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861.
862.
863.
A coupled chemical/dynamical model (SOCOL-SOlar Climate Ozone Links) is
applied to study the impacts of future enhanced CO and NOx emissions
over eastern China on regional chemistry and climate. The result shows that
the increase of CO and NOx emissions has significant effects on
regional chemistry, including NOx, CO, O3, and OH concentrations.
During winter, the CO concentration is uniformly increased in the northern
hemisphere by about 10 ppbv. During summer, the increase of CO has a
regional distribution. The change in O3, concentrations near eastern
China has both strong seasonal and spatial variations. During winter, the
surface O3, concentrations decrease by about 2 ppbv, while during summer
they increase by about 2 ppbv in eastern China. The changes of CO, NOx,
and O3, induce important impacts on OH concentrations. The changes in
chemistry, especially O3, induce important effects on regional climate.
The analysis suggests that during winter, the surface temperature decreases
and air pressure increases in central-eastern China. The changes of
temperature and pressure produce decreases in vertical velocity. We should
mention that the model resolution is coarse, and the calculated
concentrations are generally underestimated when they are compared to
measured results. However, because this model is a coupled
dynamical/chemical model, it can provide some useful insights regarding the
climate impacts due to changes in air pollutant emissions. 相似文献
864.
通过对MODIS反演的地表温度与四川盆地自动气象站观测的准同步地面空气温度Ta和0 cm地温Ts的相关分析,结果表明:对于非均匀下垫面,卫星反演地表温度TLS分别与Ta和Ts的相关系数稳定性都不好,不同卫星过境时间的相关系数差异很大。但(Ts-TLS)与(Ts-Ta)却有着既显著又稳定的线性相关,不同卫星过境时间的相关系数都达到0.8以上,具有良好的相关性。基于卫星反演地表温度和空气温度的地温统计模型,其标准误差为4.85 ℃。 相似文献
865.
利用卫星遥感资料估算区域尺度空气温度 总被引:5,自引:0,他引:5
空气温度是地球大气系统能量和水分循环的关键参数,气象台站观测的空气温度是单点观测的,空间代表性较差,在区域尺度模型中应用还存在一些问题,作者提出了一个从卫星遥感资料直接反演空气温度的新方法。基于NOAAAVHRR资料反演的地表温度(Land Surface Temperature,T_(LS))和地面观测的空气温度(Air Temperature,T_a)的相关关系,建立了稀疏植被区域不同高程范围的空气温度遥感估算统计方法;基于NDVI和T_(LS)的梯形空间特征关系,建立了在中、高植被覆盖区域的空气温度遥感估算物理方法。经检验,稀疏植被区域空气温度反演绝对误差在1.5~1.8℃之间,中、高植被覆盖区域空气温度反演平均绝对误差为1.61℃,表明作者提出的空气温度遥感反演方法是可行的。 相似文献
866.
Continuous Measurement of Number Concentrations and
Elemental Composition of Aerosol Particles
for a Dust Storm Event in Beijing 总被引:1,自引:0,他引:1
A continuous measurement of number size distributions and chemical composition of aerosol particles was conducted in Beijing in a dust storm event during 21-26 March 2001. The number concentration of coarse particles ( 〉2μm) increased more significantly than fine particles ( 〈2μm) during the dust storm due to dust weather, while the anthropogenic aerosols collected during the non-dust-storm period tended to be associated with fine particles. Elemental compositions were analyzed by using proton-induced X-ray emission (PIXE). The results show that 20 elements in the dust storm were much higher than in the non-dust-storm period. The calculated soil dust concentration during the dust storm was, on average, 251.8μg m^-3, while it was only 52.1μg m^-3 on non-dust-storm days. The enrichment factors for Mg, A1, P, K, Ca, Ti, Mn, Fe, C1, Cu, Pb, and Zn show small variations between the dust storm and the non-dust-storm period, while those for Ca, Ni and Cr in the dust storm were much lower than those in the non-dust-storm period due to significant local emission sources. A high concentration and enrichment factor for S were observed during the dust storm, which implies that the dust particles were contaminated by aerosol particles from anthropogenic emissions during the long-range transport. A statistical analysis shows that the elemental composition of particles collected during the dust storm in Beijing were better correlated with those of desert soil colleted from desert regions in Inner Mongolia. Air mass back-trajectory analysis further confirmed that this dust storm event could be identified as streaks of dust plumes originating from Inner Mongolia. 相似文献
867.
