基于DVB-S数据共享平台的NOAA/ATOVS资料获取、处理与显示系统

充分利用国家科技部大力推行的DVB-S共享数据平台, 加强气象卫星遥感数据的广泛应用, 特别是发挥卫星垂直探测器 (ATOVS) 资料在我国数值天气预报以及监测重大灾害性天气系统中的作用。该文介绍了基于DVB-S系统的NOAA/ATOVS资料的处理、分析与显示系统的概况及主要功能, 并以2005年7月人们关注的台风“海棠”为个例, 展示了利用该系统在监测和分析台风或强对流天气时的独特优势。该系统的建立, 将解决省、地气象部门不能实时获取ATOVS资料的问题, 并将推动ATOVS资料在气象以及相关部门的实际应用。     

新型台风海洋网络气象信息系统的设计与实现

该文将时空数据模型的概念引入台风海洋网络气象信息系统,旨在构建一个多源、异构气象服务产品与数据按照统一的时空数据模型进行组织、集成和融合,并在互联网上实时展现的信息系统平台。介绍了该系统的设计思路和技术框架,同时分析了该系统中引入时空数据模型的技术难点和关键技术,重点展示了系统构建成型后能实现的主要功能,包括台风路径信息与卫星云图、天气形势场等多种气象信息的叠加显示;多功能历史台风路径信息查询;台风实况路径信息与城市风雨监测实况、卫星云图、雷达图的同步动画显示;气象灾害预警信息、气象资讯、城市天气实况及预报等内容的集成发布等。该研究成果已在中国天气台风网（typhoon.weather.com.cn）得到实际应用。     

ATOVS 不同卫星资料在台风模拟中的同化试验研究

利用美国国家大气研究中心(NCAR)开发的中尺度模式WRF(ARW)V3.2 及其三维变分同化系统WRF-3DVAR,以1011 号超强台风“ 凡亚比” 为个例,采用连续循环同化的方法对ATOVS 卫星资料进行同化试验,探讨了同化ATOVS 不同卫星资料对“ 凡亚比” 模拟的影响。结果表明,强度影响方面:同化ATOVS不同资料均可有效改善台风强度,台风中心海平面气压平均偏差从42 hPa 下降到18 hPa,但不同资料间的差异并不显著,平均在6 hPa 以内,这表明仅同化ATOVS 资料对台风强度的改善相对有限。路径影响方面:(1)不同卫星的同一种传感器资料效果略有不同,同化NOAA-18 和NOAA-15 的AMSU-A 资料效果较好,NOAA-16 的AMSU-A 效果较差;同化NOAA-15 和NOAA-16 的AMSU-B 资料效果相当,且均优于AMSU-A 资料。(2) 同一颗卫星不同传感器资料的差异较大,同化AMSU-B 资料的改善较为明显,HIRS-3 次之,AMSU-A较差,而同时同化不同资料并没有带来更为明显的改善。(3) 同时同化多颗卫星ATOVS 资料的试验表明,将多种资料引入到同化系统的同时,也带来相应的累积误差,因而仅同化一颗卫星可能比同时同化两颗或三颗卫星ATOVS 资料的效果要好。      

中国气象局卫星广播系统 (CMACast) 设计

CMACast是中国气象局基于DVB-S2标准的新一代卫星数据广播系统,使用亚洲卫星4号星一个完整的C波段转发器对中国及亚太地区进行气象资料、卫星遥感资料及流媒体视频的广播。该文详细介绍了CMACast的系统结构、主要功能和关键技术,并与中国气象局现有的3个广播系统PCVSAT,DVB-S和FENGYUNCast以及EUMETCast,GEONETCastAmericas进行了比较。比较结果表明:CMACast覆盖面广,技术领先,功能强大,是目前世界领先的卫星数字广播系统。预计2012年初CMACast全面建成并投入使用,CMACast系统建成后,将全面整合PCVSAT,DVB-S和FENGYUNCast 3个系统的业务和用户,成为中国气象局唯一的广播系统,并作为GEONETCast的亚洲区域中心,向亚太地区进行GEOSS数据的广播。     

