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1.
利用Nimbus-7行星反射率观测资料估算青藏高原地区的总辐射   总被引:10,自引:1,他引:10  
钟强  眭金娥 《气象学报》1989,47(2):165-172
本文利用1982年8月—1983年7月期间Nimbus-7行星反射率的月平均资料用“物理模式方法(Raschke and Preuss,1979)”估算了青藏高原及其邻近地区月平均地面总辐射的分布。得到的结果较好地反映了纬度、海拔与云量三个主要因子对总辐射分布的支配作用。根据高原及其邻近地区23个测站的资料,对总辐射的计算值与观测值进行了比较。统计分析表明,相关系数f=0.90,标准误差RMS=27w/m~2,平均绝对误差ABS=21w/m~2(相当于有效平均总辐射的11.7%)。文中还对误差来源和敏感性问题进行了讨论。  相似文献   

2.
临安与龙凤山辐射数据质量及初步结果比较   总被引:1,自引:1,他引:0       下载免费PDF全文
采用国际通用的辐射数据质量评估方法对2005—2011年浙江临安、黑龙江龙凤山两个区域大气本底站辐射观测资料进行质量评估与比较分析。结果表明:两站辐射数据通过物理可能限制检验与极端罕见限制检验的百分比均超过99.5%,但通过相关要素比较限制检验的百分比上,临安与龙凤山站分别降至97.9%与95.9%;双轴定位追踪太阳出现偏差是造成直接辐射与散射辐射数据精度降低的主要原因。CM21表的热偏移在-5 W·m-2以内,而其进行热偏移订正可以显著提高数据的通过率。对应同一太阳天顶角,临安站晴空总辐射与直接辐射均低于龙凤山站,散射辐射则相反,其原因是临安的大气透明系数较低,大气浑浊度较高。2006—2011年,临安站的大气向下长波辐射呈下降趋势,达到了0.01的显著性水平,且其多年平均值 (363.7±59.3 W·m-2) 显著高于龙凤山站 (274.9±77.6 W·m-2);龙凤山站晴空太阳总辐射呈增加趋势,达到了0.1的显著性水平。  相似文献   

3.
Solar Radiation Climatology of Alaska   总被引:1,自引:1,他引:0  
Summary There are only six locations in Alaska for which global radiation data of more than a year in duration are available. This is an extremely sparse coverage for a state which covers 1.5×10&6 km2 and stretches over at least three climatic zones. Cloud observations are, however, available from 18 stations. We used fractional cloud cover and cloud type data to model the global radiation and thus obtain a more complete radiation coverage for Alaska. This extended data set allowed an analysis of geographic and seasonal trends. A simple 1-layer model based on Haurwitz’s semi-empirical approach, allowing for changes in cloud type and fractional coverage, was developed. The model predicts the annual global radiation fluxes to within 2–11% of the observed values. Estimated monthly mean values gave an average accuracy within about 6% of the measurements. The estimates agree well with the observations during the first four months of the year but less so for the last four. Changing surface albedo might explain this deviation. Previously, the 1993 National Solar Radiation Data Base (NSRDB) from the National Renewable Energy Laboratory (NREL) modeled global radiation data for 16 Alaskan stations. Although more complete and complex, the NREL model requires a larger number of input parameters, which are not available for Alaska. Hence, we believe that our model, which is based on cloud-radiation relationship and is specifically tuned to Alaskan conditions, produces better results for this region. Annual global solar radiation flux measurements are compared with results from global coverage models based on the International Satellite Cloud Climatology Project (ISCCP) data. Contour plots of seasonal and mean annual spatial distribution of global radiation for Alaska are presented and discussed in the context of their climatic and geographic settings. Received July 16, 1997 Revised May 18,1998  相似文献   

