Bromide in Snow in the Sea Ice Zone

极地纬度的一系列化学和微物理途径，包括春季(对流层)臭氧消耗、汞的氧化途径和云凝结核(CCN)的产生，导致云层和伴随而来的地表能量收支的变化，被援引为依赖于海冰中形成的卤素气体的排放。气候变暖导致海冰面积减少，造成这些不完全已知的地表-大气反馈和相互作用的改变的前景，需要在实验室研究和实地运动中确认机制细节。一个这样的机制问题是，在随后的强风将其作为气溶胶部分移动到大气之前，富含溴(溴和溴)的雪是如何在海冰中迁移或形成的。一旦升空，它可能会与臭氧和其他大气物种发生反应。达特茅斯大学的研究人员将从海冰表面、自由飘动的积雪和罗斯海伯德角的海冰岩芯中收集雪。随后将使用一系列光谱、显微分析和显微结构方法来确定溴在海冰中的分布梯度，以便阐明海冰如何首先形成溴物种，然后将溴物种释放到极地大气边界层。

A range of chemical and microphysical pathways in polar latitudes, including spring time (tropospheric) ozone depletion, oxidative pathways for mercury, and cloud condensation nuclei (CCN) production leading to changes in the cloud cover and attendant surface energy budgets, have been invoked as being dependent upon the emission of halogen gases formed in sea-ice. The prospects for climate warming induced reductions in sea ice extent causing alteration of these incompletely known surface-atmospheric feedbacks and interactions requires confirmation of mechanistic details in both laboratory studies and field campaigns. One such mechanistic question is how bromine (BrO and Br) enriched snow migrates or is formed through processes in sea-ice, prior to its subsequent mobilization as an aerosol fraction into the atmosphere by strong winds. Once aloft, it may react with ozone and other atmospheric species. Dartmouth researchers will collect snow from the surface of sea ice, from freely blowing snow and in sea-ice cores from Cape Byrd, Ross Sea. A range of spectroscopic, microanalytic and and microstructural approaches will be subsequently used to determine the Br distribution gradients through sea-ice, in order to shed light on how sea-ice first forms and then releases bromine species into the polar atmospheric boundary layer.