DZZ2型自动站监控软件数据故障分析与处理     

乔卫平  李计萍  纪春艳  原冬梅  李沁宁  张波 《山西气象》2010,(3):45-46

2010年4月8日16时至9日10时,霍州市气象局自动站出现故障,监控软件无法正常显示各气象要素实时数据,通过认真分析查找原因,逐步排查故障,最终使问题得以圆满解决。本文对该次故障现象与分析处理过程进行了总结。  相似文献   

Three-year Variations of Water, Energy and CO$_2$ Fluxes of Cropland and Degraded Grassland Surfaces in a Semi-arid Area of Northeastern China   总被引：1，自引：0，他引：1  

LIU Huizhi  TU Gang  FU Congbin  SHI Liqing 《大气科学进展》2008,25(6):1009-1020

Based on 3 years （2003-05） of the eddy covariance （EC） observations on degraded grassland and cropland surfaces in a semi-arid area of Tongyu （44°25′N, 122°52′E, 184 m a.s.1.）, Northeast China, seasonal and annual variations of water, energy and CO2 fluxes have been investigated. The soil moisture in the thin soil layer （at 0.05, 0.10 and 0.20 m） clearly indicates the pronounced annual wet-dry cycle; the annual cycle is divided into the wet （growing season） and dry seasons （non-growing season）. During the growing season （from May to September）, the sensible and latent heat fluxes showed a linear dependence on the global solar radiation. However, in the non-growing season, the latent heat flux was always less than 50 W m^-2, while the available energy was dissipated as sensible, rather than latent heat flux. During the growing season in 2003-05, the daily average sensible and latent heat fluxes were larger on the cropland surface than on the degraded grassland surface. The cropland ecosystem absorbed more CO2 than the degraded grassland ecosystem in the growing season in 2003-05. The total evapotranspiration on the cropland was more than the total precipitation, while the total evapotranspiration on the degraded grassland was almost the same as the total annual precipitation in the growing season. The soil moisture had a good correlation with the rainfall in the growing season. Precipitation in the growing season is an important factor on the water and carbon budget in the semi-arid area.  相似文献   

The Effects of Line-Wing Cutoff in LBL Integration on Radiation Calculations          下载免费PDF全文

ZHANG Hu  SHI Guangyu  LIU Yi 《Acta Meteorologica Sinica》2008,22(2):248-255

There are three basic methods in radiative transfer calculations, i.e., line-by-line (LBL) integration, correlated k-distribution method, and band model. The LBL integration is the most accurate of all, in which, there are two quadrature algorithms named in this paper as integration by lines and by sampling "points when calculating atmospheric transmittance in the considered wavenumber region. Because the LBL integration is the most expensive of all, it is necessary and important to save calculation time but increase calculation speed when it is put into use in the daily operation in atmospheric remote sensing and atmospheric sounding. A simplified LBL method is given in this paper on the basis of integration by lines, which increases computational speed greatly with keeping the same accuracy. Then, we discuss the effects of different cutoff schemes on atmospheric absorption coefficient, transmittance, and cooling rate under both of accurate and simplified LBL methods in detail. There are four cutoff schemes described in this paper, i.e., CUTOFFs 1, 2, 3, and 4. It is shown by this numerical study that the way to cut off spectral line-wing has a great effect on the accuracy and speed of radiative calculations. The relative errors of the calculated absorption coefficients for CUTOFF 2 are the largest under different pressures, while for CUTOFF 1, they are less than 2% at most of sampling points and for CUTOFFs 3 or 4, they are ahnost less than 5% in the calculated spectral region, however, the calculation time is reduced greatly. We find in this study that the transmittance in the lower atmosphere is not sensitive to different LBL methods and different cutoff schemes. Whereas for the higher atmosphere, the differences of transmittance results between CUTOFF 2 and each of other three cutoff schemes are the biggest of all no matter for the accurate LBL or for the simplified LBL integrations. By comparison, the best and optimized cutoff scheme is given in this paper finally.  相似文献   

