基于无线电探空的武汉大气加权平均温度模型研究     

王勇  杨彬云  刘严萍  胡小刚  柳林涛  许厚泽 《测绘科学》2010,35(2):112-113,108

以武汉地区为例,本文推导无线电探空推导的大气加权平均温度模型并对其可靠性进行检验。采用武汉无线电探空数据推算武汉地区的大气加权平均温度计算模型,以此模型计算GPS可降水量,通过与无线电探空结果比较来检验该模型的精确度。在WHDH站GPS可降水量与无线电探空的比较中,两者差值的均方根为3.0mm,两者的相关性达到了0.952。利用中国地壳运动监测网络2002年武汉站GPS数据和武汉地区大气加权平均温度模型推算的可降水量与无线电探空比较,GPS可降水量与无线电探空可降水量在数值上和发展趋势上比较接近,说明了无线电探空的大气加权平均温度模型的可靠性。  相似文献   

中国区域夏季再分析资料高空变量可信度的检验   总被引：5，自引：0，他引：5       下载免费PDF全文

韦芬芬  汤剑平  王淑瑜 《地球物理学报》2015,58(2):383-397

利用全球探空资料(IGRA)对1989—2008年美国国家环境预报中心(NCEP)和大气研究中心(NCAR)再分析资料、NCEP和美国能源部(DOE)再分析资料、NCEP气候预测系统再分析资料(CFSR)、日本气象厅25年再分析资料(JRA-25)、欧洲数值预报中心再分析资料(ERA-Interim)和美国国家航空航天局(NASA)现代回顾性再分析资料(MERRA)的高空变量在中国地区对流层中高层的可信度进行了初步的检验.分析结果表明:再分析资料对中高层位势高度和温度的夏季平均气候态具有较好的再现能力,其EOF的时空变化特征与观测吻合也较好;再分析资料的绝对湿度值较观测结果要偏大,其中MERRA与观测最为接近.再分析资料不能很好地反映经向风的夏季平均气候态及年际变化特征,EOF的时空模态和观测偏离也较大.总体而言,NCEP/NCAR、NCEP/DOE及NCEP/CFSR对这些变量的再现能力较JRA-25、ERA-Interim和MERRA弱.  相似文献   

中国传统农区过去300年耕地重建结果的对比分析   总被引：12，自引：4，他引：8  

何凡能  李士成  张学珍  葛全胜  戴君虎 《地理学报》2012,67(9):1190-1200

土地覆被变化是气候与生态效应模拟研究的重要参量。SAGE和HYDE两个全球历史土地利用数据集在相关研究中得到广泛应用, 但在区域尺度上的应用, 其可靠性如何, 至今少有论及。以我国学者重建的传统农区历史耕地数据集(CHCD) 为基础, 从全区、省区和网格(60 km×60 km) 三个空间尺度, 对SAGE (2010) 和HYDE3.1 数据集中有关中国传统农区历史耕地重建结果进行对比分析, 结果表明:(1) SAGE (2010) 数据集对中国传统农区耕地数量重建是以单一线性插补而得, 其中1700-1950 年是以0.51%的年均增长率线性递增, 1950 年后是以0.34%年均速率线性递减, 这种“标准化”变化趋势不能客观反映传统农区土地垦殖的真实历史, 耕地面积也明显高估, 与CHCD数据集不具有可比性;(2) HYDE3.1 数据集吸纳了区域性研究成果, 使其在总量上与CHCD数据集较为接近, 具有较好的可比性, 但其在省区和网格尺度上与CHCD存在显著差异, 其中相对差异率超过70% (< -70%或> 70%) 的网格占比高达56%~63%, 超过90% (< -90%或> 90%) 的网格占比也高达40%~45%;而相对差异率介于-10%~10%的网格占比仅为5%~6%, 介于-30%~30%的网格占比也仅为17%左右;(3) 充分利用我国丰富的历史文献, 建立更高精度的中国区域历史土地利用数据集, 是提高区域气候与生态效应模拟研究质量的重要保障。  相似文献   

Spatio-temporal evaluation of global gridded precipitation datasets across Iran   总被引：1，自引：0，他引：1  