ATOVS微波观测对2008年台风预报影响的初步评估

为了评估同化ATOVS卫星微波资料在台风数值预报中的影响,利用中尺度模式WRF和三维变分同化系统WRFDA,采用国家卫星气象中心接收处理的卫星微波温度计AMSU-A辐射率L1c数据集,针对在2008年台风季中影响我国大陆的8个台风典型,开展批量卫星资料同化和数值预报试验。对同化效果的检验和对同化前、后西太平洋副热带高压的分析表明:AMSU-A资料对台风预报有改进作用,在44%的48 h预报样本中同化后路径有改善;同化微波资料后,副热带高压的改变直接影响台风路径。      

DVB-S在气象数据广播中的应用研究

DVB-S卫星数据广播系统技术成熟、开放性好、硬件成本低、传输速率高,能很好地承担各种气象数据业务和视、音频广播业务。该文介绍DVB-S数据广播系统的基本组成,并结合新一代卫星通信气象数据广播系统的总体需求、总体技术设计、试验系统建设,对主站和小站的业务应用方式进行研究。基于DVB-S的新一代气象信息卫星广播系统建设,将大大提升国家气象信息中心气象信息广播分发和服务能力。大力开展围绕采用DVB-S技术的气象业务应用研究,拓展和衍生各种应用服务领域,是目前所面临的重要任务。     

自动气象站和人工气象站气温差异特征分析

2006年5月27日,全国第一个新一代气象数据卫星接收站在山西省气象信息中心投入业务试运行,该系统采用的是D V B传输协议。DVB-S(Digital Video Broadcastby Satellite)气象数据接收站在山西省的成功安装,标志着我国新一代气象数据卫星广播系统建设工作拉开了序幕。该系统的业务化运行将大大增加气象信息的数据量,提供高质量的流媒体广播,为提高天气预报准确率和气象服务时效奠定坚实的基础。目前新系统运行一切正常。     

极轨气象卫星数据Web共享平台的建设

基于国家科技部大力推行的DVB-S系统,依托AutoI、tSQLite、Prototype等开源软件构建了极轨气象卫星W eb共享平台,探讨了其方案设计和技术实现。该平台实现了极轨卫星数据实时处理、自动发布、W eb交互展示和数据共享等功能,有效地拓展了DVB-S数据接收系统的使用价值,为卫星数据的后续开发、成果交流及气象应用创造了有利条件。     

雷电监测数据分析系统的开发及应用

雷电监测资料的分析处理是研究强对流天气过程中的雷电活动特征和建立雷电预警预报新方法的基础.文中论述了雷电监测数据分析系统CAMS_LDAS)的可视化设计原理、思想和方法,并以2005年8月12日北京地区雷电监测资料的分析为例,详细阐述了该系统的主要功能以及产品.该系统不仅能够对雷电监测数据进行处理和分析,还能综合显示分析雷达回波和卫星云图等多种气象探测资料,是研究雷电活动特征及其与各种气象参量相互关系的有力工具.     

利用ATOVS反演产品分析“云娜”台风

ATOVS能接收到穿透台风中心密实云区的微波辐射信息, 利用ATOVS大气参数反演产品分析0414号台风“云娜”的热力结构特征。在准静力平衡假设的前提下, 根据ATOVS对“云娜”台风监测相匹配的4个时次数据, 分别计算出相应的中心海平面最低气压, 同中央气象台利用可见光和红外技术得到的台风报告值相比, 平均偏差为11.8 hPa, 它随时间的变化能显示台风强度演变的过程。     

ATOVS资料同化方案对暴雨模拟效果的影响

本文利用WRF 模式及其3DVar 同化系统,以2009 年6 月29 日00 时到30 日00 时的湖北鹤峰暴雨为研究个例,对ATOVS 探测器的AMSU-A、AMSU-B 和HIRS 三类资料进行了不同的同化方案试验。结果表明:同化ATOVS 三类资料对暴雨模拟的影响不同,HIRS 资料对暴雨模拟效果改进最大,AMSU-B 次之,AMSU-A 最小。同时同化ATOVS 三类资料时,AMSU-A 资料起主要作用,其同化效果与同时同化ATOVS 三类资料相近,优化组合同化AMSU-B 和HIRS 资料的效果最好。同化ATOVS 不同资料对初始要素场的影响不同,AMSU-A 资料主要影响大气温度场,AMSU-B 资料对中高空要素场的影响较大,HIRS 资料对低空湿度场及风场的协同改变最有利于降水模拟的改善。同时ATOVS 资料的稀疏分辨率也是影响同化效果的一个因子,在模式分辨率不变时,同化资料稀疏分辨率可能存在最佳选择。     

