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.
Aerosol Number Concentration
Langley Aerosol Research Group Experiment (LARGE). The "classic" suite of instrumenation measures in-situ aerosol micrphysical and optical properties. The package can be tailored for specific science objectives and to operate on a variety of aircraft. Depending on the aircraft, measurments are made from either a shrouded single-diffuser "Clarke" inlet, from a BMI (Brechtel Manufacturing Inc.) isokinetic inlet, or from a HIML inlet. Primary measurements include:
1.) total and non-volatile particle concentrations (3nm and 10nm nominal size cuts),
2.) dry size distributions from 3nm to 5µm diameter using a combination of mobilty-optical-aerodynamic sizing techniques,
3.) dry and humidified scattering coefficients (at 450, 550, and 700nm wavelength), and
4.) dry absorption coefficients (470, 532, and 670nm wavelength).
LARGE derived products include particle size statistics (integrated number, surface area, and volume concentrations for ultrafine, accumulation, and coarse modes), dry and ambient aerosol extinction coefficients, single scattering albedo, angstrom exponent coefficients, and scattering hygroscopicity parameter f(RH).