September 16-17- ice measurements
September 16
We finished our last ice station with a ‘hop on’ (small station). Now we are heading southwest out of the ice. It is sad to be leaving the ice, but the open water has its own uniqueness- the feeling of being on a ship with the lulling motion and the birds are back! We will now continue our CTD casts.
Today, I would like to talk about ice coring. As mentioned earlier, I was invited on the ice to help with taking an ice core for a salinity study. Ice coring is one of the many activities taking place on the ice. Ice cores are not only taken to study salinity, but also for chemical signatures (patterns), chlorophyll and ice algae profiles, microbe compositions, and different isotope systems, among other things.
Taking an ice core is a very simple procedure. A cordless power drill is attached to the corer with a connector. The drill rotates the corer as it goes down into the ice. When the corer goes down about a meter, the corer is pulled out of the ice. If an ice core longer than a meter is needed, an extension is put on the corer. The deeper the core sample the more challenging it may be to get the core out. It depends on how solid the ice is. After we took the core out of the ice, PhD student Mia Hansen and I took turns sawing and measuring the pieces of ice before putting them into containers. The measurements are important to help figure out the salinity. Once the pieces of ice core are back on the ship, the ice is melted, and that is a funny story in itself. Master student Nicole Stollberg and PhD student Mia Hansen had to find a way to melt the ice. First, they found an aluminum tub. Then they put the white containers holding the ice in the tub. The problem was where to get hot water. They ended up going up and down one deck to a couple of their colleagues’ cabins to get hot water from their showers. This was a very messy process. Once the tub was filled with hot water, the containers floated. They used heavy steel shackles to hold down the containers. When the ice was melted, a sensor was used to measure the conductivity to figure out the amount of salinity. The photo captions contain more details.
I will wrap up the ice discussion tomorrow with talking about the different stations that were deployed on the ice.
Breakfast: eggs and bacon
Lunch: Solyanka (salami, pickle, olive) soup, and goulash
Tea Time: raspberry turnovers
Dinner: fried chicken and mashed potatoes
September 17
We have gone as far east as we are going to go, and are headed northwest back to the Laptev Sea. We are now north of the New Siberian Islands. Even though we are out of the higher concentration of ice, there are still ice floes and pack ice. Enough ice for a few lucky people to spot another polar bear. There is still hope to see one before the cruise is over.
Today, I would like to talk about the different systems that were set-up on the ice. I spent a lot of time talking to Sea Ice Physic Team member Jakob Belter before and after the ice stations. There is some pretty amazing research going on! I hope my description can do it justice. Otherwise, if you are interested in more detail, you may go to the website I mentioned a few days ago.
The Trans-Arctic Ice (TICE) team not only accomplished their goal of two big and six small ice stations, the stations were set up in an almost ideal formation- the big station on an ice floe surrounded by three smaller stations, each on their own ice floe. This isn’t very easy to do when you are depending on the forces of nature.
I would like to begin with the four types of systems that were set-up on the two big stations. Photos of the systems are posted below.
Snow buoy: The snow buoy isn’t really a buoy as the name implies. The snow buoy measures the snow depth and the accumulation of snow on top of the ice. The four cylinders in the corners on the top of the buoy are snow ‘pingers’. They measure the distance from the ‘pinger’ to the surface of the snow to determine the depth of snow. The white cone-shaped object on top, in the middle, is the iridium sensor that transfers the data live. Barometric pressure, and ice and sea surface temperature are also measured.
PAWS: PAWS stands for Polar Area Weather Station. PAWS has a ‘wind vane’ that measures wind speed and direction. The system also measures relative humidity, surface and barometric pressure, and ice and sea surface temperature.
Radiation Station: The Radiation Station has three sensors, two of which are set up in the middle of a tripod. The sensor pointing upward measures incoming solar radiation. The one pointing downward measures the light reflected from the ground. The cable connects the tripod to an anchor. To keep the surface as natural as possible, ablation shields are used- the white square objects underneath the legs of the tripod. Holes were drilled to secure the tripod legs. When you drill a hole and look inside, the hole gets darker, it is whiter closer to the surface because more light is reflected. After drilling the holes, the ablation shields are used to keep the surface as natural as possible. On top of the battery- the yellow case, is a camera. You can see the images on the above-mentioned website.
Bio-Optical IMB: IMB stands for Ice Mass Balance Buoy. Again, this isn’t really a buoy as the name implies. This system measures salinity, oxygen, ice growth, radiation (light transmittance), turbidity, CDOM, and chlorophyll A fluorescence. This system is unbelievable and being successfully set-up for the first time. To get the full effect, refer to the BOBIMB photo below. A hole is drilled through the ice, and when the instrument goes through the ice and hits the water two ‘arms’ fold out that have measurement sensors on the end. On the ice, there is a tripod connected to one of the batteries. The tripod holds a thermistor chain that goes into the ice that has temperature sensors every two centimeters. This system has three batteries, the tan cases. There is a camera on top of one of the batteries.
Each station has an iridium sensor so the data can be checked out in real time. On the six small stations, only a Snow Buoy and basic Ice Mass Balance Buoy (IMB) equipped with a thermistor chain were set-up. The IMB measures air, ice, and water.
Breakfast: porridge, meat and cheese
Lunch: beef cabbage soup, and pork cutlet, and rice
Tea Time: herring, potato, beet, carrot salad
Dinner: baked chicken, vegetables and rice
Good night!