Day 8. Beaufort sea ice and a terrestrial survey home. Today we spent a long day out over the sea ice. The goal was to under-fly Sentinel 3 and Sentinel 1 tracks with the Icebird (EM bird) and the CryoSAR, and to aim to survey a SmartICE site just north of Tuktoyaktuk on the ice (more about SmartICE in a later post). Sentinel 3 has an interferometric radar altimeter which measures sea ice thickness from space with some uncertainty which the EM bird can help to resolve for different ice types. Sentinel 1 is an imaging radar system that is great for characterizing ice types. We are interested in using the CryoSAR observations at Ku and L-band to help resolve snow thickness on sea ice and the underlying ice properties. The image below shows a map of the day's coverage.
Map of the flight track for day 8.
The flight took us directly over the Mackenzie River delta which we saw the day before. It is an amazing place in the winter with an incredible number of branching and interleaving channels. In the far distance the Ivavik National Park mountains could be seen and before we knew it we were out over the polynya and the sea ice. The right turn was under the S3 track and so the Icebird was lowered to within 40 feet of the sea ice.
Mackenzie River delta towards the north.
Mackenzie River delta
Mackenzie River delta looking west.
As we headed out over the ice, survival suits were donned. These are incredible "onesies" to wear. The arms have neoprene cuffs and the feet as completely enclosed in the suit. The main zip is heavy duty and inside the hood of Jeff's and mine, a life vest is folded up ready for deployment should it be needed. IN addition, there are attention-seeking whistles and lights and a survival knife.
A happy sandwich-eating Jeff modelling a Viking survival suit, and Christian modelling an alternative, but equally effective, brand of suit while managing the Icebird.
As the flight continued we settled into our routine and rhythm of the onboard work: Christian managing the Bird, Martin the lidar and cameras, Arttu and Jeff the snow radar and MACS camera, and Richard the CryoSAR radar. Alan and Kyle were chief pilot and co-pilot. Their expertise makes the science flights doable as they can fly a line often to within 10 feet in xyz of what is required.
Discussions on lidar and CryoSAR operations
The sea ice is an amazing surface to fly over. Not only are there the standard types of ice (first year ice, multi-year ice), but we flew over fast ice (connected or tied to the coast), nilas and frazil ice part of the ice forming stages, and on the ice there might be pressure ridging, where two ice floes push against each other and crumple upwards, and leads in the ice where ice floes diverge. Oh, and of course, there is generally snow on sea ice which can load the ice in terms of its free-board (height above the ocean) It is amazing to see! It is also difficult to photograph unless you are on the ground but Jeff's photos below are very nicely framed!
View over the polynya
View over the polynya
On the way back from the Beaufort Sea, we ere able to capture laser scanner measurements of the land along the Inuvik to Tutoyaktuk highway (ITH) for the NWT government. Given the biggest snow accumulation season for many years, they are interested in what the maximum snow depth is and an excellent way of doing this is to use a laser scanner which sends pulses of light to the ground and measures the round-trip travel time. This can be used to estimate distances very accurately (in this case, distance form the aircraft to the ground). when you compare that with a bare earth elevation model, the difference gives you snow depth (height of snow surface [from the laser] - height of bare ground [from an elevation model] = snow thickness). The laser scanner is used with many of the instruments on board the Polar 5 so we were glad to help the NWT. The ITH is a key communication link between Inuvik and Tuktoyaktuk which is a great set-off point for exploring the many pingoes which are a distinctive landscape feature of this part of the world.
Ihe ITH highway
After return it was time to start packing the equipment ready for the onward flight to Cambridge Bay. Packing the aircraft is a real art. Thee aircraft's maximum load is a little over 2000 kg of cargo. This includes a spare aircraft wheel. With the science equipment already weighing a fair load and then there is the science experiment equipment and spares, plus the aircraft spares and then the people, this takes some thinking to get right. Luckily with Alan the pilot, Dwayne the mechanic and Kyle the co-pilot, the expertise in the packing and loading department is first-rate.
Loading the crates
Loading the spare aircraft tyre ...
...onto the aircraft.
On board view next to a passenger seat.
After loading it was dinner time and Alestine's in Inuvik provided some great food. It is a small 15 seat restaurant next to the school bus on the way to the ice road on the Mackenzie river. The fish tacos were great!
Tomorrow: transit to Cambridge Bay.
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