Pan-Arctic detection of river ice breakup and freeze-up timing on rivers wider than 150m using MODIS imagery from 2000-2019
Abstract
River ice on and off timing is responsive to changes in air temperature and is therefore a sentinel system for understanding Arctic climate change. Shifts in ice timing and duration are important to study because they impact wintertime transportation and sediment and nutrient transport in Arctic riverine systems. Previous studies of pan-Arctic river ice breakup and freeze-up use point-based ground observations to identify spatial and temporal trends. However, ground-based observations have a sampling bias towards rivers in populated areas and point-based observations do not adequately describe variability in trends within entire river systems. Using daily Moderate Resolution Imaging Spectroradiometer imagery and a multi-thresholding method previously applied to Alaskan rivers, we detect ice breakup and freeze-up timing on all rivers wider than 150m above 60°N (total river length: ~ 115,000km) from 2000 through the 2019 breakup season. We identify regions of the pan-Arctic that have experienced heightened changes in ice timing and variability over the past twenty years and compare yearly ice timing to teleconnections including the Pacific Decadal Oscillation, the Southern Oscillation Index, the Arctic Oscillation, the North Atlantic Oscillation, and the East Pacific/North Pacific index. This study represents the first quantification of yearly breakup and freeze-up dates along entire river systems across the pan-Arctic and allows for a more comprehensive understanding of regional trends, patterns, and drivers of river ice timing in response to both long-term and interannual changes in climate.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C54B..03D
- Keywords:
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- 0738 Ice;
- CRYOSPHERE;
- 0744 Rivers;
- CRYOSPHERE;
- 0746 Lakes;
- CRYOSPHERE;
- 0750 Sea ice;
- CRYOSPHERE;
- 0758 Remote sensing;
- CRYOSPHERE;
- 0758 Remote sensing;
- CRYOSPHERE;
- 0794 Instruments and techniques;
- CRYOSPHERE;
- 4540 Ice mechanics and air/sea/ice exchange processes;
- OCEANOGRAPHY: PHYSICAL