A STUDY ON SATELLITE DATA ASSIMILATION WITH DIFFERENT ATOVS IN TYPHOON NUMERICAL EXPERIMENTS

Based on the newly developed Weather Research and Forecasting model(WRF)and its three-dimensional variational data assimilation(3DVAR)system,this study constructed twelve experiments to explore the impact of direct assimilation of different ATOVS radiance on the intensity and track simulation of super-typhoon Fanapi(2010)using a data assimilation cycle method.The result indicates that the assimilation of ATOVS radiance could improve typhoon intensity effectively.The average bias of the central sea level pressure(CSLP)drops to 18 hPa,compared to 42 hPa in the experiment without data assimilation.However,the influence due to different radiance data is not significant,which is less than 6hPa on average,implying limited improvement from sole assimilation of ATOVS radiance.The track issue is studied in the following steps.First,the radiance from the same sensor of different satellites could produce different effect.For the AMSU-A,NOAA-15 and NOAA-18,they produce equivalent improvement,whereas NOAA-16 produces slightly poor effect.And for the AMSU-B,NOAA-15 and NOAA-16,they produce equivalent and more positive effect than that provided by the AMSU-A.Second,the assimilation radiance from different sensors of the identical satellites could also produce different effect.The assimilation of AMSU-B produces the largest improvement,while the ameliorating effect of HIRS/3assimilation is inferior to that of AMSU-B assimilation,while the AMSU-A assimilation exhibits the poorest improvement.Moreover,the simultaneous assimilation of different radiance could not produce further improvement.Finally,the experiments of simultaneous assimilation radiance from multiple satellites indicate that such assimilation may lead to negative effect due to accumulative bias when adding various radiance data into the data assimilation system.Thus the assimilation of ATOVS radiance from a single satellite may perform better than that from two or three satellites.     

卫星资料变分同化在一次中尺度强暴雨模拟中的应用

利用ATOVS资料和常规观测资料, 采用GRAPES 3D-Var同化系统和中尺度数值模式MM5设计了仅同化常规观测资料的NOATOVS试验和同化常规观测资料及ATOVS辐射率资料的ATOVS试验, 对2004年6月22—24日长江中下游和西南地区东部的特大暴雨进行了分析和模拟。结果表明:直接同化ATOVS辐射率资料获得的分析场可以有效改进对流层温、湿场分布, 对风场也有一定的影响。对比试验结果表明:ATOVS试验可以较好地模拟出暴雨天气形势、主要影响系统, 对降雨的落区、强度也有较好的反映, 模拟的局地暴雨强度与实际降雨量基本一致, 同化卫星资料的改善效果较为明显。即同化ATOVS资料对于改进中尺度局地暴雨过程模拟效果是可行的。     

The Effects of Assimilating Satellite Brightness Temperature and Bogus Data on the Simulation of Typhoon Kalmaegi (2008)

Observational and bogus satellite data are directly assimilated into the Weather Research and Forecasting (WRF) model in simulations of Typhoon Kalmaegi (2008). The data assimilation is performed using the Radiative Transfer for TIROS-N Operational Vertical Sounder (RTTOV) model and the three-dimensional variational data assimilation (3DVAR) technique, with satellite observations taken from the National Oceanic and Atmospheric Administration-16 (NOAA-16) Advanced TIROS Vertical Sounder (ATOVS) system composed of the High-resolution Infrared Radiation Sounder (HIRS), the Advanced Microwave Sounding Unit-A (AMSU-A), and the Advanced Microwave Sounding Unit-B (AMSU-B). Data assimilation experiments are initialized at three different times. Improvements in the numerical simulation of the typhoon are discussed in the context of wind, temperature, pressure, and geopotential fields. The results indicate that assimilation of satellite data can improve both the representation of the initial conditions and the subsequent simulation of the typhoon. Different satellite data have different impacts on the typhoon track. In these simulations, data from AMSU-A play a greater role in improving the simulation of the typhoon than data from AMSU-B or HIRS. Assimilation of satellite data significantly affects the simulation of the subtropical high and the steering of the typhoon by the environmental flow. The subtropical high is enhanced and extends westward in the data assimilation experiments. The background flow therefore steers the typhoon more westward, improving the simulated typhoon track. Although direct assimilation of satellite brightness temperature improves the simulated environmental conditions, it does not significantly improve the simulated intensity of the typhoon. By contrast, initializing the typhoon simulation using bogus data in tandem with satellite data improves not only the environmental conditions but also the simulated inner-core structure of the typhoon. Assimilation of both types of data therefore improves the simulation of both the typhoon track and the typhoon intensity. The results of these experiments offer new insight into improving numerical simulations of typhoons.     

