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1.
中国降水测量误差的研究 总被引：19，自引：0，他引：19
20世纪 ,国际上许多国家对降水测量进行了对比试验工作 ,以研究降水测量中的误差大小与分布。由于各个国家降水测量仪器的型式、尺寸以及安装高度不同 ,试验对比的降水测量误差的大小也就不同。为了弄清中国降水测量误差的大小 ,中国气象局选择了 30个基准基本站 ,建立标准雨量站网进行试验对比。本文介绍了中国标准雨量站网的设置以及对比资料的获取情况 ,对比分析了中国降水测量的随机误差、沾湿与蒸发误差、风场变形误差。经 30个标准雨量站 7a 2 90 0 0多次的 1台坑式雨量器、2台台站雨量器的对比观测 ,给出了中国降水量测量误差的大小、降水测量中的随机误差与系统误差的分布情况。经分析 ,对于收集口口径为 2 0cm ,安装高度为 70cm的台站普通雨量器 ,每次测量随机误差累计平均值为 0 .0mm ,沾湿误差为 0 .2mm ,蒸发误差为 0 .0mm ,降雨风场变形误差为 0 .19mm ,降雪为 0 .32mm。降雨测量的平均相对误差约为 4 .34%～ 15 .2 8% ,降雪测量的平均相对误差约为 6 .17%～ 39.99%。 相似文献
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Long-term snow and weather observations at Weissfluhjoch and its relation to other high-altitude observatories in the Alps 总被引：1，自引：1，他引：0
Snow and weather observations at Weissfluhjoch were initiated in 1936, when a research team set a snow stake and started digging snow pits on a plateau located at 2,540?m asl above Davos, Switzerland. This was the beginning of what is now the longest series of daily snow depth, new snow height and bi-monthly snow water equivalent measurements from a high-altitude research station. Our investigations reveal that the snow depth at Weissfluhjoch with regard to the evolution and inter-annual variability represents a good proxy for the entire Swiss Alps. In order to set the snow and weather observations from Weissfluhjoch in a broader context, this paper also shows some comparisons with measurements from five other high-altitude observatories in the European Alps. The results show a surprisingly uniform warming of 0.8°C during the last three decades at the six investigated mountain stations. The long-term snow measurements reveal no change in mid-winter, but decreasing trends (especially since the 1980s) for the solid precipitation ratio, snow fall, snow water equivalent and snow depth during the melt season due to a strong temperature increase of 2.5°C in the spring and summer months of the last three decades. 相似文献
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Abstract Most water balance studies in the High Arctic indicate that the weather stations underestimate annual precipitation, but the magnitude of such error is unknown. Based on up to seven years of field measurements, this study provides a comparison of snowfall at weather stations with the winter snow accumulation in their nearby drainage basins. Snowfall is the major form of precipitation in the polar region for nine months every year. Without vegetation, snowdrift is controlled by the local terrain. By establishing the snow characteristics for different terrain types, total basin snow storage can be obtained by areally weighting the snow cover for various terrain units in the basin. Such a method was successfully employed to compute total winter snowfall in the drainage basins near Resolute, Eureka and Mould Bay. Results show that the basins had 130 to 300per cent more snow than the weather stations recorded. Using revised snowfall values that are reinforced by Koerner's snow core measurements from ice‐caps, it is hoped that a more realistic precipitation map can be provided for the High Arctic. 相似文献
5.
