CASCADES: A Journey Along Greenland’s Coast Where Ocean Meets Ice

CASCADES: A Journey Along Greenland’s Coast Where Ocean Meets Ice By Simon Bélanger, Université du Québec à Rimouski (UQAR), Québec, Canada What an extraordinary feeling it is to witness the beauty of these icy landscapes, where the ice sheet flows down to the sea through fjords with steep, towering walls—watching, in real time, as the ice sculpts this raw, mineral landscape… Breathtaking! Into the Unknown We all know that Greenland’s glaciers are melting fast in response to global warming. But how that meltwater changes the surrounding ocean is still largely unknown, since field observations here are scarce and sailing among sea ice and icebergs is challenging and costly. From August 6 to September 3, 2026, I had the rare opportunity to join the CASCADES (a ‘thematic’ name, not an acronym) expedition, sailing more than 3,000 nautical miles (5,500 kilometers) to reach the Robeson Channel. This body of water runs between Ellesmere Island and Greenland at 82°N, where cold water and sea ice flow south out of the Arctic Ocean. Along the way, we collected oceanographic measurements in fjords and near settlements with names as striking as the landscapes themselves—Ilulissat (Jakobshavn), Uummannaq, Kullorsuaq, Petermann, and Qaanaaq (Thule)—places where ocean, ice, and meltwater interact. Path to the Sea As an ocean-color remote-sensing specialist, my job on board was to measure how sunlight interacts with the water and its constituents—the same frequency of light (wavelength) NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite measures from space—and to collect water samples to identify the tiny drifting algae, or phytoplankton, and non-living suspended matter that give the ocean its colorful aspect. These measurements will help validate what PACE measures from orbit. But CASCADES is much bigger than my own work: it is an international (Canada, Switzerland, France, and Greenland), multidisciplinary expedition bringing together glaciologists measuring ice thickness, marine-mammal observers, microbiologists, geologists, and biogeochemists. Together, we are trying to understand how carbon and nutrients move from the ocean’s surface to the deep sea, and how glacier meltwater changes that journey. Ops and Opportunity No two days aboard the CCGS Amundsen were alike. Our operations ranged from water sampling with a CTD rosette (an instrument that measures temperature, salinity, and depth), to catching zooplankton and fish with nets, to pulling up surface sediments and six-meter-long sediment cores that let us reconstruct the history of these fjords. And, of course, I had my own work: measuring how light travels through the water column at different wavelengths across the visible spectrum and taking water color spectra at the surface. These water color spectra tell us about the abundance of biological activity and possibly about the composition of the phytoplankton communities that form the base of the marine ecosystems. International Exploration The CASCADES expedition is led by Jean-Éric Tremblay of Université Laval, with funding from Amundsen Science, l’Institut Nordique du Québec (INQ), the Swiss Polar Institute (SPI), and the Transforming Climate Action (TCA) initiative. My remote sensing work is supported by the Canadian Space Agency (CSA).