Application of ATOVS Microwave Radiance Assimilation to Rainfall Prediction in Summer 2004

Experiments are performed in this paper to understand the influence of satellite radiance data on the initial field of a numerical prediction system and rainfall prediction. First, Advanced Microwave Sounder Unit A （AMSU-A） and Unit B （AMSU-B） radiance data are directly used by three-dimensional variational data assimilation to improve the background field of the numerical model. Then, the detailed effect of the radiance data on the background field is analyzed. Secondly, the background field, which is formed by application of Advanced Television and Infrared Observation Satellite Operational Vertical Sounder （ATOVS） microwave radiance assimilation, is employed to simulate some heavy rainfall cases. The experiment results show that the assimilation of AMSU-A （B） microwave radiance data has a certain impact on the geopotential height, temperature, relative humidity and flow fields. And the impacts on the background field are mostly similar in the different months in summer. The heavy rainfall experiments reveal that the application of AMSU-A （B） microwave radiance data can improve the rainfall prediction significantly. In particular, the AMSU-A radiance data can significantly enhance the prediction of rainfall above 10 mm within 48 h, and the AMSU-B radiance data can improve the prediction of rainfall above 50 mm within 24 h. The present study confirms that the direct assimilation of satellite radiance data is an effective way to improve the prediction of heavy rainfall in the summer in China.     

利用AMSU分析热带气旋结构特征

搭载在美国新一代极轨业务系列气象卫星上的先进的微波探测器 (Advanced Microwave Sounding Unit , AMSU) 提供了对于大气中温度、湿度以及云雨分布特征的探测能力。 研究选择 2003 年发生在西北太平洋上的多个热带气旋个例, 利用 NOAA16/17 卫星的 AMSU 数据分析热带气旋热力及云雨结构特征, 结果显示: 热带气旋中心的增暖在 AMSU-A 微波温度观测表现显著, 特别是在对流层上层通道尤其明显; AMSU 观测热带气旋中心增暖与强度相关性统计分析显示, 两者相关性达 0.778; AMSU-B 高频通道可以揭示热带气旋的云雨结构分布和对流发展旺盛情况, 分析显示热带气旋云雨结构变化与气旋强度密切相关, 气旋强度滞后于系统对流过程的发展 。     

Satellite Data Assimilation of Upper-Level Sounding Channels in HWRF with Two Different Model Tops

The Advanced Microwave Sounding Unit-A(AMSU-A) onboard the NOAA satellites NOAA-18 and NOAA-19 and the European Organization for the Exploitation of Meteorological Satellites(EUMETSAT)Met Op-A, the hyperspectral Atmospheric Infrared Sounder(AIRS) onboard Aqua, the High resolution Infra Red Sounder(HIRS) onboard NOAA-19 and Met Op-A, and the Advanced Technology Microwave Sounder(ATMS) onboard Suomi National Polar-orbiting Partnership(NPP) satellite provide upper-level sounding channels in tropical cyclone environments. Assimilation of these upper-level sounding channels data in the Hurricane Weather Research and Forecasting(HWRF) system with two different model tops is investigated for the tropical storms Debby and Beryl and hurricanes Sandy and Isaac that occurred in 2012. It is shown that the HWRF system with a higher model top allows more upper-level microwave and infrared sounding channels data to be assimilated into HWRF due to a more accurate upper-level background profile. The track and intensity forecasts produced by the HWRF data assimilation and forecast system with a higher model top are more accurate than those with a lower model top.     

基于卫星亮温资料同化对2009年热带风暴“浪卡”的数值研究

本文利用三维变分同化系统（WRFDA）,设计了4个同化试验方案,将ATOVS卫星亮温资料直接同化到中尺度数值模式（WRF）中,研究同化ATOVS不同卫星亮温资料对2009年04号热带风暴“浪卡”数值模拟的影响。结果表明,直接同化卫星亮温资料能够改善初始场结构（大气流场、温度场）,尤其是对西太平洋反气旋系统,进而提高对热带气旋路径的模拟精度。同化不同类型的ATOVS卫星亮温资料对于热带气旋的移动路径有着不同程度的改善,其中以HIRS3和HIRS4资料同化对热带气旋移动路径改善效果最好。