First Global Maps from Orbiting Carbon Observatory   
       
   Dec. 19, 2014: The first global maps of atmospheric carbon dioxide from NASA's   
   new Orbiting Carbon Observatory-2 mission show elevated carbon dioxide   
   concentrations across the Southern Hemisphere from springtime biomass burning   
   and hint at potential surprises to come.   
       
   At a media briefing  at the American Geophysical Union meeting in San   
   Francisco, scientists from NASA's Jet Propulsion Laboratory, Pasadena,   
   California; Colorado State University (CSU), Fort Collins; and the California   
   Institute of Technology, Pasadena, presented the maps of carbon dioxide and a   
   related phenomenon known as solar-induced chlorophyll fluorescence and   
   discussed their potential implications.   
       
   http://tinyurl.com/nom85mu   
       
   Global atmospheric carbon dioxide concentrations from Oct. 1 through Nov. 11,   
   as recorded by NASA's Orbiting Carbon Observatory-2. Carbon dioxide   
   concentrations are highest above northern Australia, southern Africa and   
   eastern Brazil. Image Credit: NASA/JPL-Caltech   
       
   A global map covering Oct. 1 through Nov. 17 shows elevated carbon dioxide   
   concentrations in the atmosphere above northern Australia, southern Africa and   
   eastern Brazil.   
       
   "Preliminary analysis shows these signals are largely driven by the seasonal   
   burning of savannas and forests," said OCO-2 Deputy Project Scientist Annmarie   
   Eldering, of JPL. The team is comparing these measurements with data from   
   other satellites to clarify how much of the observed concentration is likely   
   due to biomass burning.   
       
   The time period covered by the new maps is spring in the Southern Hemisphere,   
   when agricultural fires and land clearing are widespread. The impact of these   
   activities on global carbon dioxide has not been well quantified. As OCO-2   
   acquires more data, Eldering said, its Southern Hemisphere measurements could   
   lead to an improved understanding of the relative importance in these regions   
   of photosynthesis in tropical plants, which removes carbon dioxide from the   
   atmosphere, and biomass burning, which releases carbon dioxide to the   
   atmosphere.   
       
   The early OCO-2 data hint at some potential surprises to come. "The agreement   
   between OCO-2 and models based on existing carbon dioxide data is remarkably   
   good, but there are some interesting differences," said Christopher O'Dell, an   
   assistant professor at CSU and member of OCO-2's science team. "Some of the   
   differences may be due to systematic errors in our measurements, and we are   
   currently in the process of nailing these down. But some of the differences   
   are likely due to gaps in our current knowledge of carbon sources in certain   
   regions -- gaps that OCO-2 will help fill in."   
       
   http://tinyurl.com/ms99nlm   
       
   This map shows solar-induced fluorescence, a plant process that occurs during   
   photosynthesis, from Aug. through Oct. 2014 as measured by NASA's Orbiting   
   Carbon Observatory-2. This period is springtime in the Southern Hemisphere and   
   fall in the Northern Hemisphere. Image Credit: NASA/JPL-Caltech   
   Carbon dioxide in the atmosphere has no distinguishing features to show what   
   its source was. Elevated carbon dioxide over a region could have a natural   
   cause -- for example, a drought that reduces plant growth -- or a human cause.   
   At today's briefing, JPL scientist Christian Frankenberg introduced a map   
   using a new type of data analysis from OCO-2 that can help scientists   
   distinguish the gas's natural sources.   
       
   Through photosynthesis, plants remove carbon dioxide from the air and use   
   sunlight to synthesize the carbon into food. Plants end up re-emitting about   
   one percent of the sunlight at longer wavelengths. Using one of OCO-2's three   
   spectrometer instruments, scientists can measure the re-emitted light, known   
   as solar-induced chlorophyll fluorescence (SIF). This measurement complements   
   OCO-2's carbon dioxide data with information on when and where plants are   
   drawing carbon from the atmosphere.   
       
   "Where OCO-2 really excels is the sheer amount of data being collected within   
   a day, about one million measurements across a narrow swath," Frankenberg   
   said. "For fluorescence, this enables us, for the first time, to look at   
   features on the five- to 10-kilometer scale on a daily basis." SIF can be   
   measured even through moderately thick clouds, so it will be especially useful   
   in understanding regions like the Amazon where cloud cover thwarts most   
   spaceborne observations.   
       
   The changes in atmospheric carbon dioxide that OCO-2 seeks to measure are so   
   small that the mission must take unusual precautions to ensure the instrument   
   is free of errors. For that reason, the spacecraft was designed so that it can   
   make an extra maneuver. In addition to gathering a straight line of data like   
   a lawnmower swath, the instrument can point at a single target on the ground   
   for a total of seven minutes as it passes overhead. That requires the   
   spacecraft to turn sideways and make a half cartwheel to keep the target in   
   its sights.   
       
   The targets OCO-2 uses are stations in the Total Carbon Column Observing   
   Network (TCCON), a collaborative effort of multiple international   
   institutions. TCCON has been collecting carbon dioxide data for about five   
   years, and its measurements are fully calibrated and extremely accurate. At   
   the same time that OCO-2 targets a TCCON site, a ground-based instrument at   
   the site makes the same measurement. The extent to which the two measurements   
   agree indicates how well calibrated the OCO-2 sensors are.   
       
   Additional maps released today showed the results of these targeting maneuvers   
   over two TCCON sites in California and one in Australia. "Early results are   
   very promising," said Paul Wennberg, a professor at Caltech and head of the   
   TCCON network. "Over the next few months, the team will refine the OCO-2 data,   
   and we anticipate that these comparisons will continue to improve."   
       
   Credits and more information:   
   Production editor: Dr. Tony Phillips | Credit: Science@NASA   
       
   To learn more about OCO-2, visit: http://oco2.jpl.nasa.gov/   
       
   Caltech manages JPL for NASA.   
       
   NASA monitors Earth's vital signs from land, air and space with a fleet of   
   satellites and ambitious 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 this year, see:   
   http://www.nasa.gov/earthrightnow   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.99   
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