The influence of wind effects on local atmospheric corrosivity was measured and modeled. Six sets of CLIMAT units were placed among devices that provided various degrees of wind sheltering near
a deiced highway. Although each set was exposed to the same relative humidity, there was a 34-fold difference between the average mass loss of the most wind-protected and the least wind-protected sets. This is consistent with the concept that atmospheric corrosion rates depend primarily on salt aerosol deposition rates, which in turn depend on local wind velocity and turbulence patterns. Therefore barriers that reduce the wind velocity and turbulence intensity reduce aerosol deposition rates and consequently corrosivity rates. Detailed modeling of the wind flow patterns around two of the CLIMAT sets confirmed that the corrosivity differences were due to aerosol deposition effects. Terminology
could be modified to better reflect the localized nature of atmospheric corrosivity. It is suggested that macrocorrosivity refer to the characterization of an area that is on the scale of kilometres such as a city or county; that microcorrosivity refer to the characterization of locations that are on the scale of meters such as different sites near a building or vehicle; and that nanocorrosivity refer to characterizing spots
that are on the scale of centimetres.
Keywords: local atmospheric corrosivity, airflow modeling, CLIMAT coupons, microcorrosivity, nanocorrosivity