Multiscale Modeling of Aerosol Indirect Effects on Decadal Timescales

气溶胶对云的影响作用于短暂的云上升气流的空间尺度（通常为100米至100公里），但在数十年内对气候产生全球影响。这些对行星能量平衡的间接影响的多尺度性质对气候建模提出了特别的挑战，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影响类型是气溶胶来源受生态系统与气候的复杂相互作用控制的气溶胶，例如海洋浮游植物和森林野火的气溶胶排放。 该项目通过结合先进的参数化、明确的建模和多机构、多学科专家团队的观察来解决这些挑战。已经或正在单独供资开发的气溶胶对层积云、浅积云和深积云影响的先进参数化将被纳入一个共同框架，用于与海洋耦合的数十年模拟。有和没有气溶胶的模拟将被检查，以确定气溶胶的间接效应对十年气候变率的影响。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沿着区域海洋-大气相互作用对气溶胶的敏感性以及随后整个美国的大气条件相关联来完成。（1）通过制定和试行针对服务不足的受众的非正式科学教育方案，促进教学、培训和学习;（2）扩大代表性不足的群体-这里指退休人员和老年人-参与科学学习;（3）通过与现有教育组织建立伙伴关系，加强教学基础设施;（4）通过演讲、同行评议的出版物和网络广泛传播成果;（5）在提高对气候科学和相关伦理问题的理解方面的社会效益。除了推广活动外，作为该项目的一部分，将至少有三名研究生每人接受三年的耦合地球系统建模培训。

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.