区域GPS网对夏季降雨过程中大气可降水量的探测     

黄官永 《地理空间信息》2010,8(3):53-55,105

利用GPS网的观测资料,通过GAMIT软件求得5个测站对流层天顶总延迟,进而求出各测站对流层湿延迟;利用湿延迟与大气可降水量之间的转换关系得到各测站的大气可降水量。将所得GPS-PWV值与同时段探空资料所得的大气可降水量以及地表实际降水量进行对比分析,结果表明:GPS-PWV值与探空资料所得的PWV值比较相符;在降水前后,GPS-PWV有比较明显的变化,降水一般出现在GPS-PWV值迅速增加的4-6h内;实际降水量峰值与GPS-PWV增量大小也有较强的相关性。  相似文献   

实时格网对流层模型在中国区域的适用性分析     

杨元元  李薇  张红星  周冲冲  鲍李峰 《大地测量与地球动力学》2019,39(4):410-416

利用无线电探空数据，对格网对流层模型GPT2w、IGGtrop及GTPs在中国区域的适用性进行分析。结果显示，GPT2w和IGGtrop在地表附近精度相当，RMS为4.0~4.2 cm，西部地区精度优于东部，东南沿海精度最差，夏季精度明显低于冬季，在中西部地区分辨率低的模型可能会产生异常偏差；GPT2w模型明显存在系统性偏差，中西部为正，东南部为负；3 km高度以上，IGGtrop模型精度明显优于GPT2w模型，且随高度增加精度保持稳定。在飞行器定位导航中，建议采用IGGtrop模型修正ZTD误差。GTPs模型时间分辨率高，精度明显优于传统的经验模型，尤其在东南沿海ZTD变化剧烈的区域，但由于其依赖于外部数据源，部分区域无法使用。  相似文献   

FY-3C VIRR大气可降水产品生成和检验     

胡菊旸  唐世浩  刘海磊  郑婧 《遥感学报》2017,21(6):842-852

风云三号C星(FY-3C)可见光红外扫描辐射计(VIRR)两个红外分裂窗通道数据生成的晴空大气可降水(TPW)产品已投入业务使用。本文介绍了该产品的生成方法,并从产品精度和稳定性两个方面评价产品质量。与MODIS Terra TPW的月平均数据对比,FY-3C VIRR TPW能正确反应大气可降水的全球分布。与2015年3月—4月的全球探空数据对比,FY-3C VIRR TPW均方根误差为5.36 mm,相对误差在水汽值大于30 mm时在20%以内,并且夜间产品精度优于白天。相比于MODIS红外TPW产品与探空数据的误差,FY-3C TPW精度略好。计算2015年1月至2016年7月FY-3C VIRR TPW产品相对探空数据的月均方根误差,19个月均方根误差的标准差是0.54 mm,小于同期MODIS Terra TPW均方根误差的标准差,说明FY-3C VIRR TPW产品在检验时期内更稳定。FY-3C VIRR TPW产品精度较高且质量稳定,具备广泛应用能力。  相似文献   

我国飞机观测气温和常规高空观测气温的对比分析     

廖捷  任芝花 《气象》2011,37(3):263-269

对2006年1月至2009年12月的飞机观测气温资料进行了质量控制,在此基础上通过其和常规高空气温资料的对比分析对飞机观测气温的可用性进行了评估.我国绝大部分飞机观测资料由B737-800和B737-700型飞机观测而得.统计结果表明:两种型号飞机的观测气温和常规高空观测气温的差值分布存在一定差异;差值呈准对称分布,64%的差值分布在-1℃至1℃;不同高度层上的差值不同.相对于常规高空观测气温,飞机观测气温值在700 hPa及以下偏低,在500 hPa及以上偏高.飞机观测气温和常规高空观测气温的差值大小和飞机型号及飞行状态有关.以北京地区的资料为例,利用北京首都机场上空飞机观测气温统计得到的月值和北京探空站常规高空观测气温月值没有显著性差异,各层次、时次的月值差异基本维持在-1℃至0.5℃之间.  相似文献   

