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1.
基于梅县区附近汕头气象站1986—2015年历年各月太阳总辐射和日照时数观测资料,采用最小二乘法建立了梅县站各月太阳总辐射与日照时数的关系方程。用梅县区日照时数观测资料,计算出梅县区1986—2015年太阳总辐射。采用线性趋势法和资源丰富程度、稳定程度等指标,对梅县区近30年的太阳能资源进行了分析和评估。结果表明,梅县区属太阳能资源丰富区,平均年太阳总辐射为4 467.08 MJ/m~2,年最小值为4 159.74 MJ/m~2,年最大值为4 834.0 MJ/m~2,总体呈增加趋势,增加速率为每年1.32 MJ/m~2。夏季辐射丰富,冬季偏少,夏季总辐射量是冬季的1.87倍,月平均总辐射7月最多(502 MJ/m~2),2月最少(268 MJ/m~2)。太阳能资源较稳定,月最大日照时数(7月)大于6 h的天数为21 d,是月最小(3月)日照时数的3倍,2—4月不利于太阳能利用。 相似文献
2.
两种不同初始场对太阳辐射模拟效果的影响 总被引：1，自引：0，他引：1
利用2010年1,4,7和10月ECMWF和NCEP再分析资料作为初始场和边界条件,应用辐射模式系统WRF-SES2模拟了北京观象台的总辐射、散射辐射和直接辐射,并与观测值进行对比,重点分析了模式初始场云量差异对辐射模拟的影响。结果表明:(1)1,4,7和10月多数时段总辐射模拟值较观测值偏大,散射辐射模拟值较观测值偏小,总云量模拟值小于观测值,直接辐射误差分布范围较总辐射、散射辐射大。(2)多数时段采用ECMWF再分析资料作为初边值条件模拟(简称EC方案)的总辐射、直接辐射、散射辐射误差小于NCEP资料作为初边值条件模拟(简称NCEP方案)的误差,即EC方案模拟太阳短波辐射效果优于NCEP方案,这可能与ECMWF再分析资料中的云微物理量误差相对较小有关。(3)1月和4月总辐射模拟效果较好,平均绝对误差最小,其中1月两种方案误差分布范围最小,且介于-50~200 W·m-2之间,10月次之,7月稍差;1,4月和10月两种方案模拟误差较接近,而7月EC方案模拟的总辐射误差小于NCEP方案。(4)1月直接辐射模拟效果较好,4月和10月次之,7月稍差;除4月外,其他3个月EC方案模拟的直接辐射误差小于NCEP方案。(5)1月和10月散射辐射模拟效果较好,4月和7月稍差;4个月EC方案模拟的散射辐射误差小于NCEP方案。(6)EC和NCEP方案对总辐射、直接辐射和散射辐射的模拟准确率受初始场中云量模拟效果的影响较大,当总云量模拟误差较小时,总辐射的模拟误差亦相对较小。(7)在多云和有降水天气过程时,EC和NCEP方案模拟的太阳辐射误差较大,需要通过资料同化方法改进模式初始场,并对模拟结果做进一步订正。 相似文献
3.
青藏高原北部及其邻近地区太阳加热率和大气红外冷却率 总被引：1，自引：1，他引：1
利用中分辨率辐射计算模式(MODTRAN3)和青藏高原北部及其邻近地区格尔木、哈密、酒泉三站的探空资料，对各站点夏季太阳直接辐射、向下总辐射和净辐射进行了计算，并进一步计算了大气的太阳加热率和红外冷却率。分析了青藏高原北部及其邻近地区的加热率和冷却率的一些特点。结果表明，青藏高原北部及其邻近地区加热率在llkm高度附近有最小值，夏季红外冷却率在llkm高度附近取得最大值，太阳天顶角的变化对太阳加热率有较强的影响。 相似文献
4.
