Collaborative Research: Inhibition of Snowfall by Pollution Aerosols

知识价值：这项研究将促进对气溶胶污染在改变冬季地形降水中的潜在作用的理解。要解决的一个关键问题是气溶胶污染对云的影响如何被各种天气状况、云类型和云内过冷水的数量所改变。根据以前的建模结果，预计含有较多过冷水的云（如科罗拉多州圣胡安山脉上空的典型云）更容易受到气溶胶污染的影响。这种潜在响应的调制将通过风暴峰值实验室（SPL）的时间序列测量和通过科罗拉多州圣胡安山脉的更分布式测量以及模式模拟来解决。变革性研究的潜力：这项研究有可能修订气溶胶对冬季地形降水影响的传统理论。先前的工作表明，污染气溶胶浓度的增加导致从地形云中落下的降水显著减少。首席调查员在科罗拉多州帕克山脉进行的进一步研究表明，气溶胶污染也可能重新分配地形降水和随后在邻近河流流域之间的径流。根据这一观点，总降水量可能会有所减少，但气溶胶引起的降水位置转移占主导地位。这两种潜在影响的相对贡献将在新的研究中进一步探讨。考虑到更长的时间周期（即整个冬季），应得出更有力的结论，并改进污染气溶胶影响的区域气候学。更广泛的影响：这项工作具有重要的人口和经济意义。如果污染气溶胶确实系统性地减少了山区降雪，那么美国西部地区的不断发展将反过来减少可用的积雪来源的水资源，而这些水资源是维持这种人口增长所必需的，因此需要采取策略来尽量减少这种影响。在本研究的野外部分，SPL的教育和推广活动将包括由首席研究员领导的为期三天的研究生水平的中尺度建模课程，由威斯康星大学合作者领导的为期一周的山地气象学研究生/本科生课程，以及。由沙漠研究所提供的研究生野外气象学课程，侧重于SPL独特的观测能力。该实验室位于蒸汽船滑雪胜地的顶峰，也为公众提供了大量的活动机会，这项资助下的主要研究人员将为公众开放房屋，并创建一个更永久的户外展示，描述该项目下所做的工作。

Intellectual Merit: This research will advance understanding of the potential role of aerosol pollution in modifying wintertime orographic precipitation. A key issue to be addressed is how the influence of aerosol pollution upon clouds may be altered by various synoptic weather regimes, cloud types, and amounts of supercooled water within these clouds. Based on previous modeling results, it is anticipated that clouds with higher amounts of supercooled water (such as those typically found over the San Juan Mountains of Colorado) are more susceptible to impacts by aerosol pollution. The modulation of this potential response will be addressed both temporally via time-series measurements at the Storm Peak Laboratory (SPL) and spatially through more distributed measurements over the San Juan Mountains of Colorado and through model simulations.Potential for Transformative Research: This investigation has the potential to revise traditional theories of aerosol-induced impacts on wintertime orographic precipitation. Prior work has suggested that increased pollution aerosol concentrations lead to a significant reduction in precipitation falling from orographic clouds. Further studies by the Principal Investigators conducted in the Park Range mountains of Colorado suggest that aerosol pollution may also redistribute orographic precipitation and subsequent runoff among adjacent river basins. In this view, some reduction of total precipitation may occur but aerosol-induced shifts in the location of precipitation predominate. The relative contributions of these two potential influences will be further explored in this new study. Consideration of longer time periods (i.e., a full winter season) should lead to more robust conclusions, as well as an improved regional climatology of pollution aerosol influences.Broader Impacts: This work has significant demographic and economic implications. If pollution aerosols are indeed systematically reducing mountain snowfall, increased development across the western U.S. will in turn reduce available snowpack-derived water resources needed to sustain such population growth and require strategies to minimize such impacts. Education and outreach activities at SPL during the field component of this study will include a three-day graduate level mesoscale modeling class led by the Principal Investigator, a week-long graduate/undergraduate class in mountain meteorology led by a University of Wisconsin collaborator, and. a graduate field meteorology class offered through the Desert Research Institute focusing on SPL's unique observational capabilities. The location of the laboratory at the summit of the Steamboat Ski Resort also affords considerable public access to its full range of activities, and the Principal Investigators supported under this grant will conduct open houses for the public and create a more permanent outdoor display describing work being done under this project.