To prepare for a research flight takes quite some time and involves many people. It starts in general 3-4 days in advance when some scientist sit together over the forecasts and think about the most interesting atmospheric situations to probe. Two days in advance they hand over a preliminary flight plan to the HALO flight operations team. These colleagues from the German Aerospace Center (DLR) talk to Air Traffic Control (ATC). A day in advance this preliminary flight plan is updated with the recent forecast.
Today was research flight number 5 of the WISE campaign. This flight went from Shannon to Iceland and its aim was to study an atmospheric gravity wave. The wave was excited by wind over the Icelandic mountains and propagates vertically to the flight altitude of 14km and even higher. A similar wave was already observed during a previous campaign in January 2016 over the same location.
Every great scientific campaign has to come to an end. The POLSTRACC/GW-LCYCLE/GWEX/SALSA campaign as well. Today HALO took off for the last time in Kiruna and is on its way home to Oberpfaffenhofen. And of course HALO also has to say goodbye to Kangerlussuaq, where it refueled so many times during this campaign phase. So right now they are approaching Greenland again for a last stop over. As always you can follow HALO on Gloria Watch.
Don’t be sad now, it is not the very last flight of this campaign. There will be one or two more flights heading from Oberpfaffenhofen to the South (or at least towards subtropic air masses – let’s see where that will be), before the campaign finally finishes next Sunday.
After yesterdays 11 hours flight with refuelling stop in Kangerlussuaq in Greenland, today we are already preparing for take-off again. And we are going to – try a guess – Greenland. There are already jokes going on, that we should have taken the base in Iceland, as many flights brought us to the Canadian coast and over Greenland. Luckily HALO has such a long range – it could fly till San Francisco without refuelling.
Combining different scientific goals into one flight is a very complex process. The flight planning for the 15th scientific flight of the POLSTRACC/GW-LCycle Campaign started three days in advance. Different Teams presented their ideas about where to fly. Fast (that means after just 3 hours of discussion) a conclusion was made that a complex tropopause structure approaching over the Atlantic was a very interesting scientific goal and that could be combined with sampling a gravity wave structure over Northern Scandinavia. Two days before the flight, the plans got more detailed and everyone concluded on probeing the structure the moment it hits the Norwegian coast. A preliminary flight plan was made and handed over to the airtraffic control of the different countries. One day in advance another flightplanning meeting was set at 10:30am to finalise the flightpath according to the latest meteorological forecasts. Just when everything was finalised the info arrived that there will be a big military excersise in Norway exactly when and where we wanted to fly and the airspace will be closed. The planned flight was not possible anymore.
Today I will mainly show you the advantages of being close to the Artic Circle. Every few days you can see an Aurora. For those of you who have never seen one my colleagues made an awesome video, which you can see below. There you can see how they move across the sky. Another advantage of the location of Kiruna in the far North are the low temperatures throughout the whole winter season. That makes the Icehotel possible, which is built every winter since 1989.
Today a flight with both planes HALO and Falcon to southern Scandinavia was planned. On that flight we want to measure gravity waves. Gravity waves are periodic movements of the air, which lead to temperature and wind fluctuations. Gravity waves are excited in the troposphere for example through wind blowing over a mountain ridge. They transport energy from the troposphere into the higher stratosphere. The breaking waves deposit energy and drive global atmospheric circulations. Over southern Scandinava the polar jet is today blowing over the Norwegian Alps, where then mountain waves (one kind of gravity waves) are excited. The wave fronts are oriented parallel to the mountains and therefore in North-South direction. The flight pattern crosses the wave fronts on different altitudes several times to get a full picture of the wave.