A computer model study of multiphase chemistry in the Arctic boundary layer during polar sunrise
A computer model study of multiphase chemistry in the Arctic boundary layer during polar sunrise
复制标题
DOI：
10.1029/2000jd900004
复制
发表时间：
2000-06
影响因子：
--
通讯作者：
Brian A. Michalowski;J. S. Francisco;Shao-Meng Li;L. Barrie;J. Bottenheim;P. Shepson
中科院分区：
文献类型：
--
作者：
Brian A. Michalowski;J. S. Francisco;Shao-Meng Li;L. Barrie;J. Bottenheim;P. Shepson
利用加拿大环境部开发的名为化学反应模拟系统(CREAMS)的基于PC的模拟程序，开发了北极卤素化学的多相化学盒模型。多相模型包括125个气相反应，19个光解反应，以及16个发生在悬浮气溶胶颗粒和雪的准液体成分中的水相反应。该模型模拟了气相和颗粒之间以及气相和积雪之间的物质传递。在400米边界层内的245K，对4月16日至4月24日期间的北极进行了模式模拟。完整的模型通过已知的气体和多相激活机制，模拟了从模型运行开始起5天内卤素催化的臭氧消耗。一个非常重要的模型反应是BrO+HCHO-HOBr+CHO，它对气相→和随后的凝聚相化学有很大的影响。当与将醛浓度维持在观察到的水平所必需的醛的雪堆流出相结合时，新的BRO化学反应通过雪堆中发生的化学作用对气相溴物种、粒子溴化物和氯原子的浓度产生重大影响。我们还发现，如果没有出现在积雪中的非均相卤素化学物质的存在，就不能模拟臭氧的消耗，并且臭氧的消耗速率受到HOBr到积雪中的传质速率的限制。
A multiphase chemical box model of Arctic halogen chemistry has been developed using a PC-based modeling program developed by Environment Canada called the Chemical Reactions Modeling System (CREAMS). The multiphase model contains 125 gas phase reactions, 19 photolysis reactions, and 16 aqueous reactions occurring in suspended aerosol particles and the quasi-liquid component of snow. The model simulates mass transfer of species between the gas phase and particles, and between the gas phase and the snowpack. Model simulations were conducted for the Arctic for the period April 16 to April 24 at 245 K within a 400 m boundary layer. The complete model simulates halogen-catalyzed ozone depletion within 5 days from the start of the model run, via known gas and heterogeneous phase activation mechanisms. A critically important model reaction is BrO + HCHO → HOBr + CHO, which has a substantial impact on gas phase HOBr, and subsequent condensed phase chemistry. When coupled with a necessary snowpack efflux of aldehydes, required to maintain the aldehyde concentrations at observed levels, the new BrO chemistry has a significant impact on the concentrations of gas phase bromine species, particle bromide, and chlorine atoms, through chemistry occurring in the snowpack. We also find that O3 depletion cannot be simulated without the presence of heterogeneous halogen chemistry occurring in the snowpack and that the rate of O3 depletion is limited by the mass transfer rate of HOBr to the snowpack.