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1.
多普勒天气雷达资料对中尺度模式短时预报的影响 总被引：22，自引：8，他引：22
利用中尺度模式ARPS(The Advanced Regional Prediction System)及其资料分析系统ADAS(ARPS Data Analysis System),将国内新一代多普勒雷达(CINRAD)反射率及径向风资料直接用于中尺度数值模拟,通过一次华北地区暴雨过程的模拟对比试验,分析了雷达资料对初始场的改进效果及其对模拟结果的影响,结果表明:(1)利用雷达径向风资料对初始风场进行调整后,自近地面到对流层顶的u,v,w都发生了变化,调整后的初始风场在对流层中层变化最大.(2)利用雷达反射率进行微物理调整和云分析能调整初始场中的云水信息,使得雷达回波附近3 km以下的水汽混合比(qv)增加,4 km以下的雨水混合比(qr)增加,对流层(约10 km以下)的云水混合比(qc)增加,4～9 km的对流层上部云冰混合比(qi)和雪混合比(qs)增加.ADAS通过非绝热初始化调整温度场,从而得到了一个动力和热力上平衡的初始场.(3)模拟的1 h雨量与实况的对比表明,同时利用雷达反射率和径向风改进过的初始场能明显增强3 h内的降水强度和落区预报,改善中尺度数值模式短时定量降水预报.模拟的1 h流场对比分析表明,经雷达径向风调整后,能够在初始场中增加气旋性涡旋等中小尺度风信息,明显减少模式的spin-up时间.(4)通过对雷达径向风和反射率对模式初始场和模拟结果影响的对比分析发现,雷达径向风主要是改进初始风场,而雷达反射率主要是改进初始场中的湿度参数,增加初始场中云水等的含量,调整温度场.通过模拟的6 h降水对比发现,利用雷达径向风调整初始场后,对降水模拟有一定的改进,但效果不甚明显,而雷达反射率资料对定量降水预报改进效果明显,同时使用雷达径向风和反射率资料改进初始场后对降水的模拟效果最明显. 相似文献
2.
一次大暴雨过程的多普勒雷达资料同化的敏感性试验 总被引：3，自引：1，他引：2
利用WRF中尺度模式及WRF-3DVAR变分同化系统和LAPS雷达资料前处理模块建立试验平台,直接同化S波段多普勒雷达反射率和径向速度资料,通过对2008年8月15-16日发生在我国长江中游的一次大暴雨过程的各项预报对比试验研究,初步检验和评估不同种类多普勒雷达观测数据同化对改进数值模式初始场及其数值预报能力的影响及作用.初步结果表明:多普勒雷达资料同化对提高暴雨数值预报能力有重要作用.无论在24 h累计降水还是在逐时降水预报方面,同化多普勒雷达资料均可使降水雨带分布和强降水中心预报的准确性得到较大改善;多普勒雷达反射率资料同化对初始水汽场的改变显著,对初始风场影响较小,而同化径向速度对初始水汽场的改变较小,但可增加初始风场的中小尺度信息,使初始风场产生较大变化.总体上看,虽然雷达反射率和径向速度资料同化均可改进强暴雨的数值预报,但雷达反射率资料同化对降水雨带和中心预报的改进更为显著和重要. 相似文献
3.
利用ARPS模式(Advanced Regional Prediction System)的资料分析系统ADAS(ARPS Data Analysis Sys-tem),以NCEP GFS资料为背景场对我国西北地区CINRAD-CB\CC型雷达反射率资料进行同化试验研究,并借助于WRF(Weather Research and Forecasting Model)模式,对发生在黄河河套及河北地区的一次天气过程进行个例模拟试验。不同模拟方案模拟结果的对比分析和短时预报检验表明:①C波段雷达反射率资料的引入与S波段雷达反射率资料在空间覆盖上构成互补,与卫星、地面等资料的云综合分析能够分析出与实况更为接近的降水场和垂直结构信息;②同化了C波段雷达反射率资料的试验方案在模拟回波系统演变上优于未同化的,但由于模拟低层暖湿条件不足,系统逐渐衰弱与实况不符;③对比实况降水发现,区域C波段雷达反射率资料的同化对短时降水预报效果有一定改善。 相似文献
4.
