U.S. Methane 'Hot Spot' Bigger than Expected   
       
   Oct. 9, 2014: One small "hot spot" in the U.S. Southwest is responsible for   
   producing the largest concentration of the greenhouse gas methane seen over   
   the United States - more than triple the standard ground-based estimate --   
   according to a new study of satellite data by scientists at NASA and the   
   University of Michigan.   
       
   Methane is very efficient at trapping heat in the atmosphere and, like carbon   
   dioxide, it contributes to global warming. The hot spot, near the Four Corners   
   intersection of Arizona, Colorado, New Mexico and Utah, covers only about   
   2,500 square miles (6,500 square kilometers), or half the size of Connecticut.   
       
   http://www.nasa.gov/sites/default/files/thumbnails/image/14-280.jpg   
       
   The Four Corners area (red) is the major U.S. hot spot for methane emissions   
   in this map showing how much emissions varied from average background   
   concentrations from 2003-2009 (dark colors are lower than average; lighter   
   colors are higher). Image Credit: NASA/JPL-Caltech/University of Michigan   
   In each of the seven years studied from 2003-2009, the area released about   
   0.59 million metric tons of methane into the atmosphere. This is almost 3.5   
   times the estimate for the same area in the European Union's widely used   
   Emissions Database for Global Atmospheric Research.   
       
   In the study published online today in the journal Geophysical Research   
   Letters, researchers used observations made by the European Space Agency's   
   Scanning Imaging Absorption Spectrometer for Atmospheric Chartography   
   (SCIAMACHY) instrument. SCIAMACHY measured greenhouse gases from 2002 to 2012.   
   The atmospheric hot spot persisted throughout the study period. A ground   
   station in the Total Carbon Column Observing Network, operated by the   
   Department of Energy's Los Alamos National Laboratory, provided independent   
   validation of the measurement.   
       
   To calculate the emissions rate that would be required to produce the observed   
   concentration of methane in the air, the authors performed high-resolution   
   regional simulations using a chemical transport model, which simulates how   
   weather moves and changes airborne chemical compounds.   
       
   Research scientist Christian Frankenberg of NASA's Jet Propulsion Laboratory   
   (JPL) in Pasadena, California, first noticed the Four Corners signal years ago   
   in SCIAMACHY data.   
       
   "We didn't focus on it because we weren't sure if it was a true signal or an   
   instrument error," Frankenberg said.   
       
   The study's lead author, Eric Kort of the University of Michigan, Ann Arbor,   
   noted the study period predates the widespread use of hydraulic fracturing,   
   known as fracking, near the hot spot. This indicates the methane emissions   
   should not be attributed to fracking but instead to leaks in natural gas   
   production and processing equipment in New Mexico's San Juan Basin, which is   
   the most active coalbed methane production area in the country.   
       
   Natural gas is 95-98 percent methane. Methane is colorless and odorless,   
   making leaks hard to detect without scientific instruments.   
       
   "The results are indicative that emissions from established fossil fuel   
   harvesting techniques are greater than inventoried," Kort said. "There's been   
   so much attention on high-volume hydraulic fracturing, but we need to consider   
   the industry as a whole."   
       
   Coalbed methane is gas that lines pores and cracks within coal. In underground   
   coal mines, it is a deadly hazard that causes fatal explosions almost every   
   year as it seeps out of the rock. After the U.S. energy crisis of the 1970s,   
   techniques were invented to extract the methane from the coal and use it for   
   fuel. By 2012, coalbed methane supplied about 8 percent of all natural gas in   
   the United States.   
       
   Frankenberg noted that the study demonstrates the unique role space-based   
   measurements can play in monitoring greenhouse gases.   
       
   "Satellite data cannot be as accurate as ground-based estimates, but from   
   space, there are no hiding places," Frankenberg said.   
       
   Credits:   
   Production editor: Dr. Tony Phillips | Credit: Science@NASA   
       
   More information:   
       
   In March 2014 the Obama Administration announced a strategy to reduce methane   
   emissions under its Climate Action Plan. The strategy includes improving the   
   measurement and monitoring of methane emissions and assessing current methane   
   emissions data.   
       
   NASA monitors Earth's vital signs from land, air and space with a fleet of   
   satellites and airborne and ground-based observation campaigns. NASA develops   
   new ways to observe and study Earth's interconnected natural systems with   
   long-term data records and computer analysis tools to better see how our   
   planet is changing. The agency shares this unique knowledge with the global   
   community and works with institutions in the United States and around the   
   world that contribute to understanding and protecting our home planet.   
       
   For more information about NASA's Earth science activities in 2014, visit:   
   http://www.nasa.gov/earthrightnow   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.99   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)