利用19种不同型号的自动雨量站2005年6—9月在北京 (54511)、宜昌 (57461) 和南京 (58238) 3站的实测对比观测资料, 进行降雨资料质量评估, 不同的评估方法将会导致评估结果的差异。结果表明:采用自动气象站降雨资料和雨量筒人工定时观测记录作为降雨量参考标准对自动雨量站进行评估时, 由于降雨量参考标准本身存在的不确定性, 或多或少影响了评估结果的准确性。在广泛试验的基础上, 提出了采用基于各自动雨量站观测结果的拟合降雨量作为降雨量参考标准的新思路, 并对拟合降雨量的可行性、适用性以及计算方法进行了详细论述。 相似文献
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Massimo Frezzotti Michel Pourchet Onelio Flora Stefano Gandolfi Michel Gay Stefano Urbini Christian Vincent Silvia Becagli Roberto Gragnani Marco Proposito Mirko Severi Rita Traversi Roberto Udisti Michel Fily 《Climate Dynamics》2004,23(7-8):803-813
Surface mass balance (SMB) distribution and its temporal and spatial variability is an essential input parameter in mass balance studies. Different methods were used, compared and integrated (stake farms, ice cores, snow radar, surface morphology, remote sensing) at eight sites along a transect from Terra Nova Bay (TNB) to Dome C (DC) (East Antarctica), to provide detailed information on the SMB. Spatial variability measurements show that the measured maximum snow accumulation (SA) in a 15 km area is well correlated to firn temperature. Wind-driven sublimation processes, controlled by the surface slope in the wind direction, have a huge impact (up to 85% of snow precipitation) on SMB and are significant in terms of past, present and future SMB evaluations. The snow redistribution process is local and has a strong impact on the annual variability of accumulation. The spatial variability of SMB at the kilometre scale is one order of magnitude higher than its temporal variability (20–30%) at the centennial time scale. This high spatial variability is due to wind-driven sublimation. Compared with our SMB calculations, previous compilations generally over-estimate SMB, up to 65% in some areas. 相似文献
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Snow/Rainfall Anomaly in Winter of Northern China and Associated Atmospheric Circulation and Aerosol Distribution Features 
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下载免费PDF全文 Based on the NCEP/NCAR reanalysis data,China station precipitation data from 1960 to 2008,and aerosol optical depth (AOD) data in northern China from 1980 to 2004,this paper investigates the variability of winter snow/rainfall in northern China and the associated atmospheric circulation and aerosol distribution characteristics by using composite analysis.The results show that winter precipitation in northern China has been generally increasing since the 1960s.Among the winters of 1990-2008,the years with more rain/snow (MRSYs) are 1998,2003,and 2006,while the years with less rain/snow (LRSYs) are 2005,1997,and 2001.Composite analysis finds that the main differences of atmospheric circulation in East Asia between MRSYs and LRSYs are as follows.1) In MRSYs,strong low-level cold air over the northern polar region and Taymyr Peninsula migrates southward to northern China (Northwest,North,and Northeast China),establishing a channel favoring continuous southward transport of cold air.In LRSYs,however,this cold air channel does not exist.2) In MRSYs,the frontal zone and westerlies are over North China,and the low-level geopotential height field from eastern China to West Pacific exhibits an "east high,west low" pattern,which is conducive to easterly and southerly airflows moving northward along 110 E.In LRSYs,the 500-hPa prevailing westerly winds stay far away from China and the low-level southeasterlies move to higher latitudes,which are disadvantageous to the development of precipitation in northern China.3) In MRSYs,large-scale upward motions combined with local-scale updrafts develop into strong slanted climbing airflows,forming a vertical circulation that favors the generation of heavy snows in eastern China.In LRSYs,the vertical circulation moves eastward into the Pacific Ocean.Furthermore,the correlation analysis on AOD and winter precipitation during the period 1980-2004 in northern China reveals that AOD differs significantly between MRSYs and LRSYs and the annual variation of winter rain/snow is positively correlated to the annual variation of AOD with a correlation coefficient of 0.415 at the 0.001 significance level. 相似文献
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适用于全国自动站小时降水资料的质量控制方法 总被引：28，自引：2，他引：26
