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1.
To assess individual direct radiative effects of diverse aerosol species on a regional scale,the air quality modeling system RAMS-CMAQ(Regional Atmospheric Modeling System and Community Multiscale Air Quality) coupled with an aerosol optical properties/radiative transfer module was used to simulate the temporal and spatial distributions of their optical and radiative properties over East Asia throughout 2005.Annual and seasonal averaged aerosol direct radiative forcing(ADRF) of all important aerosols and individual components,such as sulfate,nitrate,ammonium,black carbon(BC),organic carbon(OC),and dust at top-of-atmosphere(TOA) in clear sky are analyzed.Analysis of the model results shows that the annual average ADRF of all important aerosols was in the range of 0 to-18 W m?2,with the maximum values mainly distributed over the Sichuan Basin.The direct radiative effects of sulfate,nitrate,and ammonium make up most of the total ADRF in East Asia,being concentrated mainly over North and Southeast China.The model domain is also divided into seven regions based on different administrative regions or countries to investigate detailed information about regional ADRF variations over East Asia.The model results show that the ADRFs of sulfate,ammonium,BC,and OC were stronger in summer and weaker in winter over most regions of East Asia,except over Southeast Asia.The seasonal variation in the ADRF of nitrate exhibited the opposite trend.A strong ADRF of dust mainly appeared in spring over Northwest China and Mongolia.  相似文献   

2.
京津冀地区气溶胶时空分布及与城市化关系的研究   总被引:2,自引:1,他引:1  
张西雅  扈海波 《大气科学》2017,41(4):797-810
利用AERONET(AErosol RObotic NETwork)数据对2008~2012年Terra MODIS(MOderate-resolutionImaging Spectroradiometer)C006 3 km卫星遥感气溶胶产品在京津冀地区的适用性进行了验证,分析京津冀地区3km分辨率气溶胶光学厚度(AOD)的时空分布和变化特征。利用DMSP(Defense Meteorological Satellite System)/OLS(Operational Linescan System)夜间灯光数据作为城市化评价手段,对京津冀地区城市化与AOD时空分布之间的关系进行了研究。结果表明:(1)MODIS 3 km气溶胶产品遥感反演数据和同期AERONET监测数据在研究区具有很好的一致性,相关系数达0.91,满足期望要求;(2)时间上,2008~2012年研究区年平均AOD值在0.361~0.453之间变化,年际间变化浮动大,总体呈下降趋势;AOD春季呈明显下降趋势,夏季总体呈微弱上升趋势,秋季和冬季呈明显上升趋势;(3)空间上,2008~2012年北京、天津和河北中南部的AOD值较高,河北北边AOD值较低;四季AOD空间分布呈现较强烈季节变化,夏季最高,冬季最低;(4)夜间灯光数据和AOD时空分布不仅在空间分布上呈现较好的一致性,且2008~2012年二者的地理权重回归(GWR)模型拟合度R2达0.8左右。研究区内AOD与夜间灯光数据二者相关性显著,城市化发展水平和人类活动对气溶胶的分布有着明显的影响。  相似文献   

3.
利用中分辨率成像光谱仪(Moderate-resolution Imaging Spectroradiometer,MODIS)大气气溶胶光学厚度产品数据,采用三角剖分算法、最近邻点搜索、插值法和趋势分析法,分析新疆气溶胶光学厚度(Aerosol Optical Depth,AOD)时空变化。结果表明:(1)新疆AOD总体呈下降趋势且地域差异明显,南疆AOD明显高于北疆,高值区主要集中在塔里木盆地边缘和天山北坡经济带。(2)北疆AOD年际变化不明显。2014年最高,2005年最低,年均值在0.15~0.18。南疆则呈明显的年际变化。最高值出现在2006年,为0.42;最低值出现在2017年,为0.22。(3)新疆AOD呈明显季节变化特征。春季最大,秋季最小。(4)2003—2019年南疆环塔里木盆地北部、东南边缘和北疆沿天山北坡经济带AOD增量明显。  相似文献   

