MACKENZIE DELTA AND BEAUFORT COAST SPRING BREAKUP NEWSLETTER

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1 MACKENZIE DELTA AND BEAUFORT COAST SPRING BREAKUP NEWSLETTER Report June 19, 2018 Friends of Steven Solomon (Dustin Whalen, Paul Fraser, Don Forbes) Geological Survey of Canada, Bedford Institute of Oceanography tel: Welcome to Breakup 2018 Welcome to the 2018 Mackenzie and Beaufort breakup season We are now into our 13th season of the breakup newsletter, which was started by Steve Solomon in This year is the third breakup season for the Mackenzie-Beaufort Breakup group on Facebook Over time we hope this forum hosted in the ISR will take over as the main place to share observations and experience during breakup in the Delta and the coastal communities of the region. Funding for our current breakup monitoring activity is from the Climate Change Geoscience Program of the Geological Survey of Canada, Natural Resources Canada. Again this year we are posting the newsletters on the CACCON website: Please let us know if you do not wish to receive these reports (contact info above) and we will take you off the list. For those of you living in the north, we welcome photos, observations of timing of events, or anything out of the ordinary, and we thank you for all of the feedback received so far. Water-level data are courtesy of Environment and Climate Change Canada [ECCC] (Water Survey of Canada) and derived from the real-time hydrometric data website at which we acknowledge with thanks. Weather forecasts are also courtesy ECCC (Meteorological Service of Canada) at Current Conditions It s another cloudy day in the region with chances of morning showers throughout. Inuvik has a forecast high of 9 C and an overnight low of 5 C. In Aklavik, the forecast high is 7 C with NW 20 km/h wind becoming light this afternoon. Temperatures are cooler in Tuktoyaktuk with a high of 4 C and NW 20km/h wind with gusts to 40 km/h. Sachs Harbour and Ulukhaktok also remain cool with temperatures expected to fall from daytime highs of 4 C and 6 C to below freezing overnight (-3 C and -1 C respectively). The air is currently

2 warmer in Paulatuk (high 14 C) but the temperature there is expected to fall to 1 C tonight. Water levels Water levels have now fallen to near summer levels throughout the region, with levels in the outer delta gauges responding to water level variations in Mackenzie Bay. This is evident in Reindeer Channel at Ellice Island (10MC011), where the daily mean level continues to drop slowly while showing two small increases in recent days, similar to the post-flood variability in past years (Figure 1). Figure 1. Daily mean water levels in Reindeer Channel at Ellice Island (10MC011) for the past decade with 2018 shown in black. Satellite Imagery The melt front in Kugmallit Bay had advanced to less than 5 km from the Tuk harbour entrance yesterday and we anticipate that it is already much closer (Figures 2 and 3). It is also rapidly expanding northward in the bay including both sides of Hendrickson Island. The landfast ice edge is still well offshore, 40 km north of Toker Point and >30 km north of Pelly Island, but we can see signs of weakening over large areas. Melt fronts off the various Mackenzie Delta distributaries also continue to advance seaward. In western Mackenzie Bay off Shallow Bay, the ice bridge is now quite narrow and fractured, so it is not likely to last much longer. Along the Yukon coast, there has been a significant loss of landfast ice and the coast from Kay Point to King Point is now almost entirely ice-free (Figure 2). Herschel Basin is still full of ice and Herschel Island remains encased, although the landfast ice along its north coast, as usual, is very narrow. There is a small melt pool in Phillips Bay off the Babbage Delta. 2

3 Figure 2. NASA Worldview Corrected Reflectance from the NOAA/NASA/Suomi NPP satellite with VIIRS for 18 June 2018, showing the Beaufort coast from the Alaska border to Cape Dalhousie. Figure 3. A closer view of the northern delta and Kugmallit Bay: NASA Worldview Corrected Reflectance from Terra MODIS for 18 June

4 In Amundsen Gulf, the southwest corner of Banks Island, including Sachs Harbour, still has substantial landfast ice cover (Figure 4). At Ulukhaktok, the prospects for open water have receded a bit, as large floes have moved in against the coast, protecting the small areas of landfast ice in the three coves. Unfortunately, Darnley Bay and Paulatuk were under cloud yesterday, but a clearer image from Sunday showed significant expansion of open water off the mouths of the Hornaday and Brock rivers (Figure 5). Landfast ice remained in place in the harbour and along the outer shore in front of Paulatuk. Figure 4. NASA Worldview Corrected Reflectance from the NOAA/NASA/Suomi NPP satellite with VIIRS for 15 June 2018, showing Amundsen Gulf and the eastern ISR communities. 4

5 Figure 5. NASA Worldview Corrected Reflectance from Terra MODIS for 17 June 2018, showing Franklin Bay and Darnley Bay. We would really appreciate any eyewitness reports or photos from Tuk, Sachs, Paulatuk, or Ulukhaktok, as there is only so much we can see and interpret from the satellite images. If you think we have misinterpreted or otherwise missed the mark, please let us know. On-theground observations are always encouraged on the Mackenzie-Beaufort Break-up page hosted by the Joint Sec on Facebook. Summer is coming and the sun will be at its highest for the year in another couple of days. Stay safe as you get ready to venture out on the water. 5