寒冷地区活性氯化学对 HONO 生消的机理研究

Nitrous acid（HONO），a significant precursor to hydroxyl radicals，is pivotal in atmospheric chemistry，yet its sources and formation mechanisms remain elusive. The chemical mechanism embedded in the CAMx model predominantly accounts for the gas-phase generation of HONO，which often resulted in an underestimation of simulated HONO levels. The Northeast region of China with extended period of ice and snow cover，provided an abundance of air-snow interfaces conducive to heterogeneous chemical reactions. This study adopted the anthropogenic chlorine emission inventory and integrated it with the HONO related heterogeneous reactions. Utilizing the CAMx model，we investigated the influence of active chlorine on HONO production and consumption under the ice and snow conditions of Northeast China，as well as its potential contribution to secondary pollution. Our results indicated that anthropogenic chlorine emissions were particularly concentrated in the region of Harbin-Changchun during winter，predominantly from the incineration of straw and coal-burned heating. The incorporation of 11 new heterogeneous reactions into the CAMx model notably enhanced the simulation's accuracies of particulate matters and ozone. A sensitivity analysis of the model underscored that the heterogeneous interaction between ice and snow surface-adsorbed chloride（HCl）and HONO also was a significant HONO sink. These findings offered novel insights into the mechanisms of regional HONO production and consumption under ice and snow conditions.