As of yesterday a crew of scientists flew to Chile, where they will be based for a month and will make 17 missions (the 1st mission is scheduled for Oct. 15th) over some of the fastest-changing areas in western Antarctica and its ice-covered coastal waters. This research will be accomplished over approximately a 30-day period and will hopefully bridge the data gap between NASA’s Ice, Cloud, and Land Elevation Satellite, known as ICESat, which has been in orbit since 2003, and NASA’s ICESat-II, scheduled to launch no earlier than 2014. ICESat is nearing the end of its operational lifetime, making the Ice Bridge flights critical for ensuring a continuous record of observations. The reason for the mission is to better understand how much sea-ice is melting, relating to the never dying Global Warming issue, but in the case where hard and true science is concerned and NOT political agenda, it is hard to dismiss some of the facts.
Since the 17 flights lack the continent-wide coverage a satellite provides, mission planners have selected key targets to study. These areas in which sea ice measurements will be collected from are the Amundsen Sea, where local warming suggests the ice may be thinning, the Antarctic Peninsula and West Antarctica, including Pine Island Glacier, where it is believed that sea ice could undergo rapid changes. So how will the scientists measure any change in sea-ice? The answer lies in the instruments that are on the plane flying over the above targeted areas. On the DC-8 will be a:
1.) Airborne Topographic Mapper: A laser altimeter which produces elevation maps of the ice surface.
2.) Multichannel Coherent Radar Depth Sounder: Measures ice sheet thickness and the varied terrain below the ice.
3.) Laser Vegetation Imaging Sensor: Maps large areas of sea ice and glacier zones.
4.) Gravimeter: Measures the shape of the ocean cavity beneath floating ice shelves
5.) Snow radar : Measures the thickness of snow on top of sea ice and glaciers.
Out of the above instruments, the Airborne Topographic mapper was previously used in flights over the Antarctic in 2002, 2004, and 2008 and by retracing some of those flights, as well as the tracks covered by ICESat Satellite, researchers can compare the data sets and determine changes in ice elevation. It is necessary to have these past flights to work from, because satellite data is just not enough information to base upon where the sea-ice is melting and more importantly how much of it is melting. According to scientist Robin Bell at Columbia University's Lamont-Doherty earth Observation who is involved with this project said, "The problem with satellites is, that we can't see through the ice sheet with just satellite data and therefore the technology carried on the plane will help to provide researchers additional information as to the questions regarding why the ice sheet is changing."
Going back in time of the Cold War, it wasn't satellites and airborne test flights gathering sea-ice data, but instead submarines. The upward-looking sonar profiles which gave an estimate of ice thickness, back in the day, becomes useful information today. By having that information from the U.S. Navy submarines and comparing it with the information we currently have, due to advances in technology, we should ascertain a better understanding as to what is occurring at both ends of our globe. Some may ask, "Why all this research, what will sea-ice thickness prove?" The answer is simply, Sea ice influences the Arctic's local weather, ecosystems and global climate. As sea ice melts, there is less white surface area to reflect sunlight into space. Sunlight is instead absorbed by the ocean and land, raising the overall temperature and fueling further melting. Ice loss puts a damper on the Arctic air conditioner, disrupting global atmospheric and ocean circulation. Since Arctic sea ice records have become increasingly comprehensive from the latter half of the 20th century, with records of sea ice anomalies viewed from satellites, ships, and ice charts collected by various countries, now a more detailed look at Antarctica is what is going to occur over the next month. Already past observations of the Arctic Ocean, from scientists Ron Kwok of NASA's Jet Propulsion Laboratory and Drew Rothrock from the University of Washington, Seattle have shown nearly a 50% decrease in ice thickness (winter of 1980 averaged 3.64 meters of sea-ice... winter of 2007, the average was 1.89 meters), so what will scientists find out about the Antarctic and the ice surrounding it over the next 17 trips?
Only time and continued research will be our answer.
Top photo credit: alaska.usgs.gov
Bottom photo credit: NASA
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