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NASA's DC-8 takes off for a science flight from Thule, Greenland. The first half of the Arctic IceBridge 2010 mission is now complete, and crew returns to Greenland in May 2010 for the remainder of the campaign. Credit: NASA/Michelle Williams
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On April 19, 2010, the IceBridge team flew underneath the clouds in difficult conditions to collect critical data for monitoring changes in sea ice in the Arctic Ocean. Credit: Michael Studinger
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Michael Studinger: On the Sea Ice Flight that Almost Wasn't
The 2010 Operation IceBridge mission to the Arctic is nearing its halfway point and wrapping up flights with NASA's DC-8 research airplane. In just over four weeks since leaving Palmdale, Calif., on March 21, scientists and crew have flown 14 successful missions over the Arctic Ocean and the Greenland Ice Sheet. They have been in the air for more than 120 hours and have flown a distance greater than 1.5 times around the world.
IceBridge project scientist Michael Studinger, from the Goddard Earth Science and Technology Center at the University of Maryland - Baltimore County, wrote from Thule, Greenland, to discuss some of the mission's accomplishments and critical moments, including one important flight that was almost thwarted by the Arctic weather.
The mission called for a key overnight flight to Fairbanks, Alaska, to map sea ice. Why was this a priority?
The flight from Thule to Fairbanks was designed to cross the entire Arctic Ocean - from Greenland to Canada to Alaska - and map all the different varieties of sea ice. This mission was a very high priority because it could provide a detailed snapshot of sea ice conditions over a very large part of the Arctic. We can compare this long cross-section with measurements collected during the Arctic 2009 campaign. These measurements allow us to detect and quantify changes in sea ice over time with unprecedented detail.
What was involved in planning such a flight?
We first planned to fly and stay overnight in Fairbanks. That meant we would have to move more than 30 people, critical aircraft, science equipment, and spare parts to Alaska, clear customs and immigration, arrange ground support for the aircraft, and make hotel accommodations for the crews. It was difficult to coordinate logistics because we didn't know when the flight would happen. We had made this flight the number one priority every morning since we got here, but were not able to take off due to unfavorable weather conditions along the flight path. By mid-April, we had only three "fly days" left and we hadn't accomplished the sea ice mission. But then the situation in Thule changed.
How did the situation change?
Because of a major Ukrainian-Danish military resupply mission with a large Ilyushin aircraft, the air traffic tower on the airfield in Thule stayed open much longer than usual. That gave us an opportunity to fly out of and return to Thule Air Base without having to land in Fairbanks, and gave us much more flexibility in responding to changing weather conditions.
How did weather influence the flight?
One of the difficulties in launching such a long mission is that we need good weather over a very large part of the Arctic Ocean. This does not happen very often, and the weather has generally been very uncooperative this year. By the time we had to make a go/no-go decision each morning, we didn't have good satellite images available because the route was west of us and often in the dark. There are no weather stations along this route that could give us an indication about the conditions. So in our decision-making, we had to depend on satellite images from the previous day and numerical weather forecasts. But neither the forecast models nor satellite images show the weather features that are most important to us: low clouds and ice fog that disrupt the laser measurements.
So how did you get the flight in?
On the morning of April 19, IceBridge senior scientist John Sonntag, of URS Corporation in Wallops Island, Va., and I were attending our 6:30 a.m. weather briefing. We usually have 15 minutes to make a decision about which mission to fly before the DC-8 gets pushed out of the hangar and fueled before take-off. That morning, the forecast indicated very low visibility and even icing conditions along much of the flight path. John and I spent an hour going through every piece of information from the meteorologists. We're certain that we set a new record for the longest weather briefing in Thule.
We decided to launch the sea ice flight, which was probably the most difficult weather call we've ever made. The conditions were marginal and often poor, but we were able to complete 80 percent of the planned path by flying under the clouds. To fly a big jet in poor visibility … 700 feet over the ice surface … going 240 knots…and for nine hours…that's quite something. John and I were incredibly relieved that we made the right decision. We have fantastic pilots.
NASA's Earth Science News Team