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7885Re: [GPSL] 5 Years from Now

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  • Mike Manes
    Aug 1, 2010
      Hi Mark,

      The NOAA profiler, aka "Aircore", has two parts:

      1. The airborne portion is 100 m length of about 1/4" OD tubing, coiled up and
      sealed at one end with a valve at the other. The tube is filled with a
      standard 380 ppm concentration of CO2 and air. Just before launch, the valve
      is opened, so that the tube vents during ascent. Now, during descent, the
      tube refills with ambient air, forming the gaseous equivalent of a core
      sample. On landing the valve is closed, thus sealing off the core sample.
      Due to the internal dimensions of the tube, the CO2 concentration of the
      core sample retains its structure, since diffusion is relatively slow in that
      long, skinny enclosure.

      2. After the flight, the tube is connected to a very sensitive IR
      spectrometer, and the core sample is then pushed out from the end opposite
      from the flight valve using 380 ppm air. The spectrometer is tuned to
      absorption line(s) of the gas species of interest. The 380 ppm "push" gas
      serves as an "eof" marker.

      If the aircore sample get to the lab within 24 hours, the CO2 concentration
      can be resolved with a resolution of 10 m in altitude with a precision of
      better than 1 ppm. As one can understand, high confidence in a timely
      recovery after landing is a key requirement.

      Now, I've heard that there are some folks working on real-time in situ CO2
      analyzers, and EOSS might be flying some of those by 'n by.

      73 de Mike W5VSI

      On 7/31/2010 21:16, Mark Conner wrote:
      > Mike,
      > Any details on the CO2 sensors? The company I work for has some interest in
      > balloon-borne CO2 sensor profiles.
      > Still hoping someday to combine hobby and work.........
      > 73 de Mark N9XTN
      > On Sat, Jul 31, 2010 at 21:58, Mike Manes <mrmanes@...
      > <mailto:mrmanes@...>> wrote:
      > EOSS has flown several in situ atmospheric CO2 and CH4 profilers for NOAA, and
      > some of the results have been quite revealing.

      Mike Manes mrmanes@... Tel: 303-979-4899
      "Things should be made as simple as possible, but not more so."
      A. Einstein
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