Mapping and measuring glacier mass balance: developing a best practice approach for understanding glacier change

绘制和测量冰川质量平衡：开发了解冰川变化的最佳实践方法

• 批准号: 2772881
• 金额: --
• 依托单位: University of Aberdeen
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2772881
• 关键词: Mapping; measuring; glacier; mass; balance

Background and Rationale Understanding the current and future "health" of glaciers and icecaps globally is an important scientific goal in our warming climate. Glaciers and ice caps have been, and will be for several decades to come, important contributors to sea level rise. Additionally, in many countries they are vital to the provision of water resources, especially in the dry season, which is used for human consumption, agriculture, industry and hydropower. While in other countries they are also significant for tourism and recreation, at least at the local and regional level. Large banks of satellite imagery are now freely available and are now being widely used to assess the state of glaciers globally, via repeat surveys, DEM differencing and end-of-season snowline (ESS) mapping. This approach is especially appealing as it can be implemented globally and automation methods applied to image classification have the potential to reduce labour intensity of the work even offering the potential for generation of annual or even sub-annual timeseries.Databases such as GLIMS (Global Land Ice Measurements from Space) and RGI (Randolph Glacier Inventory) , allow large scale assessments of the mass balance of glaciers and ice caps to be undertaken using the geodetic method (GDM), which does not require on-the-ground physical measurements. This is very appealing for remote and difficult to access glaciers, for example in the arctic and high mountains. Additionally, archives of satellite imagery allow for the generation of time series of ESS offering great potential for contextualising ongoing change. The other approach to mass balance assessment is the glaciological method (GLM), which is labour intensive, difficult and potentially dangerous and essentially excludes some glaciers in the remote regions of the planet. Repeat measurements are undertaken at the end of the winter and summer which importantly allows the determination of seasonal and annual balances. The World Glacier Monitoring Service (WGMS) holds the largest data set of GLM glacier mass balance time series. The data can be used to determine annual ELAs and to provide both error estimation and corrections for ESS measurements and this represents the first aim of this project: 1 - to undertake a systematic mapping of ESS on glaciers with GLM mass balance records, determine the potential error in comparison to measured ELAs and determine corrections. It is anticipated that there will be significant regional differences the short time series generated from satellite imagery may then be more susceptible to error in areas with high mass balance amplitudes, but less so in regions with low mass balance amplitudes. The second aim of the project, 2 - will be to identify regions where the error between ESS and measured ELAs are most robust, determined from 1. Within these regions, glaciers which have no measured ELAs will be mapped to generate a timeseries of ESS. Depending on time available these analyses will be extended to as many regions as possible, hopefully to global coverage. The timeseries of ESS will provide the basis for a region by region assessment of glacier mass balance change extended as far back as the satellite image record will allow.

背景和理由理解全球冰川和冰川的当前和未来的“健康”是我们温暖气候的重要科学目标。冰川和冰盖已经过去了几十年，这是海平面上升的重要贡献者。此外，在许多国家，它们对于提供水资源至关重要，尤其是在干旱季节，该季节用于人类消费，农业，工业和水力发电。在其他国家，至少在地方和地区一级，它们对旅游和娱乐也很重要。现在可以免费获得大量的卫星图像，并且通过重复调查，DEM差异和季节结束雪线（ESS）映射广泛用于评估冰川状态。这种方法特别吸引人，因为它可以在全球范围内实施，并且适用于图像分类的自动化方法有可能减少工作的劳动强度，即使为年度或什至少年的时间表提供了产生潜力的潜力。 （GDM），不需要地面物理测量。对于远程且难以进入冰川，例如在北极和高山中，这非常吸引人。此外，卫星图像的档案范围可以产生ESS的时间序列，从而为不断变化提供了巨大的潜力。质量平衡评估的另一种方法是冰川学方法（GLM），该方法是劳动密集型，困难且潜在危险的，本质上排除了地球偏远地区的某些冰川。重复测量是在冬季和夏季结束时进行的，这重要的是确定季节性和年平衡。世界冰川监测服务（WGMS）拥有GLM冰川质量平衡时间序列最大的数据集。数据可用于确定年度ELA，并为ESS测量提供误差估计和校正，这代表了该项目的第一个目的：1-使用GLM质量平衡记录对ESS进行系统映射，请确定与测量ELA相比的潜在误差并确定校正。预计将存在重大的区域差异，因此从卫星图像产生的短时间序列可能会更容易在质量平衡幅度较高的区域中出现错误，但在低质量平衡幅度幅度较低的区域中却较少。项目2的第二个目标是确定ESS和测得的ELA之间的误差最强大的区域，从1个确定。在这些区域中，将绘制未测量ELA的冰川以生成ESS的时间。根据可用的时间，这些分析将扩展到尽可能多的地区，希望将其扩展到全球覆盖范围。 ESS的时间表将根据冰川质量平衡变化的区域评估为卫星图像记录所允许的区域提供基础。