The Nature, Amplitude and Control of Microwave Attenuation in the Atmosphere

Abstract

Microwave (MW) attenuation plays a critical role in constructing communication networks. It also can be a useful tool in the meteorological and optical communities for radar and microwave imaging applications. Because most atmospheric constituents (large hydrometeors being an exception) are very small compared to MW wavelengths, data analysis is typically performed using conventional Rayleigh theory; however, some anomalous observations have proven difficult to explain. We present the results of the first systematic numerical computations over a wide range of aerosol properties. We demonstrate that it is possible to perform mass computations of aerosol loading, which is an important climate parameter. We show that discrepancies found between theoretical predictions and observations can be attributed to the effect of the expected charge acquired by the dust particles through contact electrification occurring in dust storms. While frequencies below 10 GHz normally allow for long-distance signal transmission, the charge-induced resonances in particles can preferentially amplify the low-frequency MW attenuation by a factor of 10 or more, depending on their surface electric potential. In addition, we find electrically charged particles dispersed in a local atmosphere as a potential tool for the controlled manipulation of MW attenuation.