SPEC has developed a Fast Cloud Droplet Probe (FCDP) with state-of-the-art electro-optics and electronics that utilizes forward scattering to determine cloud droplet distributions and concentrations in the range of 1.5 to 50 microns. Though designed for cloud droplet measurements, the probe has also shown reliable measurements in ice clouds. The new electronics include a temperature controlled fiber-coupled laser, FSSP-300 optics with pinhole limiting depth of field (Lance et al. 2010), a field programmable gate array (FPGA), 40 MHz analog-to-digital-converter (ADC) sampling, custom amplifiers, a very small and low power Linux based 400 MHz processor and a 16-Gigabyte flash drive that stores data at the probe.
Particles in the Upper Troposphere/Lower Stratosphere
The PUTLS comprises three individual instruments for the measurement of aerosol number size distribution in the upper troposphere and lower stratosphere: a Nucleation Mode Aerosol Size Spectrometer (NMASS), an Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), and a Portable Optical Particle Spectrometer (POPS). These instruments, along with a Passive, Near-Isokinetic Inlet for sampling atmospheric particles from a fast-moving aircraft, provide a measurement of the UT/LS particle size distribution from 4 to 3000 nm diameter. Aerosol microphysical measurements in the UT/LS are integral to understanding the chemical and radiative processes that control the Earth’s climate, and PUTLS provides data for investigation of topics ranging from new particle formation to long range transport of dust and fine volcanic ash.