4.
Abstract?This paper presents the results of measurements of the concentration of surface ozone and concurrent standard meteorological parameters: total solar radiation, temperature, relative humidity, pressure, wind speed, and vertical and horizontal components of the wind. The data were collected from 2005 to 2010 at stations located in central Poland (Mazowieckie voivodeship): Warszawa (urban), Legionowo (suburban), Granica and Belsk (rural). Furthermore, Granica is situated in the forested area of Kampinoski National Park. Continuously measured surface ozone concentrations demonstrated the well-known diurnal cycle of surface ozone concentration with a maximum in the afternoon and a minimum in the early morning hours. The averaged diurnal variations over six years reveal that the highest concentrations appear at rural stations (Belsk: 55?µg?m?3 and Granica: 50?µg?m?3) and the lowest at the urban station (Warszawa: 41?µg?m?3). The threshold for high levels of surface ozone (120?µg?m?3 per 8?h) was exceeded most often at Granica and Belsk. The occurrence of the ozone “weekend effect,” especially at urban stations, has been identified. The difference between weekend and weekday surface ozone concentrations at urban and rural stations was as high as 6.5?µg?m?3 and approximately 2?µg?m?3, respectively. Using appropriate statistical tools, it has been shown that meteorological conditions have a significant influence on ozone concentration. High correlation coefficients were found between ozone concentration and solar radiation, temperature, relative humidity, and wind speed. The forward stepwise regression model explains up to 75% of the variations in daily surface ozone concentration in terms of meteorological variability in summer and up to 70% in winter. At the same time, a multilayer perceptron neural network model was used to reconstruct the concentration of surface ozone. High correlation coefficients (up to 0.89) indicate that, on the basis of standard meteorological parameters and NO2 concentration, we can determine ozone concentration with high accuracy.  相似文献   

5.
This research examines the influence of cloud on the cataract effective UV (UVCat) irradiances on a horizontal plane over an extended period of 12months that included the range of cloud conditions, solar zenith angle (SZA) and ozone conditions experienced over that time. The data were collected at five minute intervals. Cloud modification factors were determined from the influence of clouds on the global broadband solar radiation and these were applied to the cloud free cataract effective UV to evaluate the UVCat irradiances on a horizontal plane for all cloud conditions. A comparison of the measured and calculated UVCat irradiances for the 2004 data set in the range of SZA of 70° or less provided an R2 value of 0.85. The data in the first 6months of 2005 for an SZA of 70° or less that were at a different time to that when the technique was developed provided an R2 value of 0.83 for the comparison of the measured and calculated UVCat irradiances.  相似文献   

6.
The characteristics of net radiation (Rn)(0.3--10 μm) in Lhasa and Haibei in the Tibetan Plateau were analyzed based on long-term in-situ measurements of surface radiation data. The monthly average of daily Rn reached a minimum during the winter period followed by an increase until May and then a decline until January. This variation is consistent with solar activity. The annual mean daily total Rn values were 0.92 MJ m-2 d-1 and 0.66 MJ m-2d-1 in Lhasa and Haibei, respectively. A relationship between Rn and broadband solar radiation (Rs) was demonstrated by a good linear correlation at the two sites. Rn can be an accurate estimate from Rs. The estimated Rn values were similar to the observed values, and the relative deviations between the estimates and measurements of Rn were 2.8% and 3.8% in Lhasa and Haibei, respectively. The application of the Rn estimating model to other locations showed that it could provide acceptable estimated Rn values from the Rs data. Furthermore, we analyzed the influence of clouds on Rn by different clear index (Ks), defined as the ratio of Rs to the extraterrestrial solar irradiance on a horizontal surface. The results indicate that more accurate results are associated with increased cloudy conditions. The influence of the albedo was also considered, but its inclusion in the model resulted in only a slight improvement. Because surface albedo is not usually measured, an expression based solely on global solar radiation could be of more extensive use.  相似文献   

