While the 2nd cohort is off to the start of their trip in Greenland, I’m winding down my field experiment this year aboard the U.S. Coast Guard Icebreaker Healy. Just a few days after graduating from the IGERT program I left for Dutch Harbor, AK and have spent the last month aboard the Healy as part of the NASA ICESCAPE mission. This highly interdisciplinary effort incorporates about 50 researchers onboard (and many others back home) seeking to learn more about how the retreating sea ice cover is driving changes in the biological systems of the Chukchi and Beaufort seas. The results should help shed light on what the Chukchi and Beaufort will look like biologically as sea ice continues to retreat.
An important focus of the mission is trying to learn more about whether the current ecosystem is limited by the presence of ice, which greatly restricts the amount of sunlight available for primary productivity, or limited by the availability of nutrients in the upper layers of the ocean. If the phytoplankton are limited by light, removing the sea ice could lead to a huge increase in ecosystem productivity, perhaps making the Chukchi sea look much more like the Bering sea. On the other hand, if the ecosystem is limited by nutrient availability, removing the ice may have a minimal impact on primary productivity. Researchers on board are therefore working to quantify the amount of light penetrating through the sea ice and into the waters below, as well as the movement and availability of nutrients, and correlate both of these to the quantity and types of phytoplankton present. Contrary to common belief that large phytoplankton blooms cannot occur beneath the ice because of lack of sunlight, we’ve been finding that substantial amounts of sunlight are penetrating through the ice, especially in melt pond covered ice. Also, in at least some areas, we actually saw large phytoplankton blooms were beneath the ice where they would be difficult to spot with satellite remote sensing products.
Which brings us to another highly important aspect of this mission; understanding the level of primary productivity from satellite ocean color data in this area has proven challenging because the ice cover may hide significant algae blooms from satellites and because large discharges of sediment and colored dissolved organic matter (CDOM) from Arctic rivers can be hard to distinguish from ocean algae blooms. By actually putting “boots on the ice” NASA is making a commitment to improve the validation of the remote sensing data, and augment it where things like sea ice hide the ocean color from satellites. From onboard the Healy, where we are getting a constant stream of incoming remote sensing data to help guide our work, massive quantities of data from all our sampling and instrumentation, and can just go look out the window to tie it all together, the value of integrating multiple research methodologies to understand a system becomes exceedingly clear.
I don’t want to hijack the IGERT blog from the second cohort, but I just wanted to say how awesome it is to see that what we do in our program in Greenland is a preparation for real-world research. The NASA ICESCAPE mission is all about using an interdisciplinary team approach to understand polar environmental change, just like what the IGERT’s are doing to understand the ecosystem and physical process interactions around Kangerlussuaq. A few photos area attached below, if they intrigue you about what research is going on in another part of the Arctic check out our NASA ICESCAPE blog, see what we’ve been up to, and track us through the last bit of our experiment on this side of the world!
IGERT at Large