区域自动站逐小时降水资料对于气象预警、决策服务、预报验证等非常重要。资料在提供使用前其质量状况应是可知的。在制作的区域自动站逐小时降水资料数据集基础上,并结合国家级台站观测的小时降水资料,通过深入分析错误数据的存在方式,研制形成全国自动站逐小时降水资料质量控制方案。该方案适用于全国范围内区域站和国家站,实时和非实时上传的逐小时降水资料自动质量控制。最后介绍了利用该方案对2006—2009年实时上传的全国自动站小时降水资料的质量评估结果。 相似文献
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采用1962-2008年辽宁省52个气象观测站逐日积雪深度以及同期温度、降水资料,用统计方法和小波方法分析了辽宁省积雪气候变化规律。结果表明：近47 a辽宁省积雪日数呈不显著增加趋势,共增加了3 d;年最大雪深随时间变化呈不明显增加趋势,平均每10 a增加0.2 cm;年累积雪深也呈不显著增加趋势,气候倾向率为8.9 cm/10 a。从年代际变化来看,20世纪80年代前辽宁省积雪日数、年最大雪深和年累积雪深偏小;而20世纪80年代后至今,则经历了一个积雪日数、年最大雪深和年累积雪深均增加的过程。 相似文献
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In this study, efforts are made to improve the simulation of heavy rainfall events over National Capital Region (NCR) Delhi during 2010 summer monsoon, using additional observations from automatic weather stations (AWS). Two case studies have been carried out to simulate the relative humidity, wind speed and precipitation over NCR Delhi in 48-h model integrations; one from 00UTC, August 20, 2010, and the other from 00UTC, September 12, 2010. Several AWS installed over NCR Delhi in the recent past provide valuable surface observations, which are assimilated into state-of-the-art weather research and forecasting (WRF) model using the three-dimensional variational data assimilation (3DVAR). The quality of background error statistics (BES) is a key component in successful 3DVAR data assimilation in a mesoscale model. In this study, the domain-dependent regional background error statistics (RBS) are estimated using National Meteorological Center method in the months of August and September 2010 and then compared with the global background error statistics (GBS) in the WRF model. The model simulations are analyzed and validated against AWS and radiosonde observations to quantify the impact of RBS. The root mean square differences in the spatial distributions of precipitation, relative humidity and wind speed at the surface showed significant differences between both the global and regional BES. Similar differences are also observed in the vertical distributions along the latitudinal cross section at 28.5°N. Model-simulated fields are analyzed at five different surface stations and one upper air station located in NCR Delhi. It is found that in 24-h model simulation, the RBS significantly improves the model simulations in case of precipitation, relative humidity and wind speed as compared to GBS. 相似文献
12.
YANG Xingguo QIN Dahe ZHANG Tingjun KANG Shichang QIN Xiang LIU Hongyi 《Acta Meteorologica Sinica》2010,24(6):680-698
Ground-based measurements are essential for understanding alpine glacier dynamics, especially in remote
regions where in-situ measurements are extremely limited. From 1 May to 22 July 2005 (the spring-summer
period), and from 2 October 2007 to 20 January 2008 (the autumn-winter period), surface radiation as well
as meteorological variables were measured over the accumulation zone on the East Rongbuk Glacier of Mt.
Qomolangma/Everest at an elevation of 6560 m a.s.l. by using an automatic weather station (AWS). The
results show that surface meteorological and radiative characteristics were controlled by two major synoptic
circulation regimes: the southwesterly Indian monsoon regime in summer and the westerlies in winter. At the
AWS site on the East Rongbuk Glacier, north or northwest winds prevailed with high wind speed (up to 35 m
s-1 in January) in winter while south or southeast winds predominated after the onset of the southwesterly
Indian monsoon with relatively low wind speed in summer. Intensity of incoming shortwave radiation was
extremely high due to the high elevation, multiple reflections between the snow/ice surface and clouds, and
the high reflective surrounding surface. These factors also caused the observed 10-min mean solar radiation
fluxes around local noon to be frequently higher than the solar constant from May to July 2005. The mean
surface albedo ranged from 0.72 during the spring-summer period to 0.69 during the autumn-winter period.
The atmospheric incoming longwave radiation was greatly affected by the cloud condition and atmospheric
moisture content. The overall impact of clouds on the net all-wave radiation balance was negative in the Mt.
