利用基于光腔衰荡光谱(Cavity Ring Down Spectroscopy,CRDS)技术自组装的大气CO2在线观测系统,于2010年9月—2011年8月在云南香格里拉大气本底站对大气CO2进行了初步观测.该站春、夏、秋、冬季CO2平均本底浓度分别为394.78×10-6(物质的量之比,下同)、386.82×10-6、386.46×10-6和390.74×10-6.全年浓度在4—5月最高,7月份最低,全年月均值振幅约12.22×10-6.四季浓度日平均高值出现在上午7∶00左右,最低值出现在14∶00—17∶00.日变化振幅在冬季最小,夏季最大,分别为1.51×10-6和21.82×10-6.四季西南来向的地面风对CO2浓度均有明显的降低作用.通过四季每日整点后向轨迹聚类计算,结合浓度资料分析发现,该站春、夏、秋季来自于西南方向的气团降低了观测的CO2浓度,而在冬季未起到明显的降低作用,主要因该站局地植被生态系统排放减少所致.
We carried out a downscaling treatment over China using the CarbonTracker numerical model,which was applied using double grid nesting technology(3°×2°over the whole globe,1°×1°over China),simulating and analyzing atmospheric CO2concentrations over 10 recent years(2000–2009).The simulation results agreed very well with observed data from four background atmospheric monitoring stations in China(The periods for which the simulation results and observed values be compared were January2000 to December 2009 for the WLG station and June 2006 to December 2009 for the SDZ,LFS,and LAN stations),giving correlation coefficients of>0.7.The high-resolution simulation data correlated slightly better than the low resolution simulation data with the observed data for three of the regions’atmospheric background stations.Further analysis of the annual,seasonal CO2concentration variations at the background stations showed that the CO2concentration increased each year over the study period,with an average annual increase of more than 5%,and annual increases of more than 7%at the Shangdianzi and Lin’an stations.Seasonal CO2variations were greater at the Longfengshan station than at the Shangdianzi or Lin’an stations.However,the CO2concentrations were higher at the Shangdianzi and Lin’an stations because they are greatly affected by human activities in the Jingjinji and Changjiang Delta economic zones.Spatial distribution in CO2concentrations and fluxes were higher in eastern than in western China.
CHENG YanLiAN XingQinYUN FangHuaZHOU LingXiLIU LiXinFANG ShuangXiXU Lin
