W. PATRICK ARNOTT

Associate Research Professor
Atmospheric Sciences

EDUCATION:

Ph.D., Physics, Washington State University, Pullman
M.S., Physics, Washington State University, Pullman
B.S., Physics, University of Southern Colorado, Pueblo

PROFESSIONAL INTERESTS:

Dr. Arnott's previous research has included work on a general formulation of thermoacoustics, model development and verification for sound propagation in ideal porous materials, in situ acoustic detection of soil properties and use of laser doppler vibrometry for acoustic-to-seismic wave coupling measurements, backscattering of light by freely rising spheroidal bubbles in water with application to ocean optics, computer simulations of farfield radiation patterns of phased-array laser diodes, and x-ray diffraction from liquid surfaces to determine the atomic radial distribution function. His current experimental and theoretical research efforts include Fourier Transform Infrared spectrometer determination of the scattering and absorptive properties of ice crystals in the IR region of 2 µm to 20 µm, novel instrument development of photoacoustic spectrometers for use in directly measuring light absorption by aerosols, and cirrus cloud microphysics measurements and analysis using research aircraft. These efforts are useful for quantifying the role of ice clouds and aerosols in the earth's radiation budget and for producing useful semi-empirical radiation and scattering relations for aerosols and ice clouds. He is also continuing to study fundamental properties of thermoacoustic refrigerators and sound sources, with application to finding an efficient alternative to CFC-based refrigeration.

RESEARCH AREAS:

Aerosols, Cirrus Clouds

SELECTED PUBLICATIONS:

Arnott, W. P. and P.L. Marston, 1991:

Unfolded optical glory of spheroids: Backscattering of laser light from freely rising spheroidal air bubbles in water. Appl. Opt., 30, 3429-3442.

Arnott, W.P., H.E. Bass and R. Raspet, 1991:

General formulation of thermoacoustics for stacks having arbitrarily-shaped pore cross-sections. J. Acoust. Soc. Am., 90, 3228-3237.

Arnott, W.P., J.M. Sabatier and R. Raspet, 1991:

Sound propagation in capillary-tube-type porous media with small pores in the capillary walls. J. Acoust. Soc. Am., 90, 3299-3306.

Arnott, W.P., Y. Dong, J. Hallett and M.R. Poellot, 1994:

Role of small ice crystals in radiative properties of cirrus: A case study, FIRE II, 22 November 1991. J. Geo. Res., 99, 1371-1381.

Mitchell, D.L. and W.P. Arnott, 1994:

A model predicting the evolution of ice particle size spectra and radiative properties of cirrus clouds. Part II: Dependence of absorption and extinction on ice crystal morphology. J. Atmos. Sci., 51, 817-832.

Arnott, W.P, Y. Dong and J. Hallett, 1995:

Extinction efficiency in the IR (2 µm to 18 µm) of laboratory ice clouds: Observations of scattering minima in the Christiansen bands of ice. Appl. Opt., 34, 541-551.

Arnott, W.P., Hans M. Moosmuller, Robert E. Abbott, and Michael D. Ossofsky, 1995:

Thermoacoustic enhancement of photoacoustic spectroscopy: Theory and measurements of the signal to noise ratio. Rev. Sci. Instrum. 66, 4827-4833.

Arnott, W.P., Jay A. Lightfoot, Richard Raspet, and Hans Moosmuller, 1996:

Radial wave thermoacoustic engines: Theory and examples for refrigerators and high-gain narrow-bandwidth photoacoustic spectrometers. J. Acoust. Soc. Am. 99, 734-745.

Arnott, W.P., C. Schmitt, Y. Liu, and J. Hallett, 1997:

Droplet size spectra and water vapor concentration of laboratory water clouds: Inversion of FTIR (500-5000 cm^-1) optical depth measurement. Applied Optics 36, 5205-5216.

Yang, P., K.N.Liou, and W.P. Arnott, 1997:

Extinction efficiency and single-scattering albedo for laboratory and natural cirrus clouds. J. Geophys. Res. 102, 21, 825-21, 835.

Sassen, K., W.P. Arnott, J.M. Barnett, and S. Aulenback, 1998:

Can cirrus clouds produce glories. Appl. Opt. 37, 1427-1433.

Liou, K.N., P. Yang, Y. Takano, K. Sassen, T.P. Charlock, and W.P. Arnott, 1998:

On the radiative properties of contrail cirrus. Geophys. Res. Lett. 25, 1161-1164.

Moosmuller, H, W.P. Arnott, C.F. Rogers, J.C. Chow, C.A. Frazier, L.E. Sherman, and D.L. Dietrich, 1998:

Photoacoustic and filter measurements related to aerosol light absorption during the Northern Front Range Air Quality Study (Colorado 1996/1997). J. Geophys. Res. 103, 28149-28157.

Liu Y., W.P. Arnott, and J. Hallett, 1998:

Anomalous Diffraction Theory for Arbitrarily Oriented Finite Circular Cylinders and Comparison with Exact T-Matrix Results. Appl. Opt. 37, 5019-5030.

Lightfoot, J.A., W.P. Arnott, H.E. Bass, and R. Raspet, 1998:

Experimental study of a radial mode thermoacoustic prime mover. J. Acoust. Soc. Am. 105, 2652-2662.

Liu, Y, W. P. Arnott, and J. Hallett, 1999:

Particle size distribution retrieval from multispectral optical depth: Influences of particle nonshpericity and refractive index. J. Geophys. Res. 104, 31, 753-.

Schmitt, C., and W.P. Arnott, 1999:

Infrared emission (500-2000 cm^-1) of laboratory ice clouds. J. Quant. Spec. and Rad. Transfer 63, 701-725.

Arnott, W.P., H. Moosmuller, and D.F. Rogers, 1999:

Photoacoustic spectrometer fro measuring light absorption by aerosols: Instrument description. Atmos. Env. 33, 2845-2842.