Year-round supraglacial lake monitoring in Northeast Greenland using synthetic aperture radar
| dc.contributor.author | Dean, Connor | |
| dc.contributor.supervisor | Scharien, Randall | |
| dc.date.accessioned | 2025-09-04T17:34:59Z | |
| dc.date.available | 2025-09-04T17:34:59Z | |
| dc.date.issued | 2025 | |
| dc.degree.department | Department of Geography | |
| dc.degree.level | Master of Science MSc | |
| dc.description.abstract | The Greenland Ice Sheet (GrIS) is one of largest contemporary contributors to global mean sea-level rise. Observations beginning in 1972 indicate its mass loss is accelerating and projected to continue throughout the century. Mitigating its impacts could require trillions of dollars, while the resulting higher seas may place hundreds of millions of people below the high-tide line by 2100. Mass loss of the GrIS results from surface mass balance (SMB) and dynamic ice discharge. Supraglacial lakes affect both processes by modulating albedo and surface melt water routing and contribute to enhanced basal sliding by delivering melt water to the bed during drainage events. Firstly, a novel C-band synthetic aperture radar (SAR) based methodology using Sentinel-1 and the RADARSAT Constellation Mission (RCM) data was developed to detect winter supraglacial lake drainage events at Nioghalvfjerdsbræ (79NG) and Zachariæ Isstrøm (ZI) in Northeast (NE) Greenland at high temporal resolutions. This enabled a decade long analysis of the spatiotemporal frequency of winter drainage events from 2014/2015 to 2023/2024 seasons. Winter drainage events occur during each winter season with substantial inter-seasonal variability. Approximately half of all winter drainage events (46 out of 90) were involved in cascade events. Short increases in ice velocity resulting from drainage events were observed, while there was little evidence for the ability of drainage events to drive seasonal or interannual ice velocity increases. These findings advance our understanding of winter supraglacial lake dynamics, a phase that remains far less studied than melt-season processes. Secondly, we conducted a melt season analysis to identify optimal SAR parameters for supraglacial lake detection in C- and L-band. Pairs of fully-polarimetric and compact-polarimetric images were compared and found that SAR parameters VV/HH and the linear polarization ratio (LPR) enabled enhanced capability for the detection of supraglacial lakes relative to single polarization channels. Additionally, L-band VV/HH and LPR exhibited a unique signature for snow and ice lids that bury portions of lakes, discriminating them from open water and surrounding ice sheet. | |
| dc.description.scholarlevel | Graduate | |
| dc.identifier.uri | https://hdl.handle.net/1828/22708 | |
| dc.language | English | eng |
| dc.language.iso | en | |
| dc.rights | Available to the World Wide Web | |
| dc.subject | Greendland Ice Sheet | |
| dc.subject | Supraglacial lakes | |
| dc.subject | Remote sensing | |
| dc.subject | Synthetic aperture radar | |
| dc.subject | Cryosphere | |
| dc.subject | Hydrology | |
| dc.subject | Climate change | |
| dc.subject | Glaciology | |
| dc.title | Year-round supraglacial lake monitoring in Northeast Greenland using synthetic aperture radar | |
| dc.type | Thesis |