Collaborative Research: NSFGEO-NERC: Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit: Measurements along Lagrangian Transects

该项目由美国国家科学基金会地球科学理事会（NSF/GEO）和英国国家环境研究委员会（UKRI/NERC）通过NSF/GEO-NERC牵头机构协议共同资助。该协议允许美国/英国提交一份联合提案，并由其调查员拥有最大比例预算的机构进行同行评审。在成功地共同确定一项奖励后，每个机构为预算的比例和与其自己的建议和工作组成部分有关的调查人员提供资金。该研究项目延续了一项为期11年的野外实验，名为“峰顶能量、云、大气状态和降水综合表征”（ICECAPS），并增加了沿拉格朗日样带（ICECAPS- melt）的测量。该项目是一项国际合作项目，自2010年以来一直在格陵兰峰顶站操作地面仪器，对大气进行观测，以促进对格陵兰冰盖上云特性、辐射和表面能以及降水过程的了解。由于北极气候的快速变化，格陵兰岛正在经历变化，因此进行这些观测是一个重要的时机。目前的项目继续在顶峰站进行观测，并沿着横断面扩展测量到格陵兰岛的另一个重要区域，称为渗透区。在这个区域，融化的水在地表产生，在那里它可以渗透到雪中，然后重新冻结。这就形成了冰层，使额外的融水水平而不是垂直移动。了解这些过程非常重要，因为格陵兰冰盖的融化是全球海平面上升的一个重要因素，预计这将在下个世纪对人类产生重大影响。这个新的ICECAPS- melt项目通过建立一个新的移动观测站来测量格陵兰冰盖表面质量和能量收支参数，从而补充了ICECAPS峰会观测站。这个天文台采用了一种新颖的无人值守的自主操作方法，它支持的仪器需要适度的功率和互联网带宽，但与山顶站的操作非常相似。新的天文台测量地表质量和能量收支参数，包括降水、云特性、辐射和湍流通量、近地表气象学、地下温度和结构。为此，ICECAPS-MELT团队部署了降水雷达、云激光雷达、微波辐射计、探地雷达和自动地面通量站，这些设备在正常情况下消耗约500瓦的功率。该项目将对这个新天文台和正在进行的首脑会议测量之间的表面质量和能量预算参数如何在空间和时间上共同变化产生新的见解。轨迹分析跟踪了气流上升到格陵兰冰盖并经过两个观测点时的变化。移动观测站将在连续的夏季部署在干雪区的高峰站和渗透区的DYE-2站。如果这个项目成功，这些观测站的网络将被提议用于未来在格陵兰西南部的部署，这将为大气特性和过程如何在空间和时间上与格陵兰冰盖的表面和地下条件相耦合提供新的见解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This is a project that is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (UKRI/NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own proposals and component of the work.This research project continues an 11-year field experiment called the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit (ICECAPS) and adds measurements along Lagrangian transects (ICECAPS-MELT). The project is an international collaboration that has been operating ground-based instruments at Summit Station in Greenland since 2010, taking observations of the atmosphere to advance understanding of cloud properties, radiation and surface energy, and precipitation processes over the Greenland Ice Sheet. It is an important time to make these observations because Greenland is undergoing changes due to rapid shifts in Arctic climate. The current project continues the observations made at Summit Station and expands measurements along transects to another important region of Greenland called the percolation zone. In this zone, melt water is generated at the surface, where it can percolate down into the snow and then refreeze. This creates ice layers that can cause additional melt water to move horizontally rather than vertically. It is important to understand these processes because melting of the Greenland Ice Sheet is a significant contributor to global sea level, which is predicted to impact humans significantly over the next century.This new ICECAPS-MELT project complements the ICECAPS Summit observatory by building a new mobile observatory for measuring parameters of the surface mass and energy budgets of the Greenland Ice Sheet. This observatory uses a novel approach for unattended, autonomous operation by supporting instruments that require moderate power and internet bandwidth yet are quite like those operated at Summit Station. The new observatory measures surface mass and energy budget parameters, including precipitation, cloud properties, radiative and turbulent fluxes, near-surface meteorology, and subsurface temperatures and structure. To do this, the ICECAPS-MELT team deploys a precipitation radar, a cloud lidar, a microwave radiometer, a ground-penetrating radar, and an automated surface flux station, which consume approximately 500 W of power under normal conditions. The project will lead to new insights into how parameters of the surface mass and energy budgets co-vary in space and time between this new observatory and the ongoing measurements at Summit. Trajectory analyses track the changes in air parcels as they ascend the Greenland Ice Sheet and pass over the two observational sites. The mobile observatory will be deployed in successive summers at Summit Station in the dry-snow zone and at the DYE-2 station in the percolation zone. If this project is successful, a network of these observatories will be proposed for future deployment in southwestern Greenland, which will provide new insights into how atmospheric properties and processes are coupled both spatially and temporally to the ice sheet’s surface and subsurface conditions over Greenland.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.