![]() ![]() – To be part of an expedition to such a remote area and being able to participate in fieldwork together with polar scientists from other disciplines is really valuable. Participating in the expedition to northern Greenland were PhD students Felicity Holmes and Abhay Prakash at Stockholm University. Unique opportunities with ship expeditions The information is important as warm water reaching the floating glacier tongue can lead to melt below the waterline. – The buoys allow us to investigate to what extent relatively warm Atlantic water penetrates Ryder Fjord and comes close to the front of Ryder Glacier. ![]() The buoys are used for long-term measurements of water temperatures until August 2020, when they will start transmitting data via a satellite connection. To measure the temperature in the water near the glacial front, LoTUS buoys have been used at 225- and 415-meters depth, anchored two meters above the seabed. However, satellite images will be used to extend the study’s time frame, says Nina Kirchner. Thanks to the pictures taken every five seconds, calving style information can be obtained, something that cannot be done with satellite images. The next step is to analyse the images in connection with meteorological data recorded from icebreaker Oden, to try to determine which environmental factors affect the timing and intensity of calving. We took over 140,000 images that reveal calving events of various sizes. – The camera was placed ashore about a kilometre from the north side of the calving front of Ryder Glacier at an altitude of 371 meters above sea level, so that the entire glacier front was visible in the photographs. The purpose is to understand which environmental factors that affect the pace of ice release from the glacier (calving) and to be able to classify different types of calving. Time-lapse photography, i.e., photography that captures a longer time period, and LoTUS buoys (Long Term Underwater Sensing), are two of the methods used during the Ryder Glacier expedition. Uses pictures and temperature measurements With an improved description of frontal ablation in numerical models, prognoses regarding future mass loss from glaciers will become less uncertain, says Nina Kirchner, glaciologist at Stockholm University. Our measurements and observations from Ryder Glacier and Petermann Glacier will be used in conjunction with numerical models of glacier dynamics that we develope in our working group. However, direct observations of calving and submarine melt are challenging to carry out, and previous observations are rare. – The pace of frontal ablation results in uncertainty in future forecasts regarding sea level rise. ![]()
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