FM-120 and Standard Fog Collector Measurements of Mesh Efficiency

Abstract:

The purpose of our study is to deduce the efficiency of standard fog collectors deployed at a location in Marina, California that is subject primarily to coastal advective fog. Fog collection efficiency will be determined by evaluating the liquid water content (LWC) of the air both fore and aft of a standard fog collector using a pair of FM-120 fog droplet spectrometers. Past research has attempted to calculate this parameter through formulaic derivations based on the fog mesh characteristics, the wind speed and the fog droplet spectrum. Our research uses direct LWC measurements obtained from a dual pair FM-120 fog droplet spectrometers. To the best of our knowledge, this is the first time such a study has been conducted.

In July, 2020, we deployed two FM-120 droplet spectrometers, one fore and one aft of one of three standard fog collectors based on Schemenauer’s design. Two of them were fitted with double-layer Raschel mesh and one with German FogHaTin mesh. The results, accompanied by coincident meteorological observations, will provide a unique insight into the capacity of different types of mesh to collect and deposit fog droplets as liquid water in a variety of fog and wind regimes.