Observations of Cloud Condensation Nuclei in North China          下载免费PDF全文

SHI Lixin  DUAN Ying 《Acta Meteorologica Sinica》2008,22(1):97-106

Using a DMT （Droplet Measurement Technologies） continuous flow streamwise thermal gradient cloud condensation nuclei （CCN） counter mounted on a Cheyenne IIIA aircraft, about 20 flights for aircraft mea- surements of CCN over North China were conducted in the autumn of 2005 and spring of 2006. According to the design for aircraft observation, the method of spiral ascent or descent in the troposphere was used for the vertical measurement of CCN, and some certain levels were chosen for horizontal measurement. The vertical distributions of CCN concentrations show that most CCN particles are concentrated in the low level of troposphere and CCN concentration decreased with height increasing. It suggests that the main source of CCN is from the surface. This result is consistent with former studies during 1983-1985 in China with a static thermal gradient CCN counter. The comparison of vertical observations between polluted rural area near Shijiazhuang and non-polluted rural area near Zhangjiakou shows that there is about five times difference in CCN concentration. But over two polluted cities, Shijiazhuang and Handan, there is no notable difference in CCN concentration. The horizontal flight measurements for penetrating the cumulus clouds experiment show the apparent decrease of CCN in clouds. It confirms that cloud has a definite consumptive effect on CCN particles because some CCN particles can form cloud droplets. The surface measurements of CCN in Shijiazhuang City were made during June-August 2005. The statistical CCN data show the great difference in concentration at the same supersaturation （S） in Shijiazhuang summertime. The minimum CCN concentrations were 584, 808, and 2431 cm-3, and the maximum concentrations were 9495, 16332, and 21812 cm-3 at S=0.1%, 0.3%, and 0.5%, respectively. CCN has a diurnal variation cycle. From 0600 BT, the concentration began to increase and reached the maximum at about noon. Then it generally decreased throughout the afternoon. The reason maybe is related to the onset o  相似文献   

Study of Methods for Three-Dimensional Multiple-Radar Reflectivity Mosaics          下载免费PDF全文

XIA Yanjiao  LIU Liping  SHI Yan 《Acta Meteorologica Sinica》2008,22(3)

This paper investigated several approaches to remapping and combining multiple-radar reflectivity fields onto a unified 3D Cartesian grid with high spatial and temporal resolutions,and analyzed systematic ob servation differences among multiple radars.The remapping approaches were evaluated by inspecting the spatial consistency of the reflectivity fields on vertical and horizontal cross sections on the equidistant line of radars,and the intensity change of 1-h accumulated precipitation before and after interpolation.The com bining approaches were evaluated by continuity examination.The results show that for remapping schemes,the vertical interpolation with nearest neighbor on the range-azimuth plane is the most reasonable scheme that provides consecutive reflectivity fields and retains the high-resolution structure comparable to that of the raw data;for multiple-radar data mosaics,the distance-exponential-weighted mean scheme provides spatially consistent reflectivity mosaics.The mosaics call mitigate various problems caused by the radar beam geometry such as the cone of silence.  相似文献   

商丘市1980-2009年飑线的发生与危害     

熊坤  陈巧  张艳玲  刘文新 《气象与环境科学》2010,33(Z1)

利用商丘站1980-2009年观测资料,分析了飑线的发生、发展规律及其危害.结果表明,近30 a来商丘几乎年年发生飑线天气,1年最多发生12次,每年夏季(6-8月)飑线活动最为频繁,每一次飑线天气都造成不同程度的人员伤亡和经济损失;20世纪80年代以后,飑线发生次数呈增长趋势.  相似文献   

