首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The long-term trends of total surface solar radiation(SSR),surface diffuse radiation,and surface air temperature were analyzed in this study based on updated 48-yr data from 55 observational stations in China,and then the correlation between SSR and the diurnal temperature range(DTR) was studied.The effect of total solar radiation on surface air temperature in China was investigated on the basis of the above analyses.A strong correlation between SSR and DTR was found for the period 1961-2008 in China.The highest correlation and steepest regression line slope occurred in winter,indicating that the solar radiation effect on DTR was the largest in this season.Clouds and water vapor have strong influences on both SSR and DTR,and hence on their relationship.The largest correlations between SSR and DTR occurred in wintertime in northern China,regardless of all-day(including clear days and cloudy days) or clear-day cases.Our results also showed that radiation arriving at the surface in China decreased significantly during 1961-1989(dimming period),but began to increase during 1990-2008(brightening period),in agreement with previous global studies.The reduction of total SSR offset partially the greenhouse warming during 1961-1989.However,with the increase of SSR after 1990,this offsetting effect vanished;on the contrary,it even made a contribution to the accelerated warming.Nonetheless,the greenhouse warming still played a controlling role because of the increasing of minimum and mean surface temperatures in the whole study period of 1961-2008.We estimated that the greenhouse gases alone may have caused surface temperatures to rise by 0.31-0.46℃(10 yr) 1 during 1961-2008,which is higher than previously estimated.Analysis of the corresponding changes in total solar radiation,diffuse radiation,and total cloud cover indicated that the dimming and brightening phenomena in China were likely attributable to increases in absorptive and scattering aerosols in the atmosphere,respectively.  相似文献   

2.
全球气候模式对东亚地区地表短波辐射的模拟检验   总被引:2,自引:1,他引:1       下载免费PDF全文
利用WCRPCMIP3提供的18个全球气候模式输出结果, 检验了其对东亚地区地表短波辐射的模拟能力, 结果表明:多模式集合的多年平均地表短波辐射模拟偏高约8.7 W/m 2, 晴空地表短波辐射模拟偏高约3.4 W/m 2, 地表短波云辐射强迫模拟偏低约5.3 W/m2, 模式间的标准差分别达到9.6, 7.8 W/m2和8 W/ m2; 多模式集合能够很好地模拟出地表短波辐射的纬向平均季节变化的位相特征, 但在量值上还有较大的差距; 模拟偏差分析表明, 多模式集合的区域年平均地表短波辐射、晴空地表短波辐射、地表短波云辐射强迫的均方根偏差分别为34.7, 17.1 W/m 2和29.1 W/ m2, 表明云在地表短波辐射的模拟偏差中起着重要作用; 多模式集合能够很好地模拟出地表入射短波辐射年变化的线性减小趋势, 但模式高估了晴空入射辐射的减小趋势, 而模拟的云辐射强迫变化趋势与ERA 40完全相反。  相似文献   

3.
In this study, the annual and seasonal variations of all-sky and clear-sky surface solar radiation (SSR) in the eastern and central Tibetan Plateau (TP) during the period 1960–2009 are investigated, based on surface observational data, reanalyses and ensemble simulations with the global climate model ECHAM5-HAM. The mean annual all-sky SSR series shows a decreasing trend with a rate of ?1.00 Wm?2 decade?1, which is mainly seen in autumn and secondly in summer and winter. A stronger decrease of ?2.80 Wm?2 decade?1 is found in the mean annual clear-sky SSR series, especially during winter and autumn. Overall, these results confirm a tendency towards a decrease of SSR in the TP during the last five decades. The comparisons with reanalysis show that both NCEP/NCAR and ERA-40 reanalyses do not capture the decadal variations of the all-sky and clear-sky SSR. This is probably due to a missing consideration of aerosols in the reanalysis assimilation model. The SSR simulated with the ECHAM5-HAM global climate model under both all-sky and clear-sky conditions reproduce the decrease seen in the surface observations, especially after 1980. The steadily increasing aerosol optical depth (AOD) at 550 nm over the TP in the ECHAM5-HAM results suggests transient aerosol emissions as a plausible cause.  相似文献   