Seyed-Mohammad Hosseini-Moghari  Kumars Ebrahimi 《水文科学杂志》2013,58(11):1669-1688

ABSTRACT

In this work, the accuracy of four gridded precipitation datasets – Climatic Research Unit (CRU), Global Precipitation Climatology Centre (GPCC), PERSIANN-Climate Data Record (PCDR) and University of Delaware (UDEL) – is evaluated across Iran to find an alternative source of precipitation data. Monthly, seasonal and annual precipitation data from 85 synoptic stations for the period 1984–2013 were used as the basis for the evaluations. Our results indicate that all datasets underestimate and overestimate precipitation in stations with annual precipitation greater than 600 and less than 100 mm, respectively. However, all datasets correctly recognize regimes of precipitation, but with a bias in amount of precipitation. Our spatio-temporal assessments show that GPCC is the most suitable dataset to be used over Iran. Both UDEL and CRU can be considered as the second and third most suitable datasets, while PCDR showed the weakest performance among the studied datasets.  相似文献   

基于直方变差图的土地覆盖数据集多尺度精度评价     

朱榴骏  肖鹏峰  冯学智  汪左  蒋璐媛 《遥感学报》2013,17(6):1459-1474

针对目前精度评价尺度单一的问题,提出基于直方变差图的多尺度精度评价方法,分别在像元尺度和亚像元尺度进行土地覆盖数据集精度评价。在像元尺度利用驻点作为采样工具直接评价数据集精度;亚像元尺度上,则利用非严格定义的驻点和驻点直方变差图对不同面积和空间结构的优势类进行精度评价。并以浙江北部典型区域为实验区,Landsat TM/ETM+为参考数据,对UMD、IGBP DISCover、MOD12Q1-2001、GLC2000、GlobCover2009等5种大尺度土地覆盖数据集进行多尺度精度评价实验。结果表明,多尺度精度评价方法能够全面地评价土地覆盖数据集的精度,提供更加丰富的多尺度精度信息。像元尺度精度评价可在一定程度上消除由于参考数据与数据集间的空间匹配造成的误差,评价结果更加客观;亚像元尺度精度评价能有效反映亚像元尺度优势地物面积及空间结构与精度的关系。  相似文献   

Comprehensive Marine Observing Experiment Based on High-Altitude Large Unmanned Aerial Vehicle(South China Sea Experiment2020 of the “Petrel Project”)     

Xuefen ZHANG  Liangxu LI  Rongkang YANG  Ran GUO  Xia SUN  Jianping LUO  Hongbin CHEN  Daxin LIU  Kebing TANG  Wenwu PENG  Xiaodong HAN  Qiyun GUO  Xiaoxia LI  Xikun FEI 《大气科学进展》2021,38(4):531-537

In collaboration with 12 other institutions, the Meteorological Observation Center of the China Meteorological Administration undertook a comprehensive marine observation experiment in the South China Sea using the Yilong-10 high-altitude large unmanned aerial vehicle(UAV). The Yilong-10 UAV carried a self-developed dropsonde system and a millimeter-wave cloud radar system. In addition, a solar-powered unmanned surface vessel and two drifting buoys were used. The experiment was further supported by an intelligent, reciprocating horizontal drifting radiosonde system that was deployed from the Sansha Meteorological Observing Station, with the intent of producing a stereoscopic observation over the South China Sea. Comprehensive three-dimensional observations were collected using the system from 31 July to2 August, 2020. This information was used to investigate the formation and development processes of Typhoon Sinlaku(2020). The data contain measurements of 21 oceanic and meteorological parameters acquired by the five devices, along with video footage from the UAV. The data proved very helpful in determining the actual location and intensity of Typhoon Sinlaku(2020). The experiment demonstrates the feasibility of using a high-altitude, large UAV to fill in the gaps between operational meteorological observations of marine areas and typhoons near China, and marks a milestone for the use of such data for analyzing the structure and impact of a typhoon in the South China Sea. It also demonstrates the potential for establishing operational UAV meteorological observing systems in the future, and the assimilation of such data into numerical weather prediction models.  相似文献   

强对流风暴中同质冻结增温的直接探空观测     

徐小红  余兴  戴进  刘贵华  朱延年  岳治国 《南京气象学院学报》2011,34(4):416-422

通过两个强对流风暴个例,利用探空资料辅以卫星反演方法,揭示了强对流风暴中同质冻结增温这一事实。探空观测到在强风暴中同质冻结潜热释放造成该层内的空气增温达5℃以上,风暴中强上升气流使云滴没有足够的时间长大,云水向雨水转化和云的晶化会被推到更高的高度,在到达同质冻结高度之前,异质核化过程没有太多的时间消耗大量云水,多数云滴被带到同质冻结高度以上时迅速冻结,造成潜热的集中释放,使周围的空气增温。NOAA卫星观测到的云顶的大量由同质冻结形成的小冰粒子以及过顶现象,进一步证实了同质冻结潜热增温。当探空仪靠近风暴、对流层顶又距同质冻结高度层较近时,同质冻结增温作用有可能被探空仪观测到。  相似文献   