利用2017年9月1日—2018年8月31日都江堰紫外辐射(UV-AB)的观测数据,分析了都江堰紫外辐射的变化特征及其与气象要素的相关性,并通过多元回归分析建立了都江堰紫外辐射辐照度预报方程。结果表明:都江堰的紫外辐照度具有明显的日变化、月变化、季节变化特征,辐照度主要受云、水汽和太阳高度角等的影响。全年最大日平均辐照度为55.84 W/m~2,最小日平均辐照度为2.39 W/m~2。全年10—15时平均紫外辐照度与14时总云量、10—15时最低相对湿度、10—15时最高气温分别呈负相关、负相关、正相关,相关系数分别为-0.60、-0.67、0.63。春、夏、秋、冬季的10—15时平均紫外辐照度预报方程均通过显著性水平α=0.05的F检验,调整后的R~2分别为0.84、0.78、0.82、0.78。方程平均偏差为2.61～5.02 W/m~2,标准误差为3.24～6.57 W/m~2。秋季预测值准确度最高,夏季最低。 相似文献
5.
香河地区光合有效辐射观测分析研究 总被引：3，自引：0，他引：3
利用中国科学院大气物理研究所香河大气综合观测实验站(39°47′N,116°57′E)2004年10月至2005年12月共15个月的太阳辐射观测资料,分析了该地区光合有效辐射与太阳总辐射比值的(PAR/Rs)日变化和季节变化特征,得出月平均PAR/Rs值变化范围在1.808~2.048μE.J-1之间,最大值出现在夏季,最小值出现在冬季,年平均值为1.948μE.J-1。提出了一个利用太阳总辐射观测值计算光合有效辐射瞬时值的参数化算式,用该算式计算得到的PAR与实际观测值的均方根误差为19.28μE.m-2.s-1,有96%的计算值与观测值偏差在±10%以内。比较了香河地区与太湖地区、额济纳地区光合有效辐射瞬时最大值、小时累积最大值及日累积最大值的差异。 相似文献
6.
FY-3B卫星VIRR仪器的向外长波辐射(outgoing long-wave radiation,OLR)产品处理采用与NOAA/AVHRR相同的算法模型,即用窗区通道亮温-通量等效亮度温度的回归关系式计算OLR,但两星的OLR业务产品与目前国际质量最好的云和地球辐射能量系统(cloud and earth’s radiant energy system,CERES)仪器观测OLR产品相比,存在约10 W·m~(-2)的系统负偏差。FY-3B的原因在于OLR反演模式建立过程中红外辐射传输计算软件的精度不够。鉴于此,本文采用美国21世纪开发的逐线辐射传输模型计算软件(LBLRTM),模拟计算了全球2521条大气廓线的大气顶辐射率光谱,在此基础上计算了每条廓线的OLR和FY-3B/VIRR窗区通道亮温,应用最小二乘法统计回归模拟数据,重新建立了由FY-3B/VIRR窗区通道亮温计算OLR的回归关系式及系数。模式应用于FY-3BL1级数据,处理2016年1,3,7和10月的FY-3B逐日全球OLR资料,该资料与AQUA-TERRA卫星的CERES仪器OLR观测产品相比,得到日平均OLR:RMSE=9~15 W·m~(-2),R=0.9834,Bias=-0.3W·m~(-2);月平均OLR:RMSE=4~7W·m~(-2),R=0.9915,Bias=-0.3W·m~(-2),表明改进的模式能处理出无系统偏差的、精度基本与CERES观测相当的OLR产品,尽管单通道反演算法有着固有的模式回归误差。 相似文献
7.
射出长波辐射(OLR)是大气科学研究领域的关键参量,并在辐射相互作用、气候变化和灾害监测等方面发挥重要作用。2018年6月5日静止气象卫星FY2H成功发射,OLR产品是FY2H的业务产品之一。在原有FY2系列OLR反演算法基础上,参考国际上NOAA/HIRS OLR反演算法,结合FY2H/VISSR 3个红外通道设置,建立适合FY2H的OLR反演算法。利用该算法处理FY2H/VISSR的L1级观测数据,生成实时及日、旬、月平均的OLR产品。FY2H的OLR产品与CERES均匀性下垫面的瞬时视场OLR产品对比,RMSE=3.38 W/m~2,R=0.99,Bias=0.77 W/m~2;与CDR日平均OLR产品对比,RMSE为5～7 W/m~2,R为0.97～0.98,Bias为-2.2～1.9 W/m~2;与CDR旬平均OLR产品对比,RMSE为3～5 W/m~2,R=0.99,Bias为-1.1～0.4 W/m~2;与CDR月平均OLR产品对比,RMSE为2～4 W/m~2,R=0.99,Bias为-1.1～0.4 W/m~2。这表明FY2H OLR改进算法达到了较高的精度,可满足卫星设计和应用研究精度需求。 相似文献
8.
