Nonspherical extinction and absorption efficiencies.

Predictions concerning the scattering and absorption characteristics of electromagnetic radiation interacting with nonspherical particles are obtained by suppression of particle resonances (surface waves) in classical Mie scattering theory. The importance of the particle resonance phenomenon and thus the nonspherical corrections is related to the three classical variables n(i), n(r), and x, the imaginary and real components of the index of refraction and the size parameter, respectively. The resonance phenomenon becomes increasingly restricted to small values of x as n(r) increases. For solar wavelengths and cloud size particles resonance phenomenon may be neglected for n(r) greater, similar 2. As n(r), decreases the effect of nonsphericity becomes increasingly significant to both scattering and absorption. For n(r) less, similar 2.0 and n(i) approximately 10(-5), suppression of particle resonances in Mie theory predicts increases in absorption efficiency of several orders of magnitude in the region of the absorption peak.