7.
Long-term,ground-based daily global solar radiation (DGSR) at Zhongshan Station in Antarctica can quantitatively reveal the basic characteristics of Earth’s surface radiation balance and validate satellite data for the Antarctic region.The fixed station was established in 1989,and conventional radiation observations started much later in 2008.In this study,a random forest (RF) model for estimating DGSR is developed using ground meteorological observation data,and a highprecision,long-term DGSR dataset is constructed.Then,the trend of DGSR from 1990 to 2019 at Zhongshan Station,Antarctica is analyzed.The RF model,which performs better than other models,shows a desirable performance of DGSR hindcast estimation with an R~2 of 0.984,root-mean-square error of 1.377 MJ m~(-2),and mean absolute error of 0.828 MJ m~(-2).The trend of DGSR annual anomalies increases during 1990–2004 and then begins to decrease after 2004.Note that the maximum value of annual anomalies occurs during approximately 2004/05 and is mainly related to the days with precipitation (especially those related to good weather during the polar day period) at this station.In addition to clouds and water vapor,bad weather conditions (such as snowfall,which can result in low visibility and then decreased sunshine duration and solar radiation) are the other major factors affecting solar radiation at this station.The high-precision,longterm estimated DGSR dataset enables further study and understanding of the role of Antarctica in global climate change and the interactions between snow,ice,and atmosphere.  相似文献   

8.
山东禹城紫外辐射变化特征及其估测方程的建立   总被引:1,自引:0,他引:1  
刘慧  胡波  王跃思  王式功 《大气科学》2015,39(3):503-512
本文对2005~2011年山东禹城地区观测得到的紫外辐射的时间变化特征及紫外辐射与总辐射比值的变化特征进行了分析, 并结合气温、降水和露点温度资料建立了禹城地区的紫外辐射估测方程。结果表明:紫外辐射日累计值的变化范围为0.10~1.20 MJ m-2 d-1, 年平均值为0.468 MJ m-2 d-1;紫外辐射日、季节变化规律与总辐射一致, 季节变化都表现为冬季小夏季大, 最小值出现在1月, 最大值出现在6月, 日变化则呈现早晚小中午大的特征;紫外辐射与总辐射的比值范围为0.023~0.046, 其季节变化特征也是冬季小夏季大, 该比值随晴空指数的增大而减小, 而在晴空指数大于0.5时比较稳定。利用温度日较差(日最高气温与最低气温的差值)建立了紫外辐射估测方程, 决定系数R2达0.80, 平均相对误差为0.19, 估测紫外线等级与实测紫外线等级相差不大于1的数据占95%, 该方法可以较好地进行紫外辐射等级的估测。  相似文献   

9.
基于我国100个地面站点的地面太阳总辐射、日平均云量资料分析1961~2009年我国地面太阳辐射(Surface Solar Radiation,SSR)变化特征及云在不同时期对SSR的影响。结果显示:1961~2009年我国SSR经历了先下降后上升的变化过程,其中1961~1990年SSR显著下降("变暗"),下降速率为-4.3%/10 a(7.87 W m–2(10 a)–1),各地SSR变化趋势比较一致;1990年后SSR开始上升("变亮"),上升速率为2.8%/10 a(2.4 W m–2(10 a)–1),各地SSR变化趋势不如前一阶段一致,但没有显著的地域分布特征。晴空条件的设置对1961~1990年各站点SSR变化特征影响不大,仍为大范围下降("变暗"),但对1990~2009年的结果影响显著。相比全天空条件的结果,晴空条件下1990~2009年我国SSR变化有明显的南北特征,南方地区以"变亮"为主,而北方地区大多继续"变暗",但"变暗"速度减缓。1961~1990年我国总云量总体呈小幅下降趋势,下降速率很慢,这一时期总云量与全天空SSR没有很好的对应关系;1990~2009年我国总云量总体呈小幅上升趋势,有显著的南北分布差异,北方地区以上升趋势为主,南方地区以下降趋势为主,期间云量与全天空情况下SSR有很好的对应关系。这些结果表明,在"变暗"阶段,云对SSR的作用不显著,而在"变亮"阶段,云的作用变得较为突出。  相似文献   

