Polar boundary layer bromine explosion and ozone depletion events in the chemistry–climate model EMAC v2.52: implementation and evaluation of AirSnow algorithm
Polar boundary layer bromine explosion and ozone depletion events in the chemistry–climate model EMAC v2.52: implementation and evaluation of AirSnow algorithm
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DOI：
10.5194/gmd-11-1115-2018
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发表时间：
2017-07
影响因子：
5.1
通讯作者：
S. Falk;B. Sinnhuber
中科院分区：
文献类型：
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作者：
S. Falk;B. Sinnhuber
抽象的。春季极地边界层臭氧消耗事件（ODEs）频繁发生。它们与溴的边界层增强事件有关。因此，通过现场观测、地面和机载遥感以及卫星观测到BrO的边界层体积混合比（VMR）和垂直柱密度（VCD）增加。这些所谓的溴爆炸（BE）事件被认为是高纬度对流层BrO的来源，迄今为止在全球模式中被低估。我们根据丰田等人（2011年）的方案，在全球化学气候模型EMAC（ECHAM/MESSy大气化学）中对海冰和积雪覆盖的表面上的溴释放和再循环进行了处理。在该方案中，干沉积通量的HBr，HOBr，和BrNO 3在冰雪覆盖的表面被回收到溴通量。此外，O3的干沉积，取决于温度和阳光，触发了与第一年海冰相关的表面的Br 2释放。这种相对简单的方法再现了在北极和南极观测到的溴含量增加的许多方面以及与之相关的边界层臭氧几乎完全耗尽的情况。我们提出的第一个结果，从我们的全球模式研究延伸到一个完整的年度周期，包括与全球臭氧监测实验（GOME）卫星溴VCD和地面臭氧观测的比较。
Abstract. Ozone depletion events (ODEs) in the polar boundary layer have been observed frequently during springtime. They are related to events of boundary layer enhancement of bromine. Consequently, increased amounts of boundary layer volume mixing ratio (VMR) and vertical column densities (VCDs) of BrO have been observed by in situ observation, ground-based as well as airborne remote sensing, and from satellites. These so-called bromine explosion (BE) events have been discussed serving as a source of tropospheric BrO at high latitudes, which has been underestimated in global models so far. We have implemented a treatment of bromine release and recycling on sea-ice- and snow-covered surfaces in the global chemistry–climate model EMAC (ECHAM/MESSy Atmospheric Chemistry) based on the scheme of Toyota et al. ( 2011 ) . In this scheme, dry deposition fluxes of HBr , HOBr , and BrNO3 over ice- and snow-covered surfaces are recycled into Br2 fluxes. In addition, dry deposition of O3 , dependent on temperature and sunlight, triggers a Br2 release from surfaces associated with first-year sea ice. Many aspects of observed bromine enhancements and associated episodes of near-complete depletion of boundary layer ozone, both in the Arctic and in the Antarctic, are reproduced by this relatively simple approach. We present first results from our global model studies extending over a full annual cycle, including comparisons with Global Ozone Monitoring Experiment (GOME) satellite BrO VCDs and surface ozone observations.