4.
利用1961~2019年中国东北地区测站逐日降水资料、美国国家环境预报中心/大气研究中心的月平均再分析资料、NOAA重构的月平均海温和向外长波辐射资料,采用统计诊断方法,从年际时间尺度上分析了东北春季透雨早晚环流特征和前期海温,尤其是热带印度洋海温强迫的联系。结果表明:春季透雨日期与4月降水量的变化具有显著的一致性,典型透雨偏早年的开始时间集中在4月中下旬,偏晚年的开始时间集中在5月中下旬;4月东北亚上空500 hPa位势高度场上,若呈自西向东的“? +”异常环流分布,东北地区以偏南风和气旋性环流为主,有利于水汽输送,春季透雨开始偏早,反之,春季透雨开始偏晚;2~3月热带印度洋暖海温异常是中国东北地区春季透雨偏早的重要稳定影响源之一,其可能机制是,若热带印度洋全区一致海温模态呈正位相,有利于4月西北太平洋地区呈异常反气旋,东北亚地区500 hPa环流异常类似春季透雨偏早年形势,东北地区位于200 hPa西风急流出口区右侧,垂直上升运动增强,呈现出多雨形势。  相似文献   

5.
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   

6.
Surface solar radiation(SSR) is a key component of the energy budget of the Earth’s surface, and it varies at different spatial and temporal scales. Considerable knowledge of how and why SSR varies is crucial to a better understanding of climate change, which surely requires long-term measurements of high quality. The objective of this study is to introduce a value-added SSR dataset from Oct 2004 to Oct 2019 based on measurements taken at Xianghe, a suburban site in the North China Plain; two va...  相似文献   

7.
基于中国大陆中东部484个气象站1980—2009年日照时数、总云量、能见度数据,按区域分析了地表太阳辐射长期变化特征及云量和气溶胶对辐射变化的可能影响,深入理解地表太阳辐射变化趋势成因。中国大陆中东部地区地表太阳辐射呈下降趋势(-0.7 Wm-2/10a)。从季节变化分析,下降趋势主要集中于夏季(-2.7 Wm-2/10a);从区域分析,下降幅度最大的为华北地区(-3.9 Wm-2/10a),该区云量不明显上升、能见度明显下降,且地表太阳辐射与云量低频部分相关系数(年代际变率)约-0.25,与气溶胶低频部分相关系数达-0.87,以此推测华北地区地表辐射的长期变化是气溶胶与总云量共同作用的结果。华南地区春季辐射上升(4.2 Wm-2/10a)则归因于总云量的下降(-2.1%/10a)。地表太阳辐射与总云量高频部分的相关系数(年际变率)达到-0.85以上,表明地表太阳辐射的年际短期变率主要贡献是来自于总云量的年际变化。  相似文献   

8.
地形起伏对模式地表长波辐射计算的影响   总被引:7,自引:6,他引:1  
陈斌  张耀存  丁裕国 《高原气象》2006,25(3):406-412
初步探讨了数值模式中次网格区地形起伏(高度、坡度)对长波辐射计算的影响。结果表明,地形高度的次网格变化对辐射计算结果的影响较小,其相对误差一般<2%,但不同分辨率的地形高度场会产生不同的坡度计算误差,低分辨率地形资料所计算的坡度分布相差不大,但坡度的量级存在较大偏差。地形的分辨率越高,实际计算结果的偏差越小。而高分辨率地形资料计算实例表明,地形坡度引起的区域相对辐射误差可达到10%以上。因此,在数值模式中,网格区地表长波辐射计算结果对地形起伏的敏感性应给予足够的重视。  相似文献   

9.
A comparative analysis between cloud-to-ground (CG) lightning density and terrain parameters (altitude and terrain slope) in South Brazil is presented. This region is characterized by a contrasting topography, where a mountain chain separates lower (depression) and higher (plateau) landscapes. The altitude and terrain slope data were obtained from the Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM). Two years of CG lightning data (from June 2005 to May 2007) obtained by the Brazilian Lightning Detection Network (BrasilDAT) were used in the study. To avoid intracloud contamination, positive CG flashes with peak currents less than 20 kA were removed from the data set. A relative detection efficiency model was used to correct the lightning data. The results indicate that, for localized areas (following the mountain shape) within this region of Brazil, the CG lightning density is correlated with the terrain slope and not the altitude. This suggests that terrain slope has more influence than altitude on the thunderstorm occurrence and lightning activity. In addition, a temporal analysis shows that over high altitude regions the diurnal variation (amplitude) of lightning activity is stronger and the peak occurs 1 h earlier than over low altitude regions.  相似文献   