10.
鼎湖山森林地区臭氧及其前体物的变化特征和分析   总被引:18,自引:2,他引:16  
通过对鼎湖山森林地区近地面O3和NOx浓度、太阳辐射、气象参数等为期一年的观测和资料分析,给出了地面O3和NOx浓度、太阳辐射的变化规律及其相互之间的关系.地面O3、NOx、CO、SO2浓度以及紫外辐射、太阳总辐射等有明显的日变化和季节变化.不同因子对O3的敏感性试验结果表明,晴天和实际天气,O3浓度对NO、NO2浓度的变化最为敏感,其次是水汽、气溶胶,最后是紫外辐射.所有因子的变化均引起O3在湿季比干季更大的变化率,因此在研究臭氧化学和光化学时,应该考虑水汽以及OH自由基的重要作用.对于晴天和实际天气的逐时值和日平均值而言,O3浓度与NO2/NO之间存在很好的正相关关系,比值NO2/NO可以作为判断O3峰值出现的一个指标.O3极值的出现既受NO和NOx影响,也受气象因素(温湿度、云、风、雾、降雨)和辐射的影响.周末O3、NOx浓度及NO2/NO有规律的增大,表明实验地点的大气受到人为污染源的影响.  相似文献   

11.
Summary The diurnal variation of the Earth Radiation Budget and its components require for sparsely temporal sampling a high amount of modeling for the derivation of precise daily averages. In the present study the time integration errors of the regional monthly averages of the Earth Radiation Budget Experiment (Barkstrom, 1984) are estimated for April 1985. For this error assessment we made use of data of the European geostationary satellite Meteosat 2 which narrowbanded measurements have been converted to reasonable estimates of broad-band radiation fluxes. Based on this data set the measurements of the ERBE satellites, ERBS, NOAA 9, and NOAA 10 are simulated. For the time integration the ERBE time integration models are used.The mean error for the regional monthly average of the net radiation flux varies between — 3 and + 5 W/m2 for the combination of all three satellites. The largest contribution to this uncertainty is given by the time integration of the shortwave fluxes. A new approach for the time integration procedure is presented which is based on the Maximum Entropy spectral analysis of temporal high resolution data sets as provided by geostationary satellites.This study closes with the estimation of the final error for ERBE regional monthly averages of the net radiation flux, which includes the uncertainties of the instruments, the inversion process and the time integration process. These errors lie between 11.1 W/m2 for single NOAA 9 products and 7.8 W/m2 for the combination of all three satellites. With that the Earth Radiation Budget Experiment fulfills the required accuracy.With 12 Figures  相似文献   

12.
环渤海地区1961—2010年太阳总辐射时空变化特征   总被引:1,自引:0,他引:1  
根据1961—2010年环渤海地区4个辐射站太阳总辐射资料和56个台站日照百分率资料,研究了该地区太阳总辐射的时空分布及变化特征。同时利用1991—2010年太阳总辐射数据初步分析了环渤海地区太阳能资源潜力。结果表明:年内太阳辐射呈单峰型,5月最高,4—8月是太阳能资源最丰富的时期;1961—2010年太阳总辐射在1990年之前呈显著下降,之后没有明显变化趋势;太阳总辐射趋势变化在环渤海地区有明显的空间差异,下降幅度最大的集中于京津塘周边地区以及山东中南部地区;四季总辐射均呈显著下降趋势,其中春、夏两季降幅略高,秋、冬两季降幅略低;1991—2010年环渤海地区太阳总辐射呈西北部高,向东、南方向递减的分布特征。  相似文献   

13.
北京不同区域气溶胶辐射效应   总被引:1,自引:0,他引:1       下载免费PDF全文
采用大气辐射传输模式SES2以及2013年1月—2015年10月欧洲中期天气预报中心细网格再分析资料计算了北京地区4个观测站地面接收的短波辐射通量,分析了晴天和云天北京城郊气溶胶对总辐射的定量影响时空变化特征。结果表明:北京城区和近郊区气溶胶对总辐射的影响约为远郊区的2倍,北京南部和西部气溶胶对辐射的影响较大,晴天和云天北京城区和近郊区气溶胶对总辐射的削减值分别为146.23~180.99 W·m-2和202.11~217.02 W·m-2,晴天总辐射削减空间差异较大;秋冬季气溶胶对总辐射的影响明显大于春夏季,北京市观象台秋冬季气溶胶对总辐射的削减作用最大可达60%,较春夏季高10%~20%;北京城郊总辐射和直接辐射削减率与气溶胶光学厚度变化均呈线性关系,近地面PM2.5浓度对辐射的影响不容忽视。  相似文献   

