Passing Efficiency of the Low-Turbulence Inlet (PELTI)

PELTI was a field test program to study the collection efficiency of a new aerosol sampling program.  However, we participated on a piggyback status and used the mission to tests our new Atmospheric Pressure Ionization Mass Spectrometers (APIMS) for determining dimethyl sulfide (DMS) and sulfur dioxide (SO₂­).  We showed that these instruments can determine these two species at 35 hz even when the concentrations are only a few parts per trillion by volume.  We showed that these data can be used to determine the vertical flux of these species (molecules s^-1 m^-2) using a very elegant technique call eddy correlation.  This capability will dramatically improve our ability to study the chemistry of these two species in the marine atmosphere.

DMS and SO₂ are of interest because they are important precursors of H₂SO₄ which plays an important role in cloud formation, which in turn is important in determining how much radiation reaches the earth’s surface.