Cavity Ring-Down Technology Applied to the Measurement of
Aerosol Optical Properties
Cadenza employs innovative cavity ring-down technology
to make in-situ measurement of aerosol extinction and
scattering coefficients. The instrument was developed
for NASA-Ames Research Center by Picarro, Inc. under
SBIR. Cadenza recently flew as part of the Asian Dust
Above Monterey (ADAM) and the DOE Aerosol Intensive
Operat-Ing Period flight experiments aboard the Naval
Research Laboratory Twin-Otter aircraft.
Cadenza measures extinction at two wavelengths:
675 nm and 1550 nm. An example of Cadenza extinction
coefficient measurement is plotted at right. On
May 25, 2003 Cadenza sampled this aerosol layer at
about 620 mbar (about 12,500 ft altitude) over Oklahoma.
It is expected that measurements such as these will help
reduce the current uncertainty in estimates of the effect
that aerosols have on climate, help pinpoint sources
and effects of pollution, and provide valuable data needed
for satellite validation.
Simultaneous measurement of aerosol extinction and scattering coefficient
at 675 nm and extinction at 1550 nm
Derived quantities of Absorption Coefficient and single scattering albedo at
Employs Continuous Wave Cavity Ring-Down (CW-CRD) technique
Accuracy: 1% at 1.0x10-6 m-1 (1.0 Mm-1) for 10 sec sample time
Small size: The instrument dimensions are: 19Wx24Lx8H
Associated electronics rack: 35 High
Weight: 90 kg
Developed by Picarro, Inc. and NASA Ames Research Center
Applications: studies of visibility, climate forcing by aerosol, and the
validation of aerosol retrieval schemes from satellite data.
Reno Aerosol Optics Study, 2002, Lab intercomparison
DOE: Aerosol IOP, 2003; flight experiment on Twin Otter
Aerosol Dust Above Monterey (ADAM), 2003; flight experiment on Twin Otter
Extended MODIS wavelength Validation Experiment, 2004.
Caldecott Tunnel Experiment
Atmospheric Brown Cloud Post-Monsson Experiment, Maldives, 2004.