Multiscale Modeling of Aerosol Indirect Effects on Decadal Timescales

气溶胶对云的影响作用于短期云上升气流的空间尺度（通常为100米- 100公里），但对气候的影响却持续数十年。这些对行星能量平衡的间接影响的多尺度性质对气候模式提出了特别的挑战，这导致间接影响的估计存在很大的不确定性。最难量化的气溶胶间接效应类型是那些气溶胶源受生态系统与气候的复杂相互作用控制的气溶胶，如海洋浮游植物和森林野火的气溶胶排放。该项目通过高级参数化、显式建模和多机构、多学科专家团队的观察相结合来解决这些挑战。气溶胶对层积云、浅积云和深积云的影响的高级参数化已经或正在由单独的资金开发，将被整合到一个与海洋耦合的多年代际模拟的共同框架中。将检查有气溶胶和没有气溶胶的模拟，以确定气溶胶间接效应对年代际气候变率的影响。这项评估将通过将太平洋海洋和大气条件的气候尺度变化与北美西海岸地区海洋-大气相互作用对气溶胶的敏感性以及随之而来的整个美国的大气条件联系起来来完成。(1)通过制定和试点针对服务不足的受众的非正式科学教育计划，促进教学、培训和学习；(2)扩大代表性不足的群体——在这种情况下是退休人员和老年人——对科学学习的参与；(3)通过与成熟的教育机构建立伙伴关系，加强教学基础设施；(4)通过演讲、同行评议出版物和网络广泛传播研究成果；(5)提高对气候科学和相关伦理问题的理解方面的社会效益。除了外展活动外，将至少有三名研究生，他们每人将接受三年的耦合地球系统建模培训，作为该项目的一部分。

Aerosol effects on clouds operate at spatial scales of short-lived cloud updrafts (typically 100 m- 100 km), yet exert a global effect on climate over multiple decades. The multiscale nature of these indirect effects on the planetary energy balance presents particular challenges to climate modeling, which has led to large uncertainties in estimates of indirect effects. The most difficult types of aerosol indirect effects to quantify are those for which the aerosol sources are controlled by complex interactions of ecosystems with climate, such as the aerosol emissions from ocean phytoplankton and from wildfires in forests. This project addresses these challenges through a combination of advanced parameterizations, explicit modeling, and observations with a multi-institutional,multi-disciplinary team of experts. Advanced parameterizations of aerosol effects on stratocumulus, shallow cumulus and deep cumulus clouds that have been or are being developed under separate funding will be brought together into a common framework for multidecadal simulations with coupling to the ocean. The simulations with and without aerosols will be examined to determine the influence of aerosol indirect effects on decadal climate variability. This evaluation will be accomplished by relating climate-scale changes in oceanic and atmospheric conditions over the Pacific to the sensitivities of regional ocean-atmosphere interactions to aerosols along the west coast of North America and consequent atmospheric conditions over the entire U.S. The broader educational impacts of the research will be realized through: (1) Promotion of teaching, training and learning through development and piloting of an informal science education program targeting an underserved audience; (2) Broadened participation of underrepresented groups--in this case, retired and elderly people--in scientific learning; (3) Enhancement of infrastructure for teaching through partnerships with an established educational organization; (4) Broad dissemination of results through presentations, peer-reviewed publications and via the web; and (5) Societal benefits in terms of improved understanding of climate science and the related ethical issues. In addition to outreach activities, there will be at least three graduate students who will each receive three years of training in coupled Earth system modeling as part of this project.