Impacts of the Biosphere on Global Tropospheric Chemistry and Climate

这项研究工作将调查土地利用变化对大气成分的影响，主要关注从工业化前（1850年）到未来（2100年）的臭氧（O3）和二次有机气溶胶（SOA）。利用完全耦合的生物圈-大气模式系统（NCAR的社区地球系统模式，CESM）模拟生物源排放、对流层组成、沉积和反馈对土地利用、植被和人为排放变化的响应。当前一代的SOA处理方案将得到扩展，以处理大气老化以及由此导致的功能化和碎片化。新方案将根据实地观测进行测试，对各种约束不佳因素的敏感性将进行量化。将O3对植被的破坏影响纳入陆地模型，并评估O3对生物源性挥发性有机化合物（BVOC）排放的潜在直接影响。对历史土地利用变化影响的分析将主要集中在美国东南部，那里的温度趋势暂时归因于植被和SOA的变化。这部分调查将借鉴南方氧化剂和气溶胶研究（SOAS）实地活动的结果，如果它得到资助的话。这项工作将有助于解决控制对流层臭氧和SOA浓度的突出因素。该研究将解决与了解未来空气质量的主要驱动因素及其对公众健康的相关影响有关的社会和政策问题。此外，这项工作将开发下一代方案，明确评估SOA在全局模型中的一般应用的大气老化。这项研究将支持并有助于研究生和博士后的教育。研究生水平的课程将进一步探索生物圈与大气在课堂环境中的相互作用。最后，研究活动将与波士顿科学博物馆的外展项目联系起来，在该项目中，本科生暑期将在博物馆的当代科学和技术展览中工作，将大气化学研究带给公众。

This research effort will investigate impacts of land use change on atmospheric composition with a primary focus on ozone (O3) and secondary organic aerosol (SOA) from pre-industrial (1850) to future conditions (2100). The responses of biogenic emissions, tropospheric composition, deposition, and feedbacks to changes in land use, vegetation, and anthropogenic emissions will be simulated with fully coupled biosphere-atmosphere model system (NCAR's Community Earth System Model, CESM). The current-generation scheme for SOA processing will be expanded to treat atmospheric aging and resulting functionalization and fragmentation. The new scheme will be tested against field observations and sensitivities to various poorly constrained factors will be quantified. The impacts of O3 damage to vegetation will be incorporated into the land model and the potential direct impacts of O3 on biogenic volatile organic compound (BVOC) emissions will be evaluated. Analysis of the impacts of historical land use change will focus primarily on the southeastern United States (US) where temperature trends have been tentatively attributed to changing vegetation and SOA. This part of the investigation will draw on results of the Southern Oxidant and Aerosol Study (SOAS) field campaign should it be funded. This effort will help resolve outstanding factors that control tropospheric concentrations of O3 and SOA.The research will address social- and policy-related issues relevant to understanding major drivers of future air quality and associated impacts on public health. In addition, this effort will develop a next-generation scheme that explicitly evaluates the atmospheric aging of SOA for general application in global models. The research will support and contribute to the education of a graduate student and postdoctoral fellow. A graduate-level class will be developed to further explore biosphere-atmosphere interactions in the classroom setting. Finally, the research activities will be tied to an outreach project through the Boston Museum of Science in which undergraduate summer students will work on the museum's Current Science and Technology exhibits to bring atmospheric chemistry research to the public.