Measurements of atmospheric sea salt concentrations in Hawaii using a Tala kite

Abstract

An inexpensive and convenient method to sample sea salt concentrations in the lowest few hundred meters of the atmosphere was tested in Hawaii. The string to a Tala kite flying at about 150 m was intersected by thin steel wires on which sea salt collected during one hour long flights. Measurements were taken at two beaches and inland of one of them. Sampled concentrations compared well with same day aircraft and tower measurements. A surf zone upwind of one of the beaches produced surface concentrations as high as 250 μg m^-3, while the other beach without such a zone had less than 35 μg m^-3. The high concentrations at the surf beach extended above 145 m. Concentrations at 100 m correlated best to wind speed at this level and less so to previous two-day mean upwind surf condition, cloudiness and shower activity. Simultaneous measurements at and inland of the surf beach showed the effects of boundary layer mixing with a much more uniformly decreasing concentration profile as opposed to a steep decrease up to about 40 m at the beach.