利用美国CAPS的非静力高分辨率区域预报模式ARPS(先进区域预报系统)对0414号台风"云娜"进行数值模拟,模拟结果表明ARPS较好地模拟台风"云娜"的移动路径及台风大暴雨.并着重讨论新一代天气雷达资料对台风"云娜"数值模拟的影响,通过对雷达资料同化进模式与没有雷达资料同化进模式对比模拟的试验结果分析表明:雷达资料进模式,对中高层的风场调整,改进对台风细微结构特征描述,加大近台风中心南侧的西风分量和近台风中心西侧的北风分量,从而改进云娜台风登陆后西行移动路径预报;对扰动温度、雨水混合率、云水混合率及水汽混合率场等调整,改善模式初始场台风中高层成雨条件,对台风降水预报,尤其暴雨的落区、降水分布及其随时间变化的预报有较大改进. 相似文献
5.
利用美国CAPS的非静力高分辨率区域预报模式ARPS（先进区域预报系统）对0414号台风“云娜”进行数值模拟，模拟结果表明ARPS较好地模拟台风“云娜”的移动路径及台风大暴雨。并着重讨论新—代天气雷达资料对台风“云娜”数值模拟的影响，通过对雷达资料同化进模式与没有雷达资料同化进模式对比模拟的试验结果分析表明：雷达资料进模式，对中高层的风场调整，改进对台风细微结构特征描述，加大近台风中心南侧的西风分量和近台风中心西侧的北风分量，从而改进云娜台风登陆后西行移动路径预报；对扰动温度、雨水混合率、云水混合率及水汽混合率场等调整，改善模式初始场台风中高层成雨条件，对台风降水预报，尤其暴雨的落区、降水分布及其随时间变化的预报有较大改进。 相似文献
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7.
《气象》2021,(8)
为了更好地应用闪电观测资料,在华中区域快速更新循环同化系统中引入适用于本地的闪电定位资料与代理回波特征的转换关系,并开展了相应的同化应用研究。针对2015年6月1日发生在湖北监利的一次强降水过程,开展了利用新、旧闪电-代理回波的对比同化试验,重点分析了引入新的闪电-代理回波转换关系对模式计算的雷达反射率、云微物理变量和降水预报的影响,并与直接同化雷达反射率进行对比。数值试验结果表明:新的闪电-代理回波关系较好地捕捉到强降水信号,通过调整初始时刻云水、雨水、云冰、云雪、霰等微物理量,尤其是提高了初始时刻雨水、云水的含量,达到调整降水预报的目的;对比降水结果可以得到在使用新的闪电-雷达回波关系后,能够有效降低漏报率,并且模式在短时间尺度可以响应出与实况更为接近的降水预报,提高短时临近预报准确率,取得了与直接同化雷达反射率相似的结果。 相似文献
8.
运用物理初值化方法,将气象卫星资料引入模式初始场,使初始场向观测场逼近,试图改进由于初始资料不完善而造成的模式积分前期降水量偏少的现象。应用ARPS中尺度模式对天津地区的一次强降水天气过程进行了数值模拟对比试验,结果表明,加入卫星观测资料后,部分卫星观测为对流云区,水汽和云水物质的水平和垂直分布进行了较为明显的调整,模式的临近短时降水预报也有明显增强的趋势。可判断出模式的初始状况更接近观测实际,对提高中小尺度天气系统的短期和临近预报的准确率有积极作用。 相似文献
9.
为了改善低纬高原地区天气预报水平,利用WRF(Weather Research and Forecasting)模式及其变分同化系统进行雷达VAD(Velocity Azimuth Display)反演风场资料同化试验。通过设计不同的试验方案,对2009年6月30日00:00至7月1日00:00发生在云南的一次强降水过程进行数值模拟和对比分析,结果表明:同化VAD反演风场资料后对区域模式的风矢量初始场有明显影响。同化系统能把雷达反演风场信息有效地引入模式初始场,改善强降水区域的水汽输送和风场辐合强度;同化VAD反演风场资料后对区域模式累计降水预报有一定改进作用。从长时间累计降水量定量检验结果看,具体表现为25mm以上量级的降水准确率明显提高、漏报率下降,预报偏差更趋合理。不同的同化试验方案之间的模拟结果差异较大。同化频率越高、同化持续时间越长,对区域模式初始场和预报场的影响越明显。但同化持续时间不宜过长,否则可能导致系统移速过快、降水强度偏大、空报率增加等异常。 相似文献
10.
高分辨率的中尺度预报模式ARPS及其3DVAR/云分析系统,针对2010年登陆福建的超强台风“鲇鱼”,研究对流可分辨尺度下,每1h循环同化沿海新一代多普勒雷达网资料分析、研究对台风初始场和预报场的改进作用.结果表明:单独同化雷达资料可显著改善初始场中的台风内核区动力和热力结构,以及台风强度和位置,进而提高18h台风强度、路径和降水预报,但预报路径和降水分布与实况仍存在差异.在雷达资料同化基础上加入常规观测资料,对初始场中台风内核区结构改进不大.但在显著调整大尺度背景场,从而进一步减少台风路径预报误差,能准确预报出福建沿海两个强降水区域的位置和强度.总体而言,雷达资料同化主要提高台风结构分析,而常规观测资料同化主要改善环境场分析,两者有效结合使得预报结果和实况最为接近. 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.