Prediction Research of Climate Change Trends over North China in the Future 30 Years 总被引:1,自引:0,他引:1 下载免费PDF全文
LIU Yanxiang YAN Jinghui WU Tongwen GUO Yufu CHEN Lihu WANG Jianping 《Acta Meteorologica Sinica》2008,22(1):42-50
A simulation of climate change trends over North China in the past 50 years and future 30 years was performed with the actual greenhouse gas concentration and IPCC SRES B2 scenario concentration by IAP/LASG GOALS 4.0 (Global Ocean-Atmosphere-Land system coupled model), developed by the State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS). In order to validate the model, the modern climate during 1951-2000 was first simulated by the GOALS model with the actual greenhouse gas concentration, and the simulation results were compared with observed data. The simulation results basically reproduce the lower temperature from the 1960s to mid-1970s and the warming from the 1980s for the globe and Northern Hemisphere, and better the important cold (1950 1976) and warm (1977-2000) periods in the past 50 years over North China. The correlation coefficient is 0.34 between simulations and observations (significant at a more than 0.05 confidence level). The range of winter temperature departures for North China is between those for the eastern and western China's Mainland. Meanwhile, the summer precipitation trend turning around the 1980s is also successfully simulated. The climate change trends in the future 30 years were simulated with the CO2 concentration under IPCC SRES-B2 emission scenario. The results show that, in the future 30 years, winter temperature will keep a warming trend in North China and increase by about 2.5~C relative to climate mean (1960-1990). Meanwhile, summer precipitation will obviously increase in North China and decrease in South China, displaying a south-deficit-north-excessive pattern of precipitation. 相似文献
868.
根据2008年4—7月黄山大气气溶胶观测资料,研究了气溶胶粒子的数浓度、谱分布特征及其与气象因子的关系,探讨了雾天和非雾天气溶胶颗粒物时间和尺度分布特点。分析发现,黄山光明顶春、夏季大气气溶胶数浓度的平均值分别为3.14×103个/cm3和1.80×103个/cm3,其中超细粒子(粒径小于0.1μm的粒子)在春夏季分别约占总粒子数浓度的79%和68%;高数浓度值集中在粒径0.04~0.12μm;积聚模态气溶胶粒子(0.1~1.0μm)在体积浓度分布和表面积分布中占很大比例。结合气象资料比较了雾天与非雾天气溶胶分布的差异,发现细粒子浓度非雾天大于雾天,而气溶胶数浓度与温度呈正相关,与相对湿度成反相关。结果还发现,黄山在春季以西北风和偏南风为主,西北风时气溶胶数浓度较高,在夏季主要以偏南风,特别是西南风为主,但是气溶胶数浓度的高值多发生在偏东风的条件下。 相似文献
869.
利用北京城区污染观测站2006~2013年夏季可吸入颗粒物PM10逐日浓度检测资料,挑选所有PM10浓度大于150μg/m~3的个例,合成分析华北及北京地区风场变化情况,发现风速在污染当天变化不明显,南风与PM10的相关性普遍为正,污染当天各区南风增加较大,太行山一带甚至增长了5倍。南风异常可能会使河北、山东等地污染物向北京输送,造成北京大气污染。同时我们分析北京夏季空气污染时大气环流特征。在500 h Pa与200 h Pa,北京和内蒙古上空有显著的高压异常。在850 h Pa,环流场表现为东正西负的高度场异常,其中北京在正负异常分界线上。低层气压梯度异常会造成北京和以南地区南风异常。同时,我们发现北京污染天气伴随的高空环流异常具有准定常特征。在污染前4天,蒙古上空存在一个显著的高层高压异常。该高压异常增强并向南延伸,在污染当天控制北京和内蒙古。在污染消退期,该异常也逐渐消退。但在消退后第四天,北京和内蒙古上空依然受高压异常控制。这表明北京夏季污染和高空准定常环流异常有关。 相似文献
870.