Qomolangma region. The daily mean net all-wave radiation was positive during the entire spring-summer
period and mostly positive during the autumn-winter period except for a few overcast days. On monthly
basis, the net all-wave radiation was always positive. 相似文献
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春季一次暴雪过程的多普勒雷达动力学诊断 总被引：1，自引：1，他引：1
利用太原C波段多普勒天气雷达基数据资料和自动雨量站资料，对2006年4月11日发生在山西省的一次区域性暴雪过程进行了分析。应用改进的EVAD技术，定量计算垂直高度层的平均散度和平均垂直速度，并分析平均散度和平均垂直速度随时间和高度的变化以及与降雪的对应关系。结果表明：2．5km以下始终维持一个较强的上升气流，是强降雪维持的基本动力条件；整层出现辐合上升运动，且强上升速度中心的高度随时间的演变逐渐下降，同时中高层出现强辐散下沉气流与之配合时，未来2小时将出现强降雪；降雪的强度与雷达探测范围内各高度层的辐舍、辐散有着密切的关系，且辐合、辐散的增强与减弱时间早于降雪强度的增大和减小时间，这对预报降雪的生消、雪强的增大与减小提供了一定的理论依据。 相似文献
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《Atmospheric Research》2008,87(3-4):330-339
The aim of the present study is to investigate the spatial and temporal structures of precipitation over the Korean Peninsula using extensive AWS (automatic weather stations) observation network data for the summertime from May to September. Additionally TRMM/PR precipitation data in the southern part of peninsula was used to investigate the vertical structure. For the spatial and temporal scales of hourly precipitation, the e-folding threshold approach was employed to cut off the correlation in terms of distance in km and time in hours. From a correlation analysis of AWS precipitation in terms of time and space, it was found out that the e-folding distance and e-folding time in correlation coefficients ranged from 50 km–110 km and 1 h–2 h. The shortest distance and time in e-folding values were found to be in July and August. Precipitation structures in May and September tended to be isotropic, a cell-type structure, and those of July and August had an apparent band type, from the southwest to northeast. In the case of the vertical feature of precipitation, the correlation with height showed that the vertically efficient height was within 5 km as convective rain cells with a monthly difference of 1.2 km. In this study, the coastal effect tended to slightly increase threshold values. 相似文献
16.
Ground-based measurements are essential for understanding alpine glacier dynamics,especially in remote regions where in-situ measurements are extremely limited.Prom 1 May to 22 July 2005(the spring-summer period),and from 2 October 2007 to 20 January 2008(the autumn-winter period),surface radiation as well as meteorological variables were measured over the accumulation zone on the East Rongbuk Glacier of Mt. Qomolangma/Everest at an elevation of 6560 m a.s.l.by using an automatic weather station(AWS).The... 相似文献
17.
Impact of precipitating ice on the simulation of a heavy rainfall event with advanced research WRF using two bulk microphysical schemes 总被引：1，自引：0，他引：1
G. A. Efstathiou N. M. Zoumakis D. Melas P. Kassomenos 《Asia-Pacific Journal of Atmospheric Sciences》2012,48(4):357-368
In this study, the Weather Research and Forecasting (WRF) model version 3.2 is used to examine the impact of precipitating ice and especially snow-graupel partitioning in the simulation of a heavy rainfall event over Chalkidiki peninsula in Northern Greece. This major precipitation event, associated with a case of cyclogenesis over the Aegean Sea, occurred on the 8th of October 2006 causing severe flooding and damage. Two widely used microphysical parameterizations, the Purdue Lin (PLIN) and WRF Single-Moment 6-class scheme (WSM6) are compared with available raingauge measurements over the complex topography of Chalkidiki. To further investigate the importance of snow and graupel relative mass content and the treatment of precipitating ice sedimentation velocity, two older versions of the WSM6 scheme were compiled and run with the current model. The verification results indicate that all simulations were found to match raingauge data more closely over the eastern mountainous Chalkidiki peninsula where maximum accumulations were observed. In other stations all schemes overestimate 24h accumulated rainfall except a station situated at the western part of the peninsula, where none of the simulations was able to reproduce observed rainfall. Graupel dominance in PLIN generates rapid precipitation fallout at the point of maximum predicted 24h accumulation. Similar behavior is shown in WSM6 from WRF version 2, but with significant less rainfall. Increasing snow amounts aloft, due to the unified treatment of precipitating ice in WSM6 from WRF version 3, modifies rain dynamics which decrease rainfall rates, but increases 24h accumulations. A sensitivity experiment where PLIN is used with snow accretion by graupel turned off, indicated that this process seems to be the most important factor controlling the differences in surface precipitation between PLIN and WSM6 from WRF version 3, determining the spatial and temporal distribution of this heavy precipitation event. The results also revealed that snow overestimation can lead to high rainfall accumulations, even though rain is more evenly distributed over the 24h period, deteriorating precipitation forecast. 相似文献
18.