14.
通过446183条全球晴空大气廓线的红外辐射传输模拟和统计回归,建立了由Himawari08成像仪通道遥测数据估算晴空地表上行、下行长波辐射通量的反演模式,模式应用于成像仪观测资料,处理出晴空地表上行、下行长波辐射通量实时产品,2016年2~6月的产品精度验证试验结果为:与相同时刻的AQUA卫星CERES仪器同类产品相比,地表上行通量均方根误差Re=7.9 W/m2,相关系数R=0.9399,地表下行通量Re=14.5 W/m2,R=0.9586;与由中国地面气象站地面气温和相对湿度观测经Brunt、Brutsaert经验公式计算的实时地表下行长波辐射通量相比,Re=15.34 W/m2,R=0.8786;与用陆表温度计算的地表上行长波辐射通量相比,Re=12.6 W/m2,R=0.9977。研究了2016年2、6月的晴空地表长波辐射产品,发现陆地晴空上、下行通量有着与太阳加热地表增温相应的明显日变化特征,峰值出现在12:00(当地时间,下同)至14:00,低谷出现在04:00至07:00,下行通量与上行通量几乎同步变化或约有延时,陆地上2个通量归一化的日变化指数类似一个半正弦曲线,而海面长波辐射通量则没有明显的日变化规律。  相似文献   

15.
We have developed a method for estimating hourly global solar radiation (GSR) from hourly sunshine duration data. This procedure requires only hourly sunshine duration as the input data and utilizes hourly precipitation and daily snow cover as auxiliary data to classify time intervals into six cases according to weather conditions. To obtain hourly GSR using a simple algebraic form, a quadratic function of the solar elevation angle and the sunshine duration ratio is used. Daily GSR is given by a sum of hourly GSRs. We evaluated the performance of the newly developed method using data obtained at 67 meteorological stations and found that the estimated GSR is highly consistent with that observed. Hourly and daily root-mean-square misfits are approximately 0.2 MJ/m2/h (~55 W/m2) and 1.4 to 1.5 MJ/m2/day (~16 to 17 W/m2), respectively. Our classification of weather conditions is effective for reducing estimation errors, especially under cloudy skies. Since the sunshine duration is observed at more meteorological stations than GSR, the proposed new method is a powerful tool for obtaining solar radiation with hourly resolution and a dense geographical distribution. One of the proposed methods, GSRgrn, can be applicable to hourly GSR estimations at different observation sites by setting local parameters (the precipitable water, surface albedo, and atmospheric turbidity) suitable to the sites. The hourly GSR can be applied for various micrometeorological studies, such as the heat budget of crop fields.  相似文献   

16.
1961-2007年云南太阳总辐射时空变化特征   总被引:9,自引:1,他引:8       下载免费PDF全文
根据云南省7个辐射站太阳总辐射资料和113个台站日照百分率资料,建立了1961-2007年全省太阳总辐射时间序列,运用旋转主分量方法将全省分为4个区,并在此基础上研究云南太阳总辐射的时空分布和变化特征。结果表明:云南太阳总辐射呈中部多,西南部次之,东部及西北部少的分布特征。1961-2007年呈波段减少的变化趋势,线性倾向率为-0.64%/10a,其中中部及东部显著减少,西南部略有增加。其间出现两次突变,一次是1986年的显著减少,另一次是1993年以后的回升。分析表明,相对湿度和云量是影响太阳总辐射变化的主要气象因子。  相似文献   

17.
NASA/GEWEX (National Aeronautics and Space Administration/Global Energy and Water Cycle Experiment) Surface Radiation Budget (SRB) has released its latest radiation dataset, version 3.0. We examine the accuracy of the monthly mean global radiation in China using surface-observed radiation (SOR) data at 42 stations during the period 1984?C2004. Overall comparison shows a general overestimation of satellite retrieval radiation data with a bias of 14.6?W?m?2 and a root mean square error of 25.9?W?m?2. Differences at individual stations suggested satellite data are consistently higher than surface measurements over eastern China (110°E), but occasional underestimation occurs in Western China, especially Southwest China. Intra-annual variation analysis indicates that SRB satellite radiation can capture the annual cycle well. For trend of global radiations, there are evident discrepancies between satellite retrievals and surface measurements for both the entire period and segmental terms. For the entire period from 1984 to 2004, most stations show a positive trend based on surface measurements, while the majority of collocated pixels show a negative trend. Segmental trends demonstrated that the principal difference occurred during the first period of 1981?C1994. After 1994, the two datasets change similarly. Therefore, trend analysis in terms of detecting global dimming/brightening remains very difficult as surface measurements and satellite products do not agree yet. In addition, some proposals are made towards better understanding of the bias of satellite products and to improve further the satellite retrieval algorithm with better representation of both cloud and aerosol properties.  相似文献   