4.
In this study, a combination of satellite observations and reanalysis datasets is used to analyze the spatiotemporal distribution, classification and source of pollutants over the eastern slope of the Tibetan Plateau(ESTP). The aerosol optical depth(AOD) over the ESTP is extremely large and even larger than some important industrialized regions and deserts. The main aerosol component over the ESTP is sulfate, followed by carbonaceous and dust aerosols. Local emissions related to human activity directly contribute to the accumulation of sulfate and carbonaceous aerosols over the Sichuan Basin. In addition, in spring, abundant carbonaceous aerosols emitted from forest, grassland and savanna fires in Southeast Asia can be transported by the prevailing southwesterly wind to southern China and the ESTP. The dust AOD over the ESTP peaks in spring because of the transport from the Taklimakan and Gobi deserts. Additionally, the high aerosol loading over the ESTP is also directly related to the meteorological background. Due to the special topography, the terrain-driven circulation can trap aerosols in the Sichuan Basin and these aerosols can climb along the ESTP due to the perennial updraft. The aerosol loading is lowest in summer because of effective wet deposition induced by the strong precipitation and better dispersion conditions due to the larger vertical temperature gradients and ascending air movement enhanced by the plateau heat pump effect. In contrast,the aerosol loading is greatest in winter. Abundant anthropogenic aerosols over the ESTP may generate some climatic and environmental risks and consequently greatly influence the downstream regions.  相似文献   

5.
通过对再分析资料总气溶胶光学厚度(total aerosol optical depth,AOD)和低云云量(low cloud cover,LCC)的分析,结果表明:四川盆地秋季气溶胶与云的分布和变化主要是以全区域的一致变化,和以成都、重庆为中心的双支结构为主。气溶胶分布为双支结构时的变化更容易引起云量变化,持续时间不超过两天;气溶胶对云的影响还与二者的分布时间有关,二者高值出现的时间相近(10月),气溶胶会使高云量增加,反之使低云量增加高云量减少(9月)。   相似文献   

6.
Aerosol optical depth(AOD) is the most basic parameter that describes the optical properties of atmospheric aerosols,and it can be used to indicate aerosol content. In this study, we assimilated AOD data from the Fengyun-3 A(FY-3 A) and MODIS meteorological satellite using the Gridpoint Statistical Interpolation three-dimensional variational data assimilation system. Experiments were conducted for a dust storm over East Asia in April 2011. Each 0600 UTC analysis initialized a24-h Weather Research and Forecasting with Chemistry model forecast. The results generally showed that the assimilation of satellite AOD observational data can significantly improve model aerosol mass prediction skills. The AOD distribution of the analysis field was closer to the observations of the satellite after assimilation of satellite AOD data. In addition, the analysis resulting from the experiment assimilating both FY-3 A/MERSI(Medium-resolution Spectral Imager) AOD data and MODIS AOD data had closer agreement with the ground-based values than the individual assimilation of the two datasets for the dust storm over East Asia. These results suggest that the Chinese FY-3 A satellite aerosol products can be effectively applied to numerical models and dust weather analysis.  相似文献   

7.
The air quality model system RAMS (Regional Atmospheric Modeling System)-CMAQ (Models-3 Community Multi-scale Air Quality) coupled with an aerosol optical/radiative module was applied to investigate the impact of different aerosol mixing states (i.e., externally mixed, half externally and half internally mixed, and internally mixed) on radiative forcing in East Asia. The simulation results show that the aerosol optical depth (AOD) generally increased when the aerosol mixing state changed from externally mixed to internally mixed, while the single scattering albedo (SSA) decreased. Therefore, the scattering and absorption properties of aerosols can be significantly affected by the change of aerosol mixing states. Comparison of simulated and observed SSAs at five AERONET (Aerosol Robotic Network) sites suggests that SSA could be better estimated by considering aerosol particles to be internally mixed. Model analysis indicates that the impact of aerosol mixing state upon aerosol direct radiative forcing (DRF) is complex. Generally, the cooling effect of aerosols over East Asia are enhanced in the northern part of East Asia (Northern China, Korean peninsula, and the surrounding area of Japan) and are reduced in the southern part of East Asia (Sichuan Basin and Southeast China) by internal mixing process, and the variation range can reach 5 W m-2. The analysis shows that the internal mixing between inorganic salt and dust is likely the main reason that the cooling effect strengthens. Conversely, the internal mixture of anthropogenic aerosols, including sulfate, nitrate, ammonium, black carbon, and organic carbon, could obviously weaken the cooling effect.  相似文献   

8.
西北地区MODIS气溶胶产品的对比应用分析   总被引:3,自引:0,他引:3  
胡蝶  张镭  沙莎  王宏斌 《干旱气象》2013,(4):677-683
利用气溶胶自动监测网(AERONET)的太阳光度计(CE-318)资料,对2003-2010年西北干旱半干旱区MODIS暗像元算法和深蓝算法2种气溶胶光学厚度(AOD)产品进行对比验证,在此基础上进一步研究了该区域AOD的空间分布特征及变化趋势。结果表明,MODIS暗像元算法AOD产品在半干旱区原生植被覆盖地表精度优于深蓝算法,而西北干旱区荒漠地表深蓝算法产品精度较高。Aqua—MODIS深蓝算法AOD产品能够较好地给出我国西北荒漠亮地表地区AOD的分布及季节变化情况,AOD高值区多分布在沙尘源区,且春季AOD最大。2003~2010年,塔里木盆地、准噶尔盆地和柴达木盆地年均AOD分别在0.5、0.4和0.3附近波动;沙尘区各区域年均AOD大多呈现增加趋势。其中,塔里木盆地AOD增加趋势较大,而内蒙古西部和准噶尔盆地呈现微弱减少趋势。  相似文献   

