Warm fog in eastern Mexico: A case study

Abstract

Measurements of microphysical characteristics of up-slope fog were carried out on a rural, mountain site in the Sierra Madre Oriental of eastern Mexico. Fog droplet-size distributions were obtained with a Forward Scattering Spectrometer Probe (FSSP) mounted on an instrumented ground-based vehicle. Data were gathered during one week in winter, but only the results for one day are presented here. Measured total droplet concentrations and liquid water contents (LWC) had average values of 150 cm^-3 and 0.44 g/m³, respectively, with mean volume diameters between 14 and 19 µm. Liquid water contents as high as 0.85 g/m³, with LWC peak diameters close to 30 µm, indicate that these fogs could have ideal characteristics for artificial water removal for human consumption. The potential for fog-water to be collected and used as a water supply in areas downwind of the study site, where average rainfall diminishes and semi-arid conditions prevail, is briefly discussed.