杭州L波段和59-701高空探测系统资料对比分析   总被引：1，自引：0，他引：1  

朱兰娟  华行祥 《气象科技》2007,35(5):750-754

为比较L波段高空探测系统和59-701高空探测系统的资料异同,采用平均差、均方差比较的方法分析了杭州站平行观测一个月资料的温压湿资料,比较其异同及产生原因,为更好利用高空探测资料、改进L波段高空探测系统提供参考。通过比较发现:L波段高空探测系统比59-701高空探测系统所测的温度、高度资料更稳定、离散率更小,对提高预报准确率有利。两套系统的温度差值在70 hPa层出现明显拐点,其原因有待进一步研究。  相似文献   

AMDAR气温资料和常规高空观测气温资料的对比分析     

罗林艳  罗宇  钟艳雯 《气象与环境科学》2018,41(3):117-121

为了解飞机观测气象资料(AMDAR资料)的可用性,推进AMDAR资料在湖南气象预报业务中的应用,对2013年5月至2016年12月的AMDAR资料时空分布特征进行了分析,并参考美国国家环境预报中心(NCEP)提供的AMDAR资料质量控制方法,对AMDAR气温资料进行质量控制,并在此基础上对湖南范围内的AMDAR气温资料和常规高空观测气温资料(长沙、怀化、郴州)进行了对比分析。结果表明:我国AMDAR资料主要分布在100 h Pa气压层以下,起飞和降落阶段资料约占68. 75%。AMDAR气温资料数据质量稳定,气温疑误率低于0. 13%。在对比样本上,AMDAR观测气温(t_a)与常规高空观测气温(ts)存在非常显著相关性,相关系数为0. 9966,均方根误差为1. 065℃,AMDAR观测气温平均偏低0. 13℃,差值呈准正态分布,且73. 76%的差值在-1~1℃。AMDAR观测气温与常规高空观测气温的差值分布与飞行状态和飞行高度相关,上升状态AMDAR气温偏高,下降状态AMDAR气温偏低。500 h Pa高度以下,样本飞行状态多为下降,t_a较ts平均偏低0. 25℃; 500h Pa高度以上,样本飞行状态多为上升和平飞,t_a较ts平均偏高0. 03℃。  相似文献   

Climatology of Cloud-base Height from Long-term Radiosonde Measurements in China     

Yong ZHANG  Lejian ZHANG  Jianping GUO  Jinming FENG  Lijuan CAO  Yang WANG  Qing ZHOU  Liangxu LI  Bai LI  Hui XU  Lin LIU  Ning AN  Huan LIU 《大气科学进展》2018,35(2):158-168

Clouds are critical to the global radiation budget and hydrological cycle, but knowledge is still poor concerning the observed climatology of cloud-base height(CBH) in China. Based on fine-resolution sounding observations from the China Radiosonde Network(CRN), the method used to estimate CBH was modified, and uncertainty analyses indicated that the CBH is good enough. The accuracy of CBH estimation is verified by the comparison between the sounding-derived CBHs and those estimated from the micro-pulse lidar and millimeter-wave cloud radar. As such, the CBH climatology was compiled for the period 2006–16. Overall, the CBH exhibits large geographic variability across China, at both 0800 Local Standard Time(LST) and 2000 LST, irrespective of season. In addition, the summertime cloud base tends to be elevated to higher altitudes in dry regions [i.e., Inner Mongolia and the North China Plain(NCP)]. By comparison, the Tibetan Plateau(TP),Pearl River Delta(PRD) and Sichuan Basin(SCB) have relatively low CBHs( 2.4 km above ground level). In terms of seasonality, the CBH reaches its maximum in summer and minimum in winter. A low cloud base tends to occur frequently( 70%) over the TP, PRD and SCB. In contrast, at most sites over the Yangtze River Delta(YRD) and the NCP, about half the cloud belongs to the high-cloud category. The CBH does not exhibit marked diurnal variation in summer, throughout all CRN sites, probably due to the persistent cloud coverage caused by the East Asia Summer Monsson. To the best of our knowledge, this is the first CBH climatology produced from sounding measurements in China, and provides a useful reference for obtaining observational cloud base information.  相似文献