Multiscale Modeling of Aerosol Indirect Effects on Decadal Timescales

对云的气溶胶效应在短暂的云上升气流(通常为100米-100公里)的空间尺度上运行，但在几十年内对全球气候产生影响。这些对行星能量平衡的间接影响的多尺度性质给气候模拟带来了特别的挑战，这导致间接影响的估计有很大的不确定性。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类型，例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。在单独供资下已经开发或正在开发的层积云、浅积云和深积云上的气溶胶效应的高级参数化将合并成一个与海洋相耦合的数十年模拟的共同框架。将审查有无气溶胶的模拟，以确定气溶胶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地区海洋和大气条件的气候尺度变化与北美西海岸的区域海洋-大气相互作用对整个美国的大气条件的敏感性相联系来完成。这项研究的更广泛的教育影响将通过以下方式实现：(1)通过开发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)扩大代表不足的群体--在这种情况下是退休人员和老年人--在科学学习中的参与；(3)通过与现有教育组织的伙伴关系，加强教学基础设施；(4)通过专题介绍、同行评议出版物和网络广泛传播成果；(5)增进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，还将有至少三名研究生，作为该项目的一部分，他们每人将接受为期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.