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
13.
《大气和海洋科学快报》2013,(4):227
正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. 相似文献
14.
Connections between the Eurasian teleconnection and concurrent variation of upper-level jets over East Asia 总被引：3，自引：0，他引：3
The variation of the East Asian jet stream(EAJS) associated with the Eurasian(EU) teleconnection pattern is investigated using 60-yr NCEP–NCAR daily reanalysis data over the period 1951–2010. The EAJS consists of three components: the polar front jet(PFJ); the plateau subtropical jet(PSJ); and the ocean subtropical jet(OSJ). Of these three jets over East Asia,the EU pattern exhibits a significant influence on the PFJ and OSJ. There is a simultaneous negative correlation between the EU pattern and the PFJ. A significant positive correlation is found between the EU pattern and the OSJ when the EU pattern leads the OSJ by about 5 days. There is no obvious correlation between the EU pattern and the PSJ. The positive EU phase is accompanied by a weakened and poleward-shifted PFJ, which coincides with an intensified OSJ. A possible mechanism for the variation of the EAJS during different EU phases is explored via analyzing the effects of 10-day high-and low-frequency eddy forcing. The zonal wind tendency due to high-frequency eddy forcing contributes to the simultaneous negative correlation between the EU pattern and the PFJ, as well as the northward/southward shift of the PFJ. High- and low-frequency eddy forcing are both responsible for the positive correlation between the EU pattern and the OSJ, but only high-frequency eddy forcing contributes to the lagged variation of the OSJ relative to the EU pattern. The negative correlation between the EU pattern and winter temperature and precipitation anomalies in China is maintained only when the PFJ and OSJ are out of phase with each other. Thus, the EAJS plays an important role in transmitting the EU signal to winter temperature and precipitation anomalies in China. 相似文献
15.
<p>PARTITION OF SEASON BASED ON MULTIELEMENTS AND THE DECADAL CHANGE OF SEASON DURATION IN CHINA</p>
<p>Using the multielements similarity measurement method and 1950–C2017 NCEP/NCAR gridded daily reanalysis datasets, we analyzed season duration in China during 1950–C2016, and we defined the element with maximum absolute sensitivity as the key impact element at each point using the sensitivity analysis method. The decadal change of season duration and its key impact element before and after 1980 were studied. The results indicated obvious meridional and zonal differences in the distribution of season duration for the 67-year average, and that the key impact element has the same distribution characteristics as season duration. In addition, complementary relationships were found between the durations of spring and summer, autumn and winter, and the cold and warm seasons. Of those, the complementary relationship between the durations of spring and summer was strongest and the regions of complementarity were numerous. The complementary regions of autumn and winter durations were found mainly in western China. In the cold and warm seasons, the complementary regions were widespread and the complementary relationship was generally weak. Comparison of the periods before and after 1980 revealed an east–Cwest difference in the interdecadal variation of season duration. Interdecadal variation in spring and summer was found concentrated in northern and western regions, while that in autumn and winter was concentrated in the western region. Areas of significant interdecadal variation of the key elements were found concentrated in northern and western regions, corresponding well with the areas of significant interdecadal variation of season duration.</p> 相似文献
16.
By using the gauged rainfall in 160 stations within mainland China and the NCEP/NCAR reanalysis data, the impacts of anomalous SST in Kuroshio and its extension on precipitation in Northeast China were investigated. The results show that a difference in the meridional circulation such as the East Asia/Pacific teleconnection pattern(EAP)may be responsible for the difference in rainfall between 1998 and 2010. In comparison with 1998, the anomalous meridional circulation pattern in 2010 shifted northeastward, and then the western subtropical high, the mid-latitudinal trough and the northeastern Asia blocking high also shifted northeastward, causing intensified convergence of the cold and warm air masses at the southern region and thus more rainfall in the southwestern region and less in the northwestern region. In 1998, the anomalous cyclone, one component of the meridional pattern, located at the Songhuajiang-Nengjiang River basin, resulted in more rainfall in the majority of the area. The results of observation and the model show that the difference in SSTA in Kuroshio and its extension under the background of different El Ni觡o events is the key point:(1) The anomalous warmth moved westward from the mid-Pacific to the east of the Philippine Sea during the central event, which led the heat resources shifting to the northeast in 2010; subsequently, a shift occurred to the north of the anomalous ascent and decent, followed by a warm SSTA in the region of Kuroshio's extension in 2010 and Kuroshio in 1998.(2) The warm SSTA in the Kuroshio extension causing the Rossby wave activity flux strengthened in 2010, and then the westerly jet shifted northward and extended eastward. A warm SSTA in Kuroshio and cold SSTA in its extension in 1998 caused the westerly jet to shift southward and weaken. As a result,the anomalous anticyclone and cyclone shifted northward in 2010, and the blocking high also shifted northward. 相似文献
17.