9.
我国380nm波长气溶胶光学厚度分布特征和演变趋势   总被引:2,自引:2,他引:0       下载免费PDF全文
利用1980—2001年TOMS/ NASA逐月气溶胶光学厚度 (AOD) 资料, 通过EOF, Morlet小波分析、趋势分析和突变检验等方法, 研究了我国大气气溶胶380nm光学厚度的时空分布特征和变化趋势。结果表明:全国全年存在两个范围较大、持续时间较长的AOD高值区:南疆盆地和四川盆地; 绝大部分地区春季AOD值最大, 最小值出现的季节则有所不同; 季节差异随纬度增加而减小; AOD变化具有明显的季节性和年际振荡特征; 年平均AOD呈明显增加趋势, 20世纪80年代末90年代初增加趋势有所减弱。  相似文献   

10.
气溶胶已是东亚地区最主要的大气污染物之一,其时空分布会受到东亚季风气候的影响。利用2000~2014年MODIS/AOD(Moderate-resolution Imaging Spectroradiometer/Aerosol Optical Depth)和NCEP月平均气象场再分析资料,本研究分析了东亚冬季风长期变化趋势、气溶胶年际变化规律,探讨了东亚冬季风强度变化对气溶胶分布的影响。基于MODIS/AOD,发现近10年东亚地区冬季AOD呈现上升趋势,最大值为2007年的0.44,高值区覆盖四川盆地、华北平原及长江中下游大部分地区。风场特征类冬季风指数分析表明,东亚冬季风存在明显的年际和年代际差异,近年出现逐渐减弱的趋势。强冬季风年,海陆气压差增大、东亚大槽加深增强,东亚地区偏北风异常,风场的增强将引导更多冷空气南下,从而给东亚大部分地区带来明显的降温天气;弱年相反。气象场差异引起气溶胶分布变化,强年较强的偏北风将气溶胶向南方输送,东亚地区AOD出现“北低南高”的空间分布;弱年偏北风较弱,导致气溶胶集中在华北平原一带,AOD出现“北高南低”的空间分布。  相似文献   

11.
Understanding the role of aerosols in global and regional climate change requires the long-term measurements of aerosol optical properties. We use an indirect method to infer aerosol optical depths (AODs) based on atmospheric visibility and water vapor pressure measured at 504 key climate stations in eastern China (east of 100° E) over 1951–2002. Inferred AODs are compared with the MODIS satellite measurements for year of 2002. Results show that AODs averaged over 1951–2000 exhibit large values in Sichuan Basin and Changjiang River Delta, and there are two belts of high AODs, one from Beijing to South China by the middle reaches of Changjiang River and the other from Beijing to Changjiang Delta. Inferred AODs in eastern China show the lowest value in 1960s, increase dramatically in 1980s, and reach maximum in 1990s. The ratios of the regional and decadal mean AOD in 1950s, 1960s, 1970s, 1980s, and 1990s to that in 1960s are 1.085, 1.0, 1.066, 1.195, and 1.22, respectively. Statistical analysis shows that variations in AODs correlate with the changes in precipitation and air temperature in eastern China over the past 50 years. Correlation coefficients between annual mean AOD and precipitation are 0.39, 0.37, and 0.57 in the upper (Sichuan Basin), middle, and lower reaches of the Changjiang River, respectively. In the Sichuan Basin, the increase in annual mean AOD correlates with the reduction in air temperature with a correlation coefficient of ?0.33 at 95% confidence level.  相似文献   