10.
Surface solar radiation (SSR) can affect climate, the hydrological cycle, plant photosynthesis, and solar power. The values of solar radiation at the surface reflect the influence of human activity on radiative climate and environmental effects, so it is a key parameter in the evaluation of climate change and air pollution due to anthropogenic disturbances. This study presents the characteristics of the SSR variation in Nanjing, China, from March 2016 to June 2017, using a combined set of pyranometer and pyrheliometer observations. The SSR seasonal variation and statistical properties are investigated and characterized under different air pollution levels and visibilities. We discuss seasonal variations in visibility, air quality index (AQI), particulate matter (PM10 and PM2.5), and their correlations with SSR. The scattering of solar radiation by particulate matter varies significantly with particle size. Compared with the particulate matter with aerodynamic diameter between 2.5 μm and 10 μm (PM2.5?10), we found that the PM2.5 dominates the variation of scattered radiation due to the differences of single-scattering albedo and phase function. Because of the correlation between PM2.5 and SSR, it is an effective and direct method to estimate PM2.5 by the value of SSR, or vice versa to obtain the SSR by the value of PM2.5. Under clear-sky conditions (clearness index ≥0.5), the visibility is negatively correlated with the diffuse fraction, AQI, PM10, and PM2.5, and their correlation coefficients are ?0.50, ?0.60, ?0.76, and ?0.92, respectively. The results indicate the linkage between scattered radiation and air quality through the value of visibility.  相似文献   

11.
Solar radiation is an important energy source for plants on the earth and also a major component of the global energy balance.Variations in solar radiation incident at the earth's surface profoundly affect the human and terrestrial environment,including the climate change.To provide useful information for predicting the future climate change in China,distinctive regional features in spatial and temporal variations of the surface solar radiation (SSR) and corresponding attributions (such as cloud and aerosol) are analyzed based on SSR observations and other meteorological measurements in North and East China from 1961 to 2007.Multiple models,such as the plane-parallel radiative transfer model,empirical and statistical models,and corrclation and regrcssion analysis methods are used in the study.The results are given as follows.(1) During 1961-2007,the total SSR in North China went through a process from quickly “dimming” to slowly “dimming”,while in East China,a significant transition from “dimming” to “brightening” occurred.Although there are some differences between thc two regional variation trends,long-term variations in SSR in the two regions are basically consistent with the observation worldwide.(2) Between the 1960s and 1980s,in both North and East China,aerosols played a critical rolc in the radiation dimming.However,after 1989,different variation trends of SSR occurred in North and East China,indicating that aerosols were not the dominant factor.(3) Cloud cover contributed less to the variation of SSR in North China,but was thc major attribution in East China and played a promoting role in the reversal of SSR from dimming to brightening,especially in the “remarkable brightening” period,with its contribution as high as 70%.  相似文献   

12.
胡娟  李华宏  闵颖 《气象科技》2011,39(5):552-557
低纬高原地区的气象要素变化除了受大气环流因子的影响外,高程、坡度、坡向等地理因子的作用不可忽视.以云南省为例,应用云南省125个气象站的降水、温度、露点温度等气象资料,与各站点的经度、纬度、高程、坡向、坡度等地理因子建立关系模型,运用多元回归方法,求得回归系数,代入随机抽取的检验站点的地理因子回归方程式中,得出拟合量,...  相似文献   

13.
Solar radiation is an important energy source for plants on the earth and also a major component of the global energy balance. Variations in solar radiation incident at the earth’s surface profoundly affect the human and terrestrial environment, including the climate change. To provide useful information for predicting the future climate change in China, distinctive regional features in spatial and temporal variations of the surface solar radiation (SSR) and corresponding attributions (such as cloud and aer...  相似文献   

14.
The slope of the tropopause is calculated from the data of its height in the points of a regular grid. From the NCEP Reanalysis-2 for 1990–2007, the slope angles are calculated of the tropopause approximated by different constant values of Ertel potential vorticity within the latitude band of 30°–70° N. Effects of horizontal resolution of the data under use on the calculation results are studied on the basis of ten-day samples of objective analysis by UKMO, NCEP, and operative objective analysis of Hydrometeorological Center of Russia in different seasons of 2009.  相似文献   

15.
山地上冰雹云的数值试验研究   总被引:12,自引:11,他引:1  
建立了一个适用于复杂地形的冰雹云模式。模式是二维、弹性、非静力、采用地形跟随价值、包含双变参数冰相微物理过程参数化。使用实测的初值条件和环境场进行试验。对理论对称型山地的不同初始位温扰动作模拟。结果表明,当初始位温扰动在迎风坡和山顶时冰雹云发展较弱,而当初始位温扰动在背风坡和平原时冰雹云发展较强。当初始位温扰动在背风坡时冰雹云的降雹量约为当初始位温扰动在迎风坡时冰雹云降雹量的6倍。山地上冰雹云的发  相似文献   

