Tuesday 1 to Wednesday 2 July 2014
For the previous 2 days of the MAGIC campaign we have carried out work around Svalbard to look for methane hydrate emissions off the west coast of the archipelago and to test a new inertial navigation system at high latitudes.
On Tuesday we left Kiruna in Northern Sweden at 0900 UTC (which is another way of saying GMT), transiting at high level before descending to 100 ft above sea level to rendezvous with the Norwegian research ship, the RV Helmer Hanssen, currently carrying out a survey of the methane above seabed bubble plumes, and looking for elevated methane in the atmosphere. We flew past the ship twice before heading to Longyearbyen to refuel and prepare for the next sortie of the day.
The second sortie was a 1400 UTC take off heading out to 10°E then to 84°N at 27000 ft. Stratospheric air was encountered at these high latitudes. Following a leg at 84°N across to 20°E and a successful navigation equipment test we headed back to the 10°E line heading for lower altitudes to look for methane emissions above leads (wide cracks) in the Arctic sea ice pack. Our descents to 100 ft were very intermittent due to low cloud cover, but lead development was seen near 81.5°N, and these became more frequent as we flew south. The edge of the ice pack was close to 80.1°N and fragments of ice from the pack were observed to 79.9°N. Methane seemed to increase very slightly after reaching open water but changes were not much above instrument measurement precision.
After debrief we headed to the centre of Longyearbyen. The taxi drivers have plenty of great stories about the town, some not appropriate for print. We stayed in the Radisson hotel, which apparently was transported from Lillehammer after the 1994 winter Olympics. The cloud cover made the town quite gloomy, not helped by the remnants and scars of coal mining on the hillsides, although residential developments do add some colour.
The first sortie for Wednesday was a 0900 UTC departure aimed at surveying the hydrate bubble line west of Prins Karls Forland where the water depth is approximately 400 m. This has been the focus of extensive acoustic and geophysical study by European groups over the past decade. Many methane bubble plumes have been observed rising from the sea bed, but these tend to dissolve or be oxidized as they rise in the water column and their breaching of the surface is still hotly debated, hence our current atmospheric surveys. The data from the profiles across this zone will now be analysed to see if there is elevated methane, although first impressions are that this is not a very big source in the context of global methane emissions. Frequent sightings of whales and seals were reported back from the flight deck, but from my seat under the wing these went mostly unobserved. A low level (1000 ft) return to Lonyearbyen allowed some great views of the coastal scenery including mountains, glaciers and wetlands.
Another hour was spent over the bubble zone after lunch and refuel before climbing to 25,000 ft for the return transit to Kiruna. Spectacular views of the Norwegian coast were a distraction from watching the methane displays until the start of the descent into Kiruna. A plume of long-range transport of emitted methane was observed and sampled between 20,000 and 18,000 ft, and the air mass history will be analysed to interpret the source of this. We landed in Kiruna at 1700 UTC. We had flown around 13 hours in the 2 days and I had collected close to 50 samples of air for subsequent analysis back at Royal Holloway, University of London. So lots of tired crew and scientists but a very rewarding and informative trip. Hope to see a little more of the midnight sun if I get another opportunity to go up there.
Dr Dave Lowry (Royal Holloway, University of London)