本文对1987年5月在西沙永兴岛观测的Cl~-核与SO_4~-核资料进行了分析。主要结果是:(1)干直径大于2μ的Cl~-核平均浓度618个/L,平均含盐量57.2μg/m~3,介于普陀与海洋岛的观测值之间,谱型呈准单调下降的幂函数递减谱;最大干直径59μ的SO_4~-核平均浓度15个/L,平均含盐量23.8μg/m~3,谱较Cl~-核谱宽得多。(2)Cl~-核与SO_4~-核浓度均随离海面高度增加而减少。(3)盐核分布与风速,波高有较好的对应关系;Cl~-核在14时出现极大值,其日变化规律与潮位有一定关系。 相似文献
9.
利用塔克拉玛干沙漠塔中大气环境观测试验站2007年1月至201 1年12月总辐射、散射辐射和直接辐射观测资料,分析了塔克拉玛干沙漠腹地太阳总辐射、散射辐射和水平面直接辐射的主要特征。结果表明:塔克拉玛干沙漠腹地总辐射、散射辐射和水平面直接辐射平均年总量分别为6619.0、3507.8和2203.5 MJ·m~(-2)。典型晴天总辐射日峰值分别为散射辐射的2.4倍和直接辐射的1.5倍。沙尘暴天散射辐射值增加到与总辐射基本一致,而直接辐射衰减最明显。当太阳高度角20°时,散射辐射随总云量的增加而增大,且秋、冬两季增幅明显。 相似文献
10.
本文论述了用机载MSS(多光谱扫描仪)资料评价小区域地表面热量平衡分布的方法及其应用结果。通过分析在日本茨城县南部秋季白天测得的资料,得到了如下结果:(1)在分析的对象区域,地表面平均温度为19.1℃,与以此平均值为基准的温度差,水面为-11.6℃,森林为-6.0℃,草地+0.5℃,混凝土+3.4℃,沥青+3.8℃,裸地+3.9℃,施肥地+4.8℃。(2)计算得出的分析对象区域净辐射通量平均密度为398W/m~2,若以此值为100,则可求出水面的净辐射通量密度为135,森林为121,草地104,裸地96,沥青95,混凝土77,施肥地68。(3)计算得出的分析对象区域感热通量的平均密度为91W/m~2,若以此值为100,则可求出水面感热通量密度为-31,森林为-8,草地115,裸地146,施肥地154,混凝土237,沥青268。(4)计算得出的分析对象区域潜热通量平均密度为244W/m~2,若以此值为100,则可求出水面与森林的潜热通量密度为183,草地为109,裸地71,施肥地31。 相似文献
11.
In this study,the clear sky hourly global and net solar irradiances at the surface determined using SUNFLUX,a simple parameterization scheme,for three stations(Gaize,Naqu,and Lhasa) on the Tibetan Plateau were evaluated against observation data.Our modeled results agree well with observations.The correlation coefficients between modeled and observed values were > 0.99 for all three stations.The relative error of modeled results,in average was < 7%,and the root-mean-square variance was < 27 W m 2.The solar irradiances in the radiation model were slightly overestimated compared with observation data;there were at least two likely causes.First,the radiative effects of aerosols were not included in the radiation model.Second,solar irradiances determined by thermopile pyranometers include a thermal offset error that causes solar radiation to be slightly underestimated.The solar radiation absorbed by the ozone and water vapor was estimated.The results show that monthly mean solar radiation absorbed by the ozone is < 2% of the global solar radiation(< 14 W m 2).Solar radiation absorbed by water vapor is stronger in summer than in winter.The maximum amount of monthly mean solar radiation absorbed by water vapor can be up to 13% of the global solar radiation(95 W m 2).This indicates that water vapor measurements with high precision are very important for precise determination of solar radiation. 相似文献
12.
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
13.
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
14.
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
15.
Asgeir Sorteberg Vladimir Kattsov John E. Walsh Tatyana Pavlova 《Climate Dynamics》2007,29(2-3):131-156
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
16.
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
17.
从Himawari08卫星估算晴空地表长波辐射及其日变化特征初探 总被引：1，自引：0，他引：1
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
18.