16.
山地地表太阳辐射受坡度、坡向及地形遮蔽等影响,导致区域地表所接收的连续分布的太阳辐射量较难测量,而针对山地地表太阳辐射估算已成为目前研究的一个重点。为定量分析山地地表太阳辐射,本文利用Landsat8遥感影像、数字高程模型及气象观测数据计算相关参数,采用已有的太阳直射模型、天空散射模型和周围地形反射模型,综合估算研究区山地地表特定时刻的瞬时太阳辐射,同时根据气象站点获取的逐时太阳辐射和日总辐射量数据对结果进行验证。结果表明:该模型估算的山地瞬时太阳辐射误差均值为13.56 W/m2,日总辐射量误差均值为1.49 MJ/m2,估算值与观测值存在较好的一致性,结果误差小,精度高,参数可靠。山地太阳辐射分布与地形地貌密切相关,总体上阳坡大于阴坡,山脊大于山谷。山区太阳辐射随坡度增大而递减,同时受坡向、植被覆盖度等因素影响,坡面辐射量在一定坡度有略微上升趋势,当坡度大于太阳天顶角时,辐射量下降明显。山区受植被覆盖影响,随着地表植被的增加,地表辐射量呈下降趋势。   相似文献   

17.
以新疆区域500 m×500 m分辨率的数字高程模型(DEM)数据为主要数据源,在提取纬度、坡度、坡向等地形要素栅格数据的基础上,使用考虑地形遮蔽的分布式计算模型,完成了新疆区域全年每日可照时间的数值模拟计算,分析了其时空变化特征,讨论了地形因子对可照时间的影响,结果表明:对新疆而言,可照时间7月最长,为441 h;12月最短,为266 h,区域内可照时间的离散度较大,主要原因是地形差异所致;海拔高于1500 m的山区对全区可照时间标准差的贡献率达到了80.1%;冬夏两季有较为显著的纬向分布特征,三大山脉地区可照时间与同纬度平地相比差异明显,表现出可照时间的地域性分布特征;地形对可照时间的影响比较明显,坡度越大可照时间越少;坡向对可照时间的影响主要表现在冬季,大致为可照时间南坡多、北坡少;随着地形开阔度的增大,可照时间有较为明显的增加。  相似文献   

18.
基于皖西大别山岳西县常年(1957~1993年)和临时测站资料以及有关的研究成果,讨论了山区作物气候生产潜力估算中有参数的计算和修正问题。给出了地形因子(海拔高度、坡向、坡度)订正后的光温水参数资料,研究了适用于大别山区不同高度上水平地表面的作物气候生产潜力计算方法,并计算了不同高度、不同坡向、不同坡度的作物气候生产潜力。  相似文献   

19.
An examination of current‐meter data gathered in 1967/68 on the continental shelf and slope off Nova Scotia has shown that meteorological forcing is an important source of energy. The response of currents to wind forcing is concentrated in a frequency band of 2.5 to 7 days. Daily mean currents of up to 25 cm/s appear to be associated with wind‐stress events. The highest correlations between wind and current are for the alongshore components of these variables. Wind‐induced currents may have been responsible for an intrusion of slope water onto the shelf which was observed in hydrographic sections from October and December 1968. Long data series (up to 167 days) formed by patching together shorter records demonstrate the existence of distinct low‐frequency variability at periods greater than 10 days. Some aspects of these motions suggest the presence of topographic Rossby waves on the shelf and slope. However, spatial and temporal coverage of data are not sufficient to define the sources of this variability.  相似文献   

20.
Between 1975 and 1977, the Centre Scientifique et Technique du Bâtiment (CSTB) carried out a study of the overspeed effect over a hill in the surface boundary layer. The hill in question was situated in open country and had a drop of about 100 m for an average slope of 8%. The experimental equipment consisted of three 25 m high masts placed along the upwind slope of the hill. Each mast was equipped with four Gill Propeller anemometers. The data set analyzed consisted of 65 recordings of strong winds which had an average velocity greater than 6 m s-1.Near the ground, local topographic effects and inhomogeneous roughness along the slope have the same influence on the overspeed effect as the mean slope of the hill. The overspeed is proportional to the upwind slope, but on the other hand, the turbulence structure does not seem to be disturbed by the hill.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号