献
20.
DING Yihui WU Guoxiong Da-Lin ZHANG ZHANG Renhe Co-Chief Editors 《Acta Meteorologica Sinica》2014,28(5):669-670
As we will soon celebrate the 90th anniversary of the founding of the Chinese Meteorological Society （CMS）,Acta Meteorologica Sinica （AMS）,which was originally named as Bulletin of the Chinese Meteorological Society,has gone through 89 years of development and excitement since her first issue in July 1925.According to archived documents （CMS Editorial Committee,1925）,AMS was founded to report the research findings of Chinese meteorologists,record their recommendations for improving meteorological services,and share their common meteorological interests in order to promote the growth of AMS such that more members could be inspired to conduct atmospheric research and meteorological knowledge would be better disseminated to and benefit the general public.By upholding and carrying forward this purpose,AMS has published many highly valuable scientific papers.Some could be treated as classical articles,which have produced important influences on both domestic and international meteorological communities and the related fields. 相似文献