12.
Industrial pollution has a significant effect on aerosol properties in Changsha City, a typical city of central China. Therefore, year-round measurements of aerosol optical, radiative and chemical properties from 2012 to 2014 at an urban site in Changsha were analyzed. During the observation period, the energy structure was continuously optimized, which was characterized by the reduction of coal combustion. The aerosol properties have obvious seasonal variations. The seasonal average aerosol optical depth (AOD) at 500 nm ranged from 0.49 to 1.00, single scattering albedo (SSA) ranged from 0.93 to 0.97, and aerosol radiative forcing at the top of the atmosphere (TOA) ranged from ?24.0 to 3.8 W m?2. The chemical components also showed seasonal variations. Meanwhile, the scattering aerosol, such as organic carbon, SO42?, NO3?, and NH4+ showed a decrease, and elemental carbon increased. Compared with observation in winter 2012, AOD and TOA decreased by 0.14 and ?1.49 W m?2 in winter 2014. The scattering components, SO42?, NO3? and NH4+, decreased by 12.8 μg m?3 (56.8%), 9.2 μg m?3 (48.8%) and 6.4 μg m?3 (45.2%), respectively. The atmospheric visibility and pollution diffusion conditions improved. The extinction and radiative forcing of aerosol were significantly controlled by the scattering aerosol. The results indicate that Changsha is an industrial city with strong scattering aerosol. The energy structure optimization had a marked effect on controlling pollution, especially in winter (strong scattering aerosol).  相似文献   

13.
开发AVHRR可见光通道反演陆地气溶胶光学厚度 (AOD) 的算法对于研究长时间序列AOD的变化有重要意义。AVHRR由于缺少2.1 μm通道而不能采用MODIS的暗背景算法,该文利用背景合成算法进行陆地AOD反演。背景合成算法是指假设一段时间内地表反射率变化不大且会出现相对清洁大气, 采用最小值合成即可得到地表反射率,再通过辐射传输模式6S制作的查算表查算得到AOD的反演结果。将此算法应用到2009年AVHRR中国部分陆地区域 (15°~45°N,75°~135°E) 得到AOD的时空分布,将反演结果与同期Aqua/MODIS的MOD04 AOD产品进行对比分析表明,华北和华东地区的反演效果较好,西北地区结果较差。以长江三角洲地区为例可知,AVHRR AOD产品与MODIS AOD产品以及AERONET观测的AOD相比相关系数基本在0.6以上,从时间变化规律来看,AVHRR AOD和MODIS AOD产品年变化趋势具有很好的一致性。该文为建立长时间序列AVHRR AOD数据集提供了一个较为可行的方法。  相似文献   

14.
基于新耦合气溶胶气候模式FGOALS-f3-L模拟分析了2002-2011年青藏高原地区气溶胶时空分布特征.结果表明:青藏高原地区,沙尘,硫酸盐,碳质气溶胶(包括黑碳,有机碳和混合碳)地表质量浓度分别占比为53.6%,32.2%,14.2%;在拉萨站点,模拟的气溶胶地表质量浓度被低估,尤其是黑碳和有机碳气溶胶;模拟的气...  相似文献   

15.
庄炳亮  王体健  李树 《高原气象》2009,28(5):1095-1104
将区域气候模式(RegCM3)与对流层大气化学模式(TACM)耦合, 建立区域气候化学模拟系统(RegCCMS), 用以模拟研究中国地区黑碳气溶胶的空间分布、 第一间接辐射强迫及其气候效应。利用RegCCMS模式对2003年1月和7月进行模拟, 结果表明, 我国黑碳气溶胶主要集中在四川、 河北、 山东等地, 1月份浓度最高值中心在四川, 达到4 μg·m-3; 而在7月则出现在华中地区, 高值中心值为3.5 μg·m-3。地面浓度的季节差异不是很明显。1月和7月由黑碳气溶胶所造成的第一间接辐射强迫全国平均值分别为-0.389 W·m-2和-1.18 W·m-2, 局部地区达到-4~-4.5 W·m-2。敏感性试验结果表明, 考虑黑碳气溶胶的第一间接气候效应后, 使得近地面气温下降, 降水减少, 1月变化的平均值分别为-0.025K和-0.0027 mm·d-1, 7月变化的平均值分别为-0.16K和-0.095 mm·d-1, 在不同季节和地区, 气温和降水的变化存在明显差异。  相似文献   

16.
The spatial distributions and interannual variations of aerosol concentrations,aerosol optical depth(AOD) ,aerosol direct radiative forcings,and their responses to heterogeneous reactions on dust surfaces over East Asia in March 2006-10 were investigated by utilizing a regional coupled climate-chemistry/aerosol model. Anthropogenic aerosol concentrations(inorganic+carbonaceous) were higher in March 2006 and 2008,whereas soil dust reached its highest levels in March 2006 and 2010,resulting in stronger aerosol radiative forcings in these periods.The domain and five-year(2006-10) monthly mean concentrations of anthropogenic and dust aerosols,AOD,and radiative forcings at the surface(SURF) and at the top of the atmosphere(TOA) in March were 2.4μg m-3,13.1μg m-3,0.18,-19.0 W m-2,and-7.4 W m-2,respectively.Heterogeneous reactions led to an increase of total inorganic aerosol concentration;however,the ambient inorganic aerosol concentration decreased,resulting in a smaller AOD and weaker aerosol radiative forcings.In March 2006 and 2010,the changes in ambient inorganic aerosols,AOD,and aerosol radiative forcings were more evident.In terms of the domain and five-year averages,the total inorganic aerosol concentrations increased by 13.7%(0.17μg m-3) due to heterogeneous reactions,but the ambient inorganic aerosol concentrations were reduced by 10.5%(0.13μg m-3) .As a result,the changes in AOD,SURF and TOA radiative forcings were estimated to be-3.9%(-0.007) ,-1.7%(0.34 W m-2) ,and-4.3%(0.34 W m-2) ,respectively,in March over East Asia.  相似文献   