用初估场对比中芬探空仪温度和位势高度记录   总被引：4，自引：3，他引：1       下载免费PDF全文

马颖  姚雯  黄炳勋 《应用气象学报》2011,22(3):336-345

对部分高空台站2007—2009年近3年探空记录的统计分析表明:邻近测站同一型号探空仪的温度和位势高度记录与6 h数值预报初估场的平均偏差一致,但不同型号探空仪记录与初估场的平均偏差存在明显差异,因此可以利用初估场进行邻近测站不同型号探空仪之间的间接对比。该文利用初估场与台站探空记录的差值,分析了使用芬兰Vaisala公司RS92型探空仪的中国香港站与邻近的使用L波段探空仪的梧州、汕头、东源、阳江4站2年的温度和位势高度记录的系统差,结果表明:19:00(北京时,下同),L波段探空仪的温度和位势高度记录在平流层分别偏低达1℃和30 gpm;07:00,L波段探空仪的温度记录在对流层偏高0.4℃,导致其位势高度记录也在对流层偏高;两套设备的系统差不仅有显著的日夜差异和季节性差异,也存在一定的年际差异。  相似文献   

国产珠状温度传感器对比分析     

李伟 《南京气象学院学报》2011,(4):346-353

通过比对试验,采取同球比对施放方式,选择德国GRAW探空仪作为比对标准,使用总共12次同球比对数据,对中国长峰、华云和大桥3种型号探空仪的珠状电阻温度传感器开展比对分析.经典型个例分析与统计分析表明:3个型号国产探空仪高空温度廓线与德国GRAW探空仪具有较好的整体一致性,温度测量夜间性能均好于白天;长峰探空仪温度探测性能随高度变化比较稳定,而华云探空仪与大桥探空仪性能相仿,均随高度性能下降,尤其是30km以上高空;长峰探空仪温度探测整体性能最好,相对系统误差在0.2℃左右;而华云探空仪与大桥探空仪误差可达1℃,且均表现为整体上温度测值偏低.体积较小的珠状温度传感器将是未来高空温度探测的一个好的选择,下一步需要改善华云探空仪与大桥探空仪温度传感器表面涂层工艺,两者的温度辐射订正算法也需要进一步完善.  相似文献   

Intercomparison of Humidity and Temperature Sensors: GTS1, Vaisala RS80, and CFH   总被引：8，自引：0，他引：8  

BIAN Jianchun  CHEN Hongbin  Holger VOMEL  DUAN Yunjun  XUAN Yuejian  LU Daren 《大气科学进展》2011,28(1):139-146

GTS1 digital radiosonde, developed by the Shanghai Changwang Meteorological Science and Technology Company in 1998, is now widely used in operational radiosonde stations in China. A preliminary comparison of simultaneous humidity measurements by the GTS1 radiosonde, the Vaisala RS80 radiosonde, and the Cryogenic Frostpoint Hygrometer (CFH), launched at Kunming in August 2009, reveals a large dry bias produced by the GTS1 humidity sensor. The average relative dry bias is in the order of 10% below 500 hPa, increasing rapidly to 30% above 500 hPa, and up to 55% at 310 hPa. A much larger dry bias is observed in the daytime, and this daytime effect increases with altitude. The GTS1 radiosonde fails to respond to humidity changes in the upper troposphere, and sometimes even in the middle troposphere. The failure of GTS1 in the middle and upper troposphere will result in significant artificial humidity shifts in radiosonde climate records at stations in China where a transition from mechanical to digital radiosondes has occurred. A comparison of simultaneous temperature observations by the GTS1 radiosonde and the Vaisala RS80 radiosonde suggests that these two radiosondes provide highly reproducible temperature measurements in the troposphere, but produce opposite biases for daytime and nighttime measurements in the stratosphere. In the stratosphere, the GTS1 shows a warm bias (<0.5 K) in the daytime and a relatively large cool bias (-0.2 K to -1.6 K) at nighttime.  相似文献   

Investigating the Dominant Source for the Generation of Gravity Waves during Indian Summer Monsoon Using Ground-based Measurements     

