It’s a sign of the times that while starting to type CODA (Coastal Ocean Dynamics in the Arctic), my computer keeps suggesting COVID-19. Yet, despite everyone’s current focus on the pandemic, there were CODA projects in 2019 and 2020, and while there will not be a CODA cruise in 2021, the data from these expeditions will help shape our future understanding of the interaction between ice, waves, and the Arctic coastline.
The CODA 2019 team spent 20 days aboard the R/V Sikuliaq alongside a team from the GO-WEST project (studying arctic cod and other fauna below autumn sea ice). The CODA project had several objectives, and like many expeditions in the Arctic, some unexpected challenges and opportunities. The long-term objective was to recover and re-deploy moorings to sit at various depths and distances from the shore, so they could measure the ice-wave interactions over a several year span. These moorings would be recovered on the 2020 CODA cruise.
In 2019, one of the unexpected data sets that the crew collected occurred during a four-day wave event near Icy Point in the Chukchi Sea. With a storm approaching, the Sikuliaq positioned itself in a field of pancake ice and proceeded to collect data from 104 stations while facing 30+ knot winds and 3-meter (10-foot) waves.
Pancake ice has been (until recently) relatively rare in the Arctic - it’s much more common in the Antarctic. It forms when ice crystals, called frazil ice, are pushed by rough ocean conditions into slushy disks with raised edges that look like pancakes. In the past, the conditions in the Arctic Ocean didn’t promote this formation, but with less overall ice cover in the region and increasing wave action, this type of ice is becoming more common.
The team repeatedly deployed and recovered SWIFT (Surface Wave Instrument Float with Tracking) buoys in the ice. These are free-floating devices that measure wave action and energy dissipation at the surface and are useful in collecting data about the ice-wave interactions.
In 24-hour shifts for four days in blizzard-like conditions, the scientists collected data about the wave activity, ice conditions, water temperature, water column features, and even sediment levels in the water. They endured rough seas and cold temperatures, and while they did not know what their data would show, they did know that they were in a unique position to collect information that might add to the understanding of the dynamic interactions between the ocean, ice and land.
Fast forward one year, and team members Lucia Hosokova, Jim Thomson and others published their findings in the November 2020 issue of the Journal of Geographic Regions (JGR): Oceans. Their article Attenuation of Ocean Surface Waves in Pancake and Frazil Sea Ice Along the Coast of the Chukchi Sea represented the analysis of this data. They concluded that the presence of the pancake ice reduced the wave heights by 40% over a 5 km distance, and that the effects were most apparent along the ice edge. Because this data was so specific, these results should prove very useful in developing and refining models of ice activity and climate in the Arctic.
The CODA 2020 cruise – combined with the COVID-19 pandemic - presented many different challenges. The scientists were able to recover moorings and collect data from the 2019 deployment and are working to analyze their data.
The CODA scientists spent four days on a ship in the Arctic Ocean in the middle of a blizzard just to collect data for science and answer a question. Where in the world would you go, and what would you be willing to do to answer a question that you have?