黔中气溶胶传输的^210Pb和^7Be示踪：Ⅱ.月及年时间尺度的剖析  

^(210)Pb and ~7Be as Tracers for Aerosol Transfers at Center Guizhou,China:Ⅱ. The Interpretation by Monthly and Yearly Intervals

作　　者：万国江[1] 郑向东[2] Lee H N Bai Z G 万恩源[1] 王仕禄[1] 杨伟[1] 苏菲 汤洁[2] 王长生[1] 黄荣贵[1] 刘鹏[6] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵州贵阳550002 [2]中国气象科学研究院,北京100081 [3]Environmental Measurements Laboratory,New York NY 10014-7447, USA [4]ISRIC-World Soil Information,Wageningen 6700 AJ, the Netherlands [5]贵州省气象局,贵州贵阳550002 [6]中国大气本底基准观象台,青海西宁810001

出　　处：《地球科学进展》2010年第5期505-514,共10页Advances in Earth Science

基　　金：国家自然科学基金面上项目“环境中Pu的地球化学运移”(编号:40873086),“黔中大气核素(Pb-210,Be-7)与气溶胶关系”(编号:40773071),“Pb-210和Be-7大气沉降通量研究”(编号:40373038),“利用7Be和210Pb示踪研究高原大气微量气体成分的输送特征”(编号:40175032);中美国际合作项目“Tracing recent climate and environmental changes by measuring lowlevel radionuclides in the Yunnan-Guizhou plateau,China(2001-2005)”资助

摘　　要：自2001年12月连续逐周在贵阳观风山附近对近地面空气210Pb-7Be浓度和沉降量的观测表明:区域性降水和气温制约近地面空气210Pb具高浓度"U"型年分布;降水量和平流层向下输送影响近地面空气7Be月均浓度的季节性变化;210Pb/7Be月均浓度比率受控于210Pb变化和富7Be气团下沉的影响。观风山与瓦里关山之间因纬度和海拔的关系,7Be比率急剧震荡,显示出海洋性贫7Be气团入侵对观风山地区的明显影响。2002—2008年间贵阳观风山近地面空气210Pb的年均浓度(2.8±0.6)mBq/m3,约为全球若干站点中最高平均浓度值的4倍;而7Be的年均浓度(4.8±0.6)mBq/m3,与全球高海拔站点长期观测的平均值相当,大约为北半球中纬度对流层顶部附近7Be浓度值(18.0mBq/m3)的1/3.8,显示出低纬度、较高海拔地区的预期水平。2003年,瓦里关山和观风山近地面空气7Be的年均浓度比为3.8,与预期的大气输送和混合作用基本一致。7Be月均浓度的增大趋势反映出受太阳黑子数减少的变化关系,其影响底线大约为4mBq/m3;7Be年均浓度波动的增大趋势反映出受太阳黑子数降低的可能影响。贵阳观风山降水中7Be和210Pb的体积加权浓度分别为0.72Bq/L和0.27Bq/L;年沉降通量分别为0.080Bq/(cm2.a)和0.031Bq/(cm2.a)。数值模拟显示出全球空气210Pb高浓度区和高沉降通量环带分布,印证了洱海和红枫湖沉积物7Be和137Cs蓄积的模拟结果。The weekly successive measurements of 210Pb and 7Be concentrations in surface air and depositional fluxes at Mt.Guanfeng/Guiyang since December of 2001 indicate that high 210Pb concentration is constrained by regional rainfall and air temperature,and shows U-pattern distribution;The seasonal variation of 7Be monthly mean concentration is influenced by the amount of precipitation and downward stratospheric current;The ratio of 210Pb and 7Be monthly mean concentrations is determined by ^210Pb variation and down flow of rich-7Be air mass.The ratio of 7Be concentration at Mt.Guanfeng/Guiyang and Mt.Waliguan fluctuates rapidly because of their latitudes and elevation,indicating an obvious influence of oceanic poor-7Be air mass invasion on Mt.Guanfeng.Annual mean concentration of 210Pb at Mt.Guanfeng/Guiyang during 2002-2008 is about 2.8-0.6 mBq/m^3,nearly 4 times of the average concentration of the highest concentrations of the global observations;4.8-0.6 mBq/m^3 for 7Be,which is equivalent to the average concentration of the highest concentrations of the global observations and 1/3.8 times of the ^7Be activity（18.0 mBq/m^3）on the top of the troposphere at middle latitude of northern hemisphere;it is anticipated in the low latitude and high elevation area.In 2003,the ratio of annual mean 7Be concentration was 3.8 at both Mt.Waliguan and Mt.Guanfeng,which is consistent with the anticipated consequence of atmospheric transportation and mixture.The increasing trend of 7Be monthly mean concentration relates to the decrease of sunspot number and the baseline of the influence for ^7Be is about 4 mBq/m^3;The increasing trend of 7Be annual mean concentration could also be influenced by sunspot number decrease.Volume-weighted concentrations of 7Be and ^210Pb in rainfall at Mt.Guanfeng/Guiyang are 0.72 Bq/L and 0.27 Bq/L,respectively;their annual depositional fluxes are 0.080 Bq/（cm^·a）and 0.031 Bq/（cm^2·a）,respectively.The numerical simulation shows global zonal distribution of ^210Pb with mosaic areas of high ai

关 键 词：气溶胶传输 210Pb-7Be 月—年时间尺度 红枫湖 洱海 

分 类 号：P402[天文地球—大气物理学与大气环境]