Understanding potential future influence of environmental, economic, and social drivers on land-use and sustainability is critical for guiding strategic decisions that can help nations adapt to change, anticipate opportunities, and cope with surprises. Using the Land-Use Trade-Offs (LUTO) model, we undertook a comprehensive, detailed, integrated, and quantitative scenario analysis of land-use and sustainability for Australia’s agricultural land from 2013–2050, under interacting global change and domestic policies, and considering key uncertainties. We assessed land use competition between multiple land-uses and assessed the sustainability of economic returns and ecosystem services at high spatial (1.1 km grid cells) and temporal (annual) resolution. We found substantial potential for land-use transition from agriculture to carbon plantings, environmental plantings, and biofuels cropping under certain scenarios, with impacts on the sustainability of economic returns and ecosystem services including food/fibre production, emissions abatement, water resource use, biodiversity services, and energy production. However, the type, magnitude, timing, and location of land-use responses and their impacts were highly dependent on scenario parameter assumptions including global outlook and emissions abatement effort, domestic land-use policy settings, land-use change adoption behaviour, productivity growth, and capacity constraints. With strong global abatement incentives complemented by biodiversity-focussed domestic land-use policy, land-use responses can substantially increase and diversify economic returns to land and produce a much wider range of ecosystem services such as emissions abatement, biodiversity, and energy, without major impacts on agricultural production. However, better governance is needed for managing potentially significant water resource impacts. The results have wide-ranging implications for land-use and sustainability policy and governance at global and domestic scales and can inform strategic thinking and decision-making about land-use and sustainability in Australia. A comprehensive and freely available 26 GB data pack (http://doi.org/10.4225/08/5604A2E8A00CC) provides a unique resource for further research. As similarly nuanced transformational change is also possible elsewhere, our template for comprehensive, integrated, quantitative, and high resolution scenario analysis can support other nations in strategic thinking and decision-making to prepare for an uncertain future. 相似文献
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Characterization and source apportionment of volatile organic compounds in urban and suburban Tianjin,China 总被引：1，自引：0，他引：1
Tianjin is the third largest megacity and the fastest growth area in China, and consequently faces the problems of surface ozone and haze episodes. This study measures and characterizes volatile organic compounds(VOCs), which are ozone precursors, to identify their possible sources and evaluate their contribution to ozone formation in urban and suburban Tianjin,China during the Ha Chi(Haze in China) summer campaign in 2009. A total of 107 species of ambient VOCs were detected,and the average concentrations of VOCs at urban and suburban sites were 92 and 174 ppbv, respectively. Of those, 51 species of VOCs were extracted to analyze the possible VOC sources using positive matrix factorization. The identified sources of VOCs were significantly related to vehicular activities, which specifically contributed 60% to urban and 42% to suburban VOCs loadings in Tianjin. Industrial emission was the second most prominent source of ambient VOCs in both urban and suburban areas, although the contribution of industry in the suburban area(36%) was much higher than that at the urban area(16%). We conclude that controlling vehicle emissions should be a top priority for VOC reduction, and that fast industrialization and urbanization causes air pollution to be more complex due to the combined emission of VOCs from industry and daily life, especially in suburban areas. 相似文献
20.
气候变化对中国东部季风区水资源脆弱性的影响评价 总被引：3，自引：0，他引：3
将耦合暴露度、灾害风险、敏感性与抗压性的脆弱性评估模型应用于中国东部季风区水资源脆弱性评价,从水资源供需平衡角度分析了气候变化对东部季风区水资源脆弱性的影响。结果表明,2000年气候条件下,我国东部季风区接近90%的区域水资源处于中度脆弱及以上状态。其中水资源中度和高度脆弱区域约占全区的75%,极端脆弱区域接近15%。中国北方海河、黄河、淮河和辽河流域的水资源脆弱性最高。未来气候变化影响将加剧水资源脆弱性的风险,不同RCP排放情景下2030年代我国东部季风区水资源中度脆弱及以上区域面积有明显的扩大,极端脆弱区域将达到20%~25%。由于未来需水的进一步增加,中国北方水资源脆弱性的格局并未发生根本变化,而南方东南诸河等区域将面临可能发生的水危机。 相似文献