The atmospheric energy budget and implications for surface fluxes and ocean heat transports 总被引：2，自引：4，他引：2
Comprehensive diagnostic comparisons and evaluations have been carried out with the National Centers for Environmental Prediction/National
Center for Atmospheric Research (NCEP/NCAR) and European Centre for Medium Range Weather Forecasts (ECMWF) reanalyses of the
vertically integrated atmospheric energy budgets. For 1979 to 1993 the focus is on the monthly means of the divergence of
the atmospheric energy transports. For February 1985 to April 1989, when there are reliable top-of-the-atmosphere (TOA) radiation
data from the Earth Radiation Budget Experiment (ERBE), the implied monthly mean surface fluxes are derived and compared with
those from the assimilating models and from the Comprehensive Ocean Atmosphere Data Set (COADS), both locally and zonally
integrated, to deduce the implied ocean meridional heat transports.
While broadscale aspects and some details of both the divergence of atmospheric energy and the surface flux climatological
means are reproducible, especially in the zonal means, differences are also readily apparent. Systematic differences are typically
∼20 W m−2. The evaluation highlights the poor results over land. Land imbalances indicate local errors in the divergence of the atmospheric
energy transports for monthly means on scales of 500 km (T31) of 30 W m−2 in both reanalyses and ∼50 W m−2 in areas of high topography and over Antarctica for NCEP/NCAR. Over the oceans in the extratropics, the monthly mean anomaly
time series of the vertically integrated total energy divergence from the two reanalyses correspond reasonably well, with
correlations exceeding 0.7. A common monthly mean climate signal of about 40 W m−2 is inferred along with local errors of 25 to 30 W m−2 in most extratropical regions. Except for large scales, there is no useful common signal in the tropics, and reproducibility
is especially poor in regions of active convection and where stratocumulus prevails. Although time series of monthly anomalies
of surface bulk fluxes from the two models and COADS agree very well over the northern extratropical oceans, the total fields
all contain large systematic biases which make them unsuitable for determining ocean heat transports. TOA biases in absorbed
shortwave, outgoing longwave and net radiation from both reanalysis models are substantial (>20 W m−2 in the tropics) and indicate that clouds are a primary source of problems in the model fluxes, both at the surface and the
TOA. Time series of monthly COADS surface fluxes are shown to be unreliable south of about 20∘N where there are fewer than 25 observations per 5∘ square per month. Only the derived surface fluxes give reasonable implied meridional ocean heat transports.
Received: 21 March 2000 / Accepted: 21 June 2000 相似文献
19.
The air–sea fluxes of momentum, heat, freshwater and their components have been computed globally from 1948 at frequencies ranging from 6-hourly to monthly. All fluxes are computed over the 23 years from 1984 to 2006, but radiation prior to 1984 and precipitation before 1979 are given only as climatological mean annual cycles. The input data are based on NCEP reanalysis only for the near surface vector wind, temperature, specific humidity and density, and on a variety of satellite based radiation, sea surface temperature, sea-ice concentration and precipitation products. Some of these data are adjusted to agree in the mean with a variety of more reliable satellite and in situ measurements, that themselves are either too short a duration, or too regional in coverage. The major adjustments are a general increase in wind speed, decrease in humidity and reduction in tropical solar radiation. The climatological global mean air–sea heat and freshwater fluxes (1984–2006) then become 2 W/m2 and ?0.1 mg/m2 per second, respectively, down from 30 W/m2 and 3.4 mg/m2 per second for the unaltered data. However, decadal means vary from 7.3 W/m2 (1977–1986) to ?0.3 W/m2 (1997–2006). The spatial distributions of climatological fluxes display all the expected features. A comparison of zonally averaged wind stress components across ocean sub-basins reveals large differences between available products due both to winds and to the stress calculation. Regional comparisons of the heat and freshwater fluxes reveal an alarming range among alternatives; typically 40 W/m2 and 10 mg/m2 per second, respectively. The implied ocean heat transports are within the uncertainty of estimates from ocean observations in both the Atlantic and Indo-Pacific basins. They show about 2.4 PW of tropical heating, of which 80% is transported to the north, mostly in the Atlantic. There is similar good agreement in freshwater transport at many latitudes in both basins, but neither in the South Atlantic, nor at 35°N. 相似文献
20.
1961～2009年我国地面太阳辐射变化特征及云对其影响的研究 总被引：1，自引：0，他引：1
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