Jung-Moon Yoo Young-In Won Young-Jun Cho Myeong-Jae Jeong Dong-Bin Shin Suk-Jo Lee Yu-Ri Lee Soo-Min Oh Soo-Jin Ban 《Asia-Pacific Journal of Atmospheric Sciences》2011,47(5):439-455
Various types of satellite (AIRS/AMSU, MODIS) and ground measurements are used to analyze temperature trends in the four vertical layers (skin/surface, mid-troposphere, and low stratosphere) around the Korean Peninsula (123–132°E, 33–44°N) during the period from September 2002 to August 2010. The ground-based observations include 72 Surface Meteorological Stations (SMSs), 6 radiosonde stations (RAOBs), 457 Automatic Weather Stations (AWSs) over the land, and 5 buoy stations over the ocean. A strong warming (0.052 K yr?1) at the surface, and a weak warming (0.004～0.010 K yr?1) in the mid-troposphere and low stratosphere have been found from satellite data, leading to an unstable atmospheric layer. The AIRS/AMSU warming trend over the ocean surface around the Korean Peninsula is about 2.5 times greater than that over the land surface. The ground measurements from both SMS and AWS over the land surface of South Korea also show a warming of 0.043～0.082 K yr?1, consistent with the satellite observations. The correlation average (r = 0.80) between MODIS skin temperature and ground measurement is significant. The correlations between AMSU and RAOB are very high (0.91～0.95) in the anomaly time series, calculated from the spatial averages of monthly mean temperature values. However, the warming found in the AMSU data is stronger than that from the RAOB at the surface. The opposite feature is present above the mid-troposphere, indicating that there is a systematic difference. Warming phenomena (0.012～0.078 K yr?1) are observed from all three data sets (SMS, AWS, MODIS), which have been corroborated by the coincident measurements at five ground stations. However, it should also be noted that the observed trends are subject to large uncertainty as the corresponding 95% confidence intervals tend to be larger than the observed signals due to large thermal variability and the relatively short periods of the satellitebased temperature records. The EOF analysis of monthly mean temperature anomalies indicates that the tropospheric temperature variability near Korea is primarily linked to the Arctic Oscillation (AO), and secondarily to ENSO (El Niño and Southern Oscillation). However, the low stratospheric temperature variability is mainly associated with Southern Oscillation and then additionally with Quasi-Biennial Oscillation (QBO). Uncertainties from the different spatial resolutions between satellite data are discussed in the trends. 相似文献
19.
The aim of the present study is to investigate the spatial and temporal structures of precipitation over the Korean Peninsula using extensive AWS (automatic weather stations) observation network data for the summertime from May to September. Additionally TRMM/PR precipitation data in the southern part of peninsula was used to investigate the vertical structure. For the spatial and temporal scales of hourly precipitation, the e-folding threshold approach was employed to cut off the correlation in terms of distance in km and time in hours. From a correlation analysis of AWS precipitation in terms of time and space, it was found out that the e-folding distance and e-folding time in correlation coefficients ranged from 50 km–110 km and 1 h–2 h. The shortest distance and time in e-folding values were found to be in July and August. Precipitation structures in May and September tended to be isotropic, a cell-type structure, and those of July and August had an apparent band type, from the southwest to northeast. In the case of the vertical feature of precipitation, the correlation with height showed that the vertically efficient height was within 5 km as convective rain cells with a monthly difference of 1.2 km. In this study, the coastal effect tended to slightly increase threshold values. 相似文献
20.
北京自动气象站实时数据质量控制应用 总被引：33，自引：5，他引：28
自动气象站(AWS)观测资料是中尺度、短时效天气预报不可缺少的重要资料源之一.但由于AWS观测资料的特殊性,其质量问题不同程度地阻碍了它的使用.因此,AWS观测资料的质量控制越显重要.北京市气象局设计的自动气象站观测数据质量控制的方案主要是物理极值检查、历史极值检查、内部一致性检查、时间一致性检查、空间一致性检查等方法并把它应用于北京地区2007年奥运气象服务演练,取得了令人鼓舞的效果.结果表明:该质量控制方案的建立,能够实时反映北京市气象局自动站观测数据的可靠性,同时也反映出数据的缺测和及时性也存在一些问题.此系统的运行对2008年奥运气象服务,特别是对INFO2008和城市运行实时数据服务的可靠性将会发挥重要作用. 相似文献