Colloquium, Tuesday, Oct. 6, 3:00 pm, EN6085A: (ical.ics)

  The DOE Gulfstream-1 research aircraft participated in the VOCALS study (10/15 to 11/15/2008), based out of Arica, Chile. This was a study of the marine stratus clouds off the Chile/Peru coast and the G-1 was outfitted with both cloud microphysical, meteorological and aerosol sampling instrumentation.  The CAPS (Cloud, Aerosol and Precipitation Spectrometer) was the principal instrument for cloud sampling and had been modified for high speed Particle by Particle (PbP) sampling which allowed individual cloud droplet sampling up to 544 droplets per cc with a spatial resolution of 0.005 mm. This permitted cloud microphysical structure to be resolved in great detail, which included observation of up and down drafts on cloud droplet and CCN concentrations, narrow downdrafts, less than 20 m wide and its effect on cloud droplets, unimodal and bimodal cloud particles distribution, and the effect of turbulence on drizzle and cloud particle concentration.