Abstract
To overcome the general lack of information on variations of local atmospheric mixing in space and time over an urban area, a simple technique of searchlight probing was developed and tested.
A searchlight beam is directed at various angles into an urban atmosphere and observations of beam intensity variations — which correspond with space variations of aerosol concentrations — are photographed. Photographic sequences of beam intensity show that aerosols are frequently concentrated in low-altitude stratified layers. These layers assume many different heights, thicknesses, movements and lifetimes.
The large space and time variations of stratified layers revealed by searchlight probing, together with known causes and implications of aerosol layers, are discussed. The results of using searchlight probing in this study point out the need to measure a city's atmospheric mixing structure on both an individual and a periodic basis. Searchlight probing is a practical measuring technique at a low cost.
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Gschwandtner, G., Pengelly, L.D. Measurement of the frequency and location of stratified aerosol layers using a searchlight probing technique. Boundary-Layer Meteorol 14, 361–368 (1978). https://doi.org/10.1007/BF00121045
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DOI: https://doi.org/10.1007/BF00121045