我们基于“自上而下”的方法和卫星观测数据反演了长三角地区2016年1月、4月、7月和10月NO_X排放。结果显示“自上而下”NO_X排放为260 Gg/月，比“自下而上”排放低24%。基于“自上而下”排放的NO₂模拟结果要明显好于“自下而上”排放的结果，暗示基于非线性反演方法和卫星观测可以优化NO_X排放。基于O₃和SNA的敏感性分析实验，发现VOCs排放对减缓长三角O₃污染十分重要，而减少NH₃排放对控制该地区冬季的SNA污染最有效。

   祝贺杨杨！

  We developed a “top-down” methodology combining the inversed chemistry transport modeling and satellite-derived tropospheric vertical column of NO₂, and estimated the NO_X emissions of Yangtze River Delta (YRD) region at a horizontal resolution of 9 km for January, April, July and October 2016. The top-down estimates of NO_X emissions were calculated at 260.0 Gg/month, 24% less than the bottom-up one. The model performance based on top-down estimate was much better, suggesting the improvement of NO_X emission estimation with the nonlinear inversed modeling and satellite observation constraint. The sensitivity analysis of O₃ and SNA formation implied that VOCs control played a crucial role on O₃ pollution abatement and that reducing NH₃ emissions was the most effective way to alleviate SNA pollution for YRD in winter.

  Congratulations to Yang Yang!

 The bottom-up and top-down estimates of NO_X emissions by month for the YRD region in 2016.