Sea-salt aerosol forecasts compared with daily measurements at the island of Lampedusa (Central Mediterranean)

Abstract

Operational regional sea-salt aerosol forecasts have been produced on a daily basis since February 2006 over the open sea in the Mediterranean, where sea-salt aerosol concentrations and their impact on the Mediterranean weather and climate could be significant under strong winds. In order to evaluate the model performance, the numerical simulations of sea-salt aerosol (SSA) were compared with sea-salt ground-based measurements taken