A survey of particle measurements in the Arctic from the Forward Scattering Spectrometer Probe model 300

A new instrument, the Forward Scattering Spectrometer Probe (FSSP) 300, was used on the NASA ER-2 during the Airborne Arctic Stratospheric Expedition (AASE) to count and size particles in the size range 0.4-24 microns in diameter. A brief description of the instrument is presented, and observations for each ER-2 flight are summarized. Measurements were made in both type I and type II polar stratospheric clouds as well as in the background sulfuric-acid particles. Total particle concentrations up to 16/cu cm with total particle volumes up to 10 cubic micron/cu cm were observed in some of the polar-stratospheric-cloud events.