Debashis NATH  CHEN Wen 《大气科学进展》2013,30(1):153-166

Over the tropics,convection,wind shear(i.e.,vertical and horizontal shear of wind and/or geostrophic adjustment comprising spontaneous imbalance in jet streams) and topography are the major sources for the generation of gravity waves.During the summer monsoon season(June-August) over the Indian subcontinent,convection and wind shear coexist.To determine the dominant source of gravity waves during monsoon season,an experiment was conducted using mesosphere-stratosphere-troposphere(MST) radar situated at Gadanki(13.5 N,79.2 E),a tropical observatory in the southern part of the Indian subcontinent.MST radar was operated continuously for 72 h to capture high-frequency gravity waves.During this time,a radiosonde was released every 6 h in addition to the regular launch(once daily to study low-frequency gravity waves) throughout the season.These two data sets were utilized effectively to characterize the jet stream and the associated gravity waves.Data available from collocated instruments along with satellite-based brightness temperature(TBB) data were utilized to characterize the convection in and around Gadanki.Despite the presence of two major sources of gravity wave generation(i.e.,convection and wind shear) during the monsoon season,wind shear(both vertical shear and geostrophic adjustment) contributed the most to the generation of gravity waves on various scales.  相似文献   

基于第8届国际探空比对试验对GTS1 2型探空仪技术改进与对比分析     

郭启云  李伟  张玉存 《气象科技》2013,41(3):453-458

经过国内学者和WMO的评估,GTS1 2型探空仪需要进行技术改进以适应高空气象观测业务的发展需求。2012年,GTS1 2型探空仪在原体制基础上进行了技术改进(暂命名为GTS1 2A型)。2012年8月在阳江探空站开展比对试验,试验结果表明：GTS1 2A型探空仪夜间温度测量性能良好,系统误差在-03 ℃以内,标准偏差总体上在02 ℃左右;日间温度除探测中高层和出入云时外,系统误差整体上在-03 ℃,标准偏差整体上在04 ℃以内;气压除近地层有约-15 hPa的系统误差外,整体上系统误差和标准偏差小于GTS1 2型探空仪,尤其标准偏差在全量程范围内在07 hPa以内;GTS1 2A型探空仪湿度测量结果与RS92型探空仪一致性较好,灵敏度明显优于GTS1 2型探空仪,系统误差和标准偏差整体上均在10%RH以内。  相似文献   

Atmospheric River Signatures in Radiosonde Profiles and Reanalyses at the Dronning Maud Land Coast,East Antarctica     

Irina V.GORODETSKAYA  Tiago SILVA  Holger SCHMITHUSEN  Naohiko HIRASAWA 《大气科学进展》2020,37(5):455-476

Atmospheric rivers(ARs)are an important component of the hydrological cycle linking moisture sources in lower latitudes to the Antarctic surface mass balance.We investigate AR signatures in the atmospheric vertical profiles at the Dronning Maud Land coast,East Antarctica,using regular and extra radiosonde measurements conducted during the Year of Polar Prediction Special Observing Period November 2018 to February 2019.Prominent AR events affecting the locations of Neumayer and Syowa cause a strong increase in specific humidity extending through the mid-troposphere and a strong low-level jet(LLJ).At Neumayer,the peak in the moisture inversion(up to 4 g kg^?1)is observed between 800 and 900 hPa,while the LLJ(up to 32 m s^?1)is concentrated below 900 hPa.At Syowa the increase in humidity is less pronounced and peaks near the surface,while there is a substantial increase in wind speed(up to 40 m s?1)between 825 and 925 hPa.Moisture transport(MT)within the vertical profile during the ARs attains a maximum of 100 g kg?1 m s?1 at both locations,and is captured by both ERA-Interim and ERA5 reanalysis data at Neumayer,but is strongly underestimated at Syowa.Composites of the enhanced MT events during 2009?19 show that these events represent an extreme state of the lower-tropospheric profile compared to its median values with respect to temperature,humidity,wind speed and,consequently,MT.High temporal-and vertical-resolution radiosonde observations are important for understanding the contribution of these rare events to the total MT towards Antarctica and improving their representation in models.  相似文献