Transects in the ice

For a few days now RV Lance has been sailing along the ice edge north east of Svalbard and we have met some of the challenges we expected to meet, when planning the cruise.

polar bear jumping into water

The counting has started – polar bear ahead! Photo: Tiago Marces / Norwegian Polar Institute

Our main job now is to fly with the helicopter inn over the sea ice, in straight lines running in a north-south direction and placed 4,5 km apart, covering all of the sea ice in the area.

We fly at 200 feet altitude (about 80m), at a speed of 100 knots, so in one hour we get 100 nm into the sea ice and have one our back out again. The helicopter has 2 hours and 40 minutes endurance on one tank of fuel, so our flights are planned to take up to two hours and we then have 40 minutes reserve flying time.

Around the clock

We have two teams on the helicopter (including two pilots) and also two whale observer teams, so we can run both polar bear and whale transect around the clock, if conditions allow.

We did however experience in 2004, during the last survey, that weather often put a stop to our plans, and most often it was fog that forced us to stop flying. Humid and relatively warm air transported from the south condensate over the cold ocean and the sea ice and forms fog.


Our helicopter needs good visibility to operate, so we cannot fly unless we have good view of the surroundings, also icing on the aircraft is a risk under such conditions, something that can dramatically reduce the flying capabilities of the aircraft.

To put it short, we have to be careful when flying up here. Despite these challenges we have been able to cover a number of transects and have observed polar bears and secured the necessary data for the recordings. So far the transects have been relatively short, but we hope for a weather change that would bring us cold dry air from the north, giving us clear sky and good visibility for the really long transects into the ice.

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