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Arctic Ice Extent Understated Because of "Sensor Drift"

dtjohnson writes "The National Snow and Ice Data Center (NSIDC) has been at the forefront of predicting doom in the arctic as ice melts due to global warming. In May, 2008 they went so far as to predict that the North Pole would be ice-free during the 2008 'melt season,' leading to a lively Slashdot discussion. Today, however, they say that they have been the victims of 'sensor drift' that led to an underestimation of Arctic ice extent by as much as 500,000 square kilometers. The problem was discovered after they received emails from puzzled readers, asking why obviously sea-ice-covered regions were showing up as ice-free, open ocean. It turns out that the NSIDC relies on an older, less-reliable method of tracking sea ice extent called SSM/I that does not agree with a newer method called AMSR-E. So why doesn't NSIDC use the newer AMSR-E data? 'We do not use AMSR-E data in our analysis because it is not consistent with our historical data.' Turns out that the AMSR-E data only goes back to 2002, which is probably not long enough for the NSIDC to make sweeping conclusions about melting. The AMSR-E data is updated daily and is available to the public. Thus far, sea ice extent in 2009 is tracking ahead of 2005, 2006, 2007, and 2008, so the predictions of an ice-free north pole might be premature."

2 of 823 comments (clear)

  1. Re:Oh gosh. by Gonarat · · Score: 1, Offtopic

    It's not so much that we are addicted to cars, its just (at least in the U.S.) we have built an infrastructure that depends on cars, trucks, and cheap(er) gasoline and diesel. In Europe, one can travel most anywhere without needing a car. I have a former coworker who likes to travel to Germany, and he goes most anywhere he wants to go by bus or train -- no car needed.

    Unless you live in a major city here in the U.S., you almost always need a car to get around. Louisville, KY, where I live now, has a decent bus system, but if you live outside Jefferson County, you need to drive in to town. When I lived in near Cleveland, Ohio, back in the '90s, we could drive up to Warrensville, park for free, and take the Rapid (light rail) all the way downtown, then walk over to Jacob's Field from Tower City to see the Tribe play.

    The only way to reduce our dependence on petrol driven cars is to either redesign the transportation system to make public transportation more accessible to those outside the cities, or design vehicles that use alternate energy sources. We have spent the last century developing our current system here in the U.S., so it will take time (or a massive project) to replace it.

    --
    Beware of Sleestak
  2. Re:How can people expect... by oh_my_080980980 · · Score: 1, Offtopic

    "Modding me down because you don't like my opinion doesn't make your opinion anymore right just as it doesn't make mine any more wrong, okay?"

    People can mod you down for reasons other opinion. They can mod you down because of facts. Something you don't have a grasp of.

    Jackass.