Collaborative Research: Characterizing the Roles of Atmospheric Structure and Clouds on the Radiation and Precipitation Budgets at Summit, Greenland

提供了资金，以表征大气状态，云的性质，辐射和降水之间的相互作用在顶峰，格陵兰岛。目的是研究一些重要的与云有关的过程，这些过程如何与北极气候系统相互作用，以及它们对地表能量和质量收支的影响。具体的焦点将包括：1)导致北极层状云长期存在的低云持续机制，它与大气结构和地表能量收支有强烈的相互作用；2)云相划分，它决定了云的微物理组成，并最终决定了云对大气辐射和水文循环的影响；3)降水划分，了解峰顶降水的不同模式及其对地表总积累的影响。为了解决这些问题，该项目将利用部署在Summit的一套地面遥感器的详细观测数据，这是NSF/ aon资助的ICECAPS项目的一部分，并结合星载有源遥感器的数据。高分辨率数值模拟还将用于研究许多精细尺度的云过程及其中尺度影响。在格陵兰冰盖上的这些研究也将在北极其他地点进行的类似测量和模式研究的背景下加以考虑，以便了解在首脑会议上以及在更一般意义上整个北极地区的这些重要过程。大气中的水蒸气、云和降水极大地影响了北极的地表能量和冰冻圈质量平衡，并对这些平衡的大部分变化负有责任。据认为，最近北极海冰的快速融化可能部分是由云层覆盖和辐射的变化所驱动的。众所周知，与云相关的过程和反馈是全球气候模式不确定性的最大来源之一，这些缺点已在北极的模式模拟中得到明确确认。因此，该项目的结果将提高我们对北极云过程的理解，并将其纳入气候模型，这反过来将提高可预测性。由于本研究的广泛影响，该项目将为参与大学的四名新研究生提供重要的数据分析和整合经验。此外，本研究的数据和结果将整合到高中学生和教师的本科课程和暑期研讨会中。

Funds are provided to characterize the interactions among the atmospheric state, cloud properties, radiation, and precipitation at Summit, Greenland. The objective is to investigate a number of important cloud-related processes, how these interact with the Arctic climate system, and their impact on the surface energy and mass budgets. Specific foci will include:1) Low-cloud persistence mechanisms that lead to long-lived Arctic stratiform clouds, which interact strongly with the atmospheric structure and surface energy budget;2) Cloud-phase partitioning, which determines the cloud microphysical composition and, ultimately, the effects that clouds have on atmospheric radiation and the hydrologic cycle; and3) Precipitation partitioning, in order to understand the different modes of precipitation at Summit and how these impact the total surface accumulation.To address these topics, this project will utilize detailed observations from a suite of ground-based remote sensors deployed at Summit as part of the NSF/AON-funded ICECAPS project in combination with data from satellite-borne active remote sensors. High-resolution numerical modeling will also be used to investigate many of the fine-scale cloud processes and their mesoscale influences. These studies over the Greenland Ice Sheet will also be considered within the context of similar measurements and model studies made at other Arctic locations in order to understand these important processes over Summit and, in a more general sense, across the Arctic.Atmospheric water vapor, clouds, and precipitation greatly affect the surface energy and cryospheric mass balances in the Arctic, and are responsible for much of the variability in these balances. It is thought that recent rapid melting of Arctic sea ice may be driven, in part, by changes in cloud cover and radiation. Cloud-related processes and feedbacks are known to be one of the greatest sources of uncertainty in global climate models, and these shortcomings have been clearly identified in model simulations over the Arctic. Thus, the results of this project should improve our understanding of Arctic cloud processes and their inclusion in climate models, which, in turn, will improve predictability. As broader impacts of this research, the project will provide important data analysis and integration experience for four new graduate students at the participating universities. In addition, data and results from this study will be integrated into undergraduate coursework and summer workshops for high school students and teachers.