The NO x dependence of bromine chemistry in the Arctic atmospheric boundary layer
The NO x dependence of bromine chemistry in the Arctic atmospheric boundary layer
复制标题
DOI：
10.5194/acp-15-10799-2015
复制
发表时间：
2015-09
影响因子：
6.3
通讯作者：
K. Custard;C. Thompson;K. Pratt;P. Shepson;J. Liao;L. G. Huey;J. Orlando;A. Weinheimer;E. Apel;S. Hall;F. Flocke;L. Mauldin;R. Hornbrook;D. Pöhler;S. General;J. Zielcke;W. Simpson;U. Platt;A. Fried;P. Weibring;B. Sive;K. Ullmann;C. Cantrell;D. Knapp;D. Montzka
中科院分区：
文献类型：
--
作者：
K. Custard;C. Thompson;K. Pratt;P. Shepson;J. Liao;L. G. Huey;J. Orlando;A. Weinheimer;E. Apel;S. Hall;F. Flocke;L. Mauldin;R. Hornbrook;D. Pöhler;S. General;J. Zielcke;W. Simpson;U. Platt;A. Fried;P. Weibring;B. Sive;K. Ullmann;C. Cantrell;D. Knapp;D. Montzka
抽象的。北极边界层氮氧化物(NOx=NO2+NO)是在阳光照耀的积雪中自然产生和释放的，在遥远的背景表层空气中的范围在10到100 pptv之间。这些氮氧化物对卤素和HOX(OH+HO2)等活性自由基的分配和循环有重要影响。然而，人们对当地人为NOx排放源对北极气相卤素化学的影响知之甚少，这一点很重要，因为这些排放会在环境NOx中引起很大的变化，从而导致当地化学变化。本研究采用零维光化学动力学模型，研究了北极地区春季大气中NOx对独特的卤素和HOx化学的影响。在2009年亚肯色州巴罗市的绿洲(海洋-大气-海冰-积雪)野外活动中获得的痕量气体测量被用来限制许多模型输入。我们发现，NOx的升高显著地阻碍了基于卤素自由基的气相臭氧的消耗，这是通过产生各种存储物种，包括HNO3、HO2NO2、过氧乙酰硝酸盐(PAN)、BrNO2、ClNO2以及BrO和HOBr的减少来实现的。在2012年溴、臭氧和汞实验(BROMEX)期间，通过在亚肯色州普拉德霍湾附近进行的测量，直接观察到人为NOx对溴的有效去除。因此，虽然可归因于气候变化的积雪覆盖的海冰的变化可能改变臭氧和汞消耗的分子卤素的可用性，但预测气候变化对极地大气化学的影响是复杂的，必须考虑到人为燃烧源的分布和强度变化的同时影响。北极地区尤其如此，由于石油和天然气开采和航运活动的增加，那里的NOx排放量预计将增加。
Abstract. Arctic boundary layer nitrogen oxides (NOx = NO2 + NO) are naturally produced in and released from the sunlit snowpack and range between 10 to 100 pptv in the remote background surface layer air. These nitrogen oxides have significant effects on the partitioning and cycling of reactive radicals such as halogens and HOx (OH + HO2). However, little is known about the impacts of local anthropogenic NOx emission sources on gas-phase halogen chemistry in the Arctic, and this is important because these emissions can induce large variability in ambient NOx and thus local chemistry. In this study, a zero-dimensional photochemical kinetics model was used to investigate the influence of NOx on the unique springtime halogen and HOx chemistry in the Arctic. Trace gas measurements obtained during the 2009 OASIS (Ocean – Atmosphere – Sea Ice – Snowpack) field campaign at Barrow, AK were used to constrain many model inputs. We find that elevated NOx significantly impedes gas-phase halogen radical-based depletion of ozone, through the production of a variety of reservoir species, including HNO3, HO2NO2, peroxyacetyl nitrate (PAN), BrNO2, ClNO2 and reductions in BrO and HOBr. The effective removal of BrO by anthropogenic NOx was directly observed from measurements conducted near Prudhoe Bay, AK during the 2012 Bromine, Ozone, and Mercury Experiment (BROMEX). Thus, while changes in snow-covered sea ice attributable to climate change may alter the availability of molecular halogens for ozone and Hg depletion, predicting the impact of climate change on polar atmospheric chemistry is complex and must take into account the simultaneous impact of changes in the distribution and intensity of anthropogenic combustion sources. This is especially true for the Arctic, where NOx emissions are expected to increase because of increasing oil and gas extraction and shipping activities.