18.
长波区间太阳辐射对气候模拟的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
长波区间的太阳辐射在气候模式中往往被忽略。利用国家气候中心BCC_AGCM2.0.1大气环流模式,采用矩阵算子辐射传输算法,研究了长波区间太阳辐射对气候模式辐射通量和温度模拟结果的影响。结果表明,以ISCCP和CERES辐射资料为标准,考虑长波区间太阳辐射后,长波区间晴空大气地表向下辐射通量平均误差减小2.05 W/m2,均方根误差减少1.29 W/m2;长波区间晴空大气模式顶向上辐射通量平均误差减小0.70 W/m2,均方根误差减小0.21 W/m2;长波区间有云大气地表向下辐射通量平均误差减小1.38 W/m2,均方根误差减小1.03 W/m2;长波区间有云大气模式顶向上辐射通量平均误差减小0.99 W/m2,均方根误差减小0.30 W/m2。以ECMWF再分析资料为标准,考虑长波区间太阳辐射后,赤道地区上对流层—下平流层区域温度的冷偏差得到改善,对流层顶温度平均误差减小0.27 K,均方根误差减小0.25 K。  相似文献   

19.
Ensembles of simulations of the twentieth- and twentyfirst-century climate, performed with 20 coupled models for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment, provide the basis for an evaluation of the Arctic (70°–90°N) surface energy budget. While the various observational sources used for validation contain differences among themselves, some model biases and across-model differences emerge. For all energy budget components in the twentieth-century simulations (the 20C3M simulation), the across-model variance and the differences from observational estimates are largest in the marginal ice zone (Barents, Kara, Chukchi Seas). Both downward and upward longwave radiation at the surface are underestimated in winter by many models, and the ensenmble mean annual net surface energy loss by longwave radiation is 35 W/m2, which is less than for the NCEP and ERA40 reanalyses but in line with some of the satellite estimates. Incoming solar radiation is overestimated by the models in spring and underestimated in summer and autumn. The ensemble mean annual net surface energy gain by shortwave radiation is 39 W/m2, which is slightly less than for the observational based estimates, In the twentyfirst-century simulations driven by the SRES A2 scenario, increased concentrations of greenhouse gasses increase (average for 2080–2100 minus average for 1980–2000 averages) the annual average ensemble mean downward longwave radiation by 30.1 W/m2. This was partly counteracted by a 10.7 W/m2 reduction in downward shortwave radiation. Enhanced sea ice melt and increased surface temperatures increase the annual surface upward longwave radiation by 27.1 W/m2 and reduce the upward shortwave radiation by 13.2 W/m2, giving an annual net (shortwave plus longwave) surface radiation increase of 5.8 W/m2 , with the maximum changes in summer. The increase in net surface radiation is largely offset by an increased energy loss of 4.4 W/m2 by the turbulent fluxes.  相似文献   

20.
This paper describes and tests two models for estimating net radiation(or the radiation balance)on sloping surfacesof alpine environments.They are an empirical method based on the linear relationship between net radiation and globalsolar radiation and a flux-by-flux method involving the estimation of all the individual components of radiation budgetindependently.The results show that the empirical method is capable of predicting hourly net radiation on sloping sur-faces to within about±53 W m~(-2) under all sky conditions.During clear sky conditions,it could predict net radiation onslopes to within±58 W m~(-2) or 16% of the measured values.The flux-by-flux method,although it did not perform aswell as the empirical method,performed adequately and could give estimates of net radiation on slopes with root meansquare error of less than 74 W m~(-2)(20%)and a mean bias error of 27 W m~(-2)(7%).  相似文献   

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