Post from a Scientist: “The First On-Ice Station”

My first steps on the sea ice was four years ago in Barrow, Alaska. Back then I was helping to measure the ice thickness of shorefast sea ice (ice very close and attached to the shore). This was one of the moments in my life that led to the decision to study Arctic climate. I wanted to understand more. Why does the sea ice in the Arctic melt? Why do we have years with very low sea-ice extent, and other years with a large sea-ice extent? For sure there is no easy answer! It’s like doing a puzzle – however, to solve the puzzle, many scientists have to work together. For my PhD, I try to understand some of the puzzle pieces that explain the atmospheric processes that control the sea-ice extent, and yesterday I had the opportunity to see some scientists in action try to solve some oceanic parts of the puzzle. Five scientists deployed an oceanic buoy (also called ice-tethered profiler) on the ice, which is designed to measure properties of the ocean (down to around 800m depth). For example, in this region we can even measure a warmer ocean current that originates from the Atlantic Ocean (far far away from here). To understand the impact this current has on Arctic climate (including ocean, sea ice and atmosphere), we need as many measurements as possible to help solve a couple more puzzle pieces. 

To deploy the buoy, scientists were let down onto the ice in a sort of fishing net that was attached to a crane. Even for some of the well-experienced scientists this was the first time they had to use this kind of amusing “elevator.” The work on the ice started with the deployment of the meteorological buoy (in the photo, the white thing on the sled). While this deployment went quite fast, the deployment of the oceanic buoy (the yellow object in the photo) required almost 4 hours of work. Fortunately the weather was quite good, with almost no wind and temperatures around 0°C (32°F), which is a blessing if you have to work with your bare hands (it’s hard to work with small screws with thick gloves on). It also made the watching for us much more enjoyable. 🙂 Unfortunately we summer school students were not allowed to go on the ice yet. But many of us, including me, cannot wait to finally have the opportunity to get off the ship and out on the ice, to have the full Arctic experience! 

How Does the Buoy Work? You Can Track it Yourself!

The buoy is basically structured in two parts. One part is under the ice (this is a long cable that goes about 800 deep into the ocean with several instruments attached to it), and another part is above the ice (that is the yellow device that looks similar to a bottle cork, and can float if needed). To install the lower part, scientists drill a hole into the ice wide enough to fit the instruments. One of the main instruments is a profiler, which goes up and down along the cable and measures the salinity and temperature of the upper ocean layers (this gives us information about where the water is coming from). Another instrument attached to the cable measures oxygen and other parameters that give more information on the water masses. The yellow cork is connected to the cable with the instruments, and is put on top of the ice to hold the whole structure in place. Even if the ice starts to melt and the hole that scientists made in the ice gets bigger due to melting, the cork will not sink (so it really is kind of a cork). And if all the surrounding ice melts (like in the summer), the cork would float on the water, so the instruments hopefully do not get lost. The yellow cork also includes a satellite sensor that sends out the data directly and connects the buoy to the internet. So you can actually watch the buoy (luckily from your warm home or school)! The data are transferred to the internet in real time, and should be already online now! Check it out here: http://www.whoi.edu/itp – the number of this buoy is 72, and it was deployed at latitude 80°48N and longitude 132°37E.

 – Marie Kapsch