17.
结合2006年最新的气溶胶排放源资料,以NCEP/NCAR再分析资料为气象场,驱动大气化学传输模式MATCH(Model of Atmospheric Transport and Chemistry),模拟了2006年中国地区硫酸盐、黑碳和沙尘气溶胶的质量浓度分布及其季节变化。模拟的气溶胶光学厚度(AOD)结果与CSHNET观测网数据比较分析后发现,基于21个观测站的61组月平均数据与相应模拟结果的相关系数为0.63。模拟结果表明:2006年中国地区硫酸盐气溶胶高值区主要分布在中国的四川盆地、华北及长江流域等工业较发达地区,而且具有明显的季节变化,四川盆地及长江以南地区,硫酸盐气溶胶1月份浓度高于7月份,长江以北的大部分地区,7月份浓度高于1月份;黑碳气溶胶主要分布在黄河、长江中下游地区及华南等地区,1月份浓度高于7月份;沙尘气溶胶主要分布在内蒙古中部沙漠地区,4月份浓度最高,7月份次之,其他月份较少。  相似文献   

18.
利用MODIS卫星遥感光学厚度产品,分析了四川盆地光学厚度分布和季节变化特征。由于受沙尘天气的影响,春季四川盆地具有最大的平均光学厚度。盆地内几个大值区中,西部成都一带的中心常年维持,季节变化小;南部中心位于宜宾到重庆沿长江流域一带;东部南充到重庆间的大值中心,季节变化大,在夏季消失。光学厚度分布和季节变化的数据结果为研究区域气候变化提供了依据。  相似文献   

19.
We compared April to September retrievals of total, fine-mode (sub-micron), and coarse-mode (super-micron) aerosol optical depth (AOD) from the Aerosol Robotic Network (AERONET) with simulations from a global three-dimensional chemical transport model, the Goddard Earth Observing System (GEOS-Chem), across five Arctic stations and a four-year sampling period. It was determined that the AOD histograms of both the retrievals and the simulations were better represented by a lognormal distribution and that the successful simulation of this empirical feature as well as its consequences (including a better model versus retrieval coefficient of determination in log-log AOD space) represented a general indicator of model evaluation success. Seasonal (monthly averaged) AOD retrievals were sensitive to the way in which the averaging was performed; this was ascribed to the presence of highly variable fine-mode smoke in the western Arctic. The retrieved and modelled station-by-station fine-mode AOD averages showed a peak in April/May that decreased over the summer, while the model underestimated the fine-mode AOD by an average of about 0.004 (~6%). Both the retrievals and simulations showed seasonal coarse-mode AOD variations with a peak in April/May that was attributed to Asian and/or Saharan dust. The model's success in capturing such weak seasonal events helps to confirm the relevance of the separation of the fine and coarse modes and the general validity of model estimates in the Arctic.  相似文献   

20.
四川盆地作为我国一个特殊的大气气溶胶污染区域,亟待厘清其大气污染时空变化与独特盆地地形影响相关机理。本文综述了近年来一系列相关研究成果,包括:(1)揭示了四川盆地大气环境变化中大地形影响作用,青藏高原东侧区域气溶胶空间分布“避风港”效应,以及大地形热力强迫对盆地空气质量变化的“气候调节”影响; (2)探明了四川盆地大气边界层结构对大气气溶胶变化的影响,冬季重霾期间大气边界层垂直结构变化特征及其相关PM2.5物理化学特性;(3)明晰了大气气溶胶在四川盆地暴雨过程中的重要作用机理,以及四川盆地气溶胶高污染分布导致的降水分布型态的气候变化。这些研究提升了四川盆地气溶胶污染形成机理及大地形对大气环境变化影响效应的科学认识,并表明未来应该深入研究四川盆地地形背景下独特大气边界层结构,人为与自然源排放和环境大气物理-化学过程变化。   相似文献   

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