郑州市两次不同背景下特大暴雨诊断分析   总被引：1，自引：1，他引：0  

宋清芝  乔春贵  谷秀杰  林丽 《气象与环境科学》2010,33(3):11-17

利用NCEP资料,根据降水实况分布及各物理量分层平面分布,每隔6 h对特大暴雨中心区所在经、纬向带各物理量场作经、纬向垂直剖面图,结合高空观测图对郑州市两次特大暴雨发生的大环流形势场、触发特大暴雨发生的各物理量场进行诊断分析。结果表明:1)连续性特大暴雨区出现在低空急流轴的前方,一方面是由于低空急流前方水平辐合较强,另一方面低空急流对暖湿空气的输送,使大气不稳定度加强;局地短时性特大暴雨过程主要是冷空气侵入使冷暖湿空气团在郑州上空交汇,其对流不稳定能量释放所致。2)辐合线对暖湿空气的抬升运动起到动力加强作用,是触发中尺度雨团的根源,也是特大暴雨产生的根源。3)连续性暴雨发生、发展时,高空的反气旋起主导作用;局地短时性暴雨发生时,中低空的气旋辐合起主导作用。4)短时性特大暴雨天气,前期有较强的不稳定层结;连续性暴雨天气刚发生时,其前期存在较强的不稳定层结,在暴雨连续发生过程中不一定有强不稳定层结。5)连续性暴雨需要较强的水汽输送带,局地短时性暴雨不要求有明显的水汽输送。  相似文献   

遥感图像融合方法研究   总被引：1，自引：0，他引：1  

乔玉良  尚彦玲  魏信 《气象与环境科学》2010,33(1):73-76

利用遥感图像专业处理软件ENVI与ERDAS IMAGINE,对珠海市2002年的Landsat 7 ETM+遥感数据进行了图像融合方法试验,包括IHS变换、Brovey变换、K-L变换和Gram Schmidt波谱锐化等。然后利用定性和定量方法对各种方法的融合结果进行了光谱特征和统计参数等方面的评价。研究结果表明:Gram Schmidt波谱锐化在纹理信息、亮度信息和光谱信息等方面都优于其他几种融合方法。  相似文献   

中国新一代极轨气象卫星——风云三号   总被引：18，自引：2，他引：16  

杨军  董超华  卢乃锰  杨忠东  施进明  张鹏  刘玉洁  蔡斌 《气象学报》2009,67(4):501-509

风云三号(简称FY-3)是中国第2代极地轨道气象卫星系列.它的第1颗星--风云三号A星(FY-3A)于2008年5月27日上午11时02分33秒在山西太原卫星发射中心发射升空.新一代极轨气象卫星主要是实现伞球、全天候、三维、定量、多光谱遥感,以满足现代气象业务,特别是数值天气预报业务的发展,同时监测大范围气象及其衍生自然灾害和生态环境变化,为研究全球气候变化规律,进行气候诊断和预测提供地球物理参数,为农、林、交通、海洋、水文等多领域提供服务.FY-3A携带11个对地观测仪器,其观测数据通过星地链路进入地面接收站,并在数据处理和服务中心(国家卫星气象中心大楼内)汇集.在强大的计算机和网络支撑下,利用科学算法对仪器遥感数据进行处理,生成各类产品,提供给用户使用.FY-3A发射后,经过半年的在轨测试和试运行,于2009年初正式投入业务运行,卫星和地面系统状态稳定,工作正常.文中较系统全面地介绍了卫星轨道、数传、仪器、数据接收、处理和产品等,尤其分析了星载仪器的主要技术特征,并给出了部分产品应用实例.  相似文献   

华南地区城市化对区域气候变化的影响   总被引：5，自引：2，他引：3  

吴婕  徐影  师宇 《气候与环境研究》2015,20(6):654-662

按照人口数将华南地区站点分为大城市站、一般城市站、郊区站,并利用华南地区1960~2011年的站点观测资料分别计算了3类站点年平均、季节平均的气温、高温日数、降水、相对湿度、风速、日照时数距平序列的变化,分析了城市化对华南地区区域气候的影响。结果表明:相较于背景场,大城市的平均气温有更明显的上升趋势;高温日数在3类站点中均有增加的趋势,在城市化的影响下,大城市的高温日数有明显的增加;平均气温日较差在整个华南地区均有下降趋势,特别是在大城市中。在3类站点中,降雨总量均有减少的趋势,且降雨更多的以中雨及以上的形式表现。该地区的相对湿度、风速、日照时数均呈现减少趋势,在城市化影响下,大城市的相对湿度、风速、日照时数均有明显的减少。华南地区处于我国最大的城市群之一——珠江三角洲地区,同时处于气候系统复杂的热带季风区,因此有必要研究城市化对该地区多个气象变量的可能影响。  相似文献