The Greenland GPS Network (GNET): Geodetic constraints on climate cycles, climate change and ice mass balance in Greenland

这项为期一年的合同将支持格陵兰GPS网络（GNET）的初始维护和升级，该网络最初是在2007-2009年国际极地年期间安装的。2011年夏季的维护和升级活动将集中在格陵兰东南海岸和巴芬湾西岸的设施上。知识价值：GNET的主要目的是研究气候周期和气候变化引起的冰盖物质平衡变化，并为冰川均衡调整模式提供观测约束，该模式通常被称为冰后反弹（PGR），为GRACE（重力恢复和气候实验）卫星任务和任何后续任务提供关键的“PGR校正”。目标是以尽可能高的空间分辨率获得一组一致的重力、位移和冰块历史。GNET还将通过在所有GPS（全球定位系统）站点生成可降水量（PW，即综合水汽）解决方案，提供地表质量平衡（SMB）的气象估计，这些解决方案可以利用数值天气模式（NWM）加以吸收和利用。来自高分辨率NWMs的地表大气压力场将用于校正GPS时间序列的大气载荷效应，从而分离出与冰块季节性变化相关的位移周期。更广泛的影响：GNET是由俄亥俄州立大学领导的美国团队与丹麦和卢森堡的国际合作伙伴之间的国际合作。预计GNET将有助于了解气候和海平面变化的全球重大问题，并将能够在突然发生的几周内发现失控或灾难性冰损失的发生。GNET和NWM社区之间的合作可能对一般气象产品产生重大影响。还预期全球大气信息网将有助于极地电离层的研究，并能与格陵兰岛和加拿大北部现有的空间物理网络和设施协同工作。GNET将用作一般定位基础设施，用于测量飞机的运动学定位，嵌入冰流中的GPS漫游车等。GNET正在成为一种多用途仪器或设施，以及一个具体的研究项目。

This 1-year award will support initial maintenance and upgrade of the Greenland GPS Network (GNET) that was originally installed during International Polar Year 2007-2009. Maintenance and upgrade activities in summer 2011 will focus on installations along the southeast coast of Greenland and along the west coast facing Baffin Bay.Intellectual Merit: The primary purpose of GNET is to study changes in ice sheet mass balance produced by climate cycles and climate change, and to provide observational constraints on models of glacial isostatic adjustment, often referred to as postglacial rebound (PGR), which provide the crucial 'PGR correction' for the GRACE (Gravity Recovery and Climate Experiment) satellite mission and any follow-on missions. The goal is to achieve a consistent set of gravity, displacement and ice mass histories with the highest possible spatial resolution. GNET will also contribute meteorological estimates of surface mass balance (SMB) by generating precipitable water (PW, i.e., integrated water vapor) solutions at all GPS (Global Positioning System) stations that can be assimilated and exploited using numerical weather models (NWM). Surface atmospheric pressure fields from high resolution NWMs will be used to correct the GPS time series for atmospheric loading effects, thereby isolating the displacement cycles associated with seasonal changes in ice mass. Broader Impacts: GNET is an international collaboration between a US team, led by Ohio State University, and international partners in Denmark and Luxembourg. It is expected that GNET will contribute to understanding of the globally significant issues of climate and sea level change, and will be able to detect the onset of runaway or catastrophic ice loss within weeks of a sudden onset. A collaboration between GNET and the NWM community could have a significant impact on general meteorological products. It is also expected that GNET will contribute to studies of the polar ionosphere, and can synergize with existing space physics networks and facilities in Greenland and northern Canada. GNET will be used as a general positioning infrastructure, for kinematic positioning of survey aircraft, GPS rovers embedded in ice flows, etc. GNET is becoming a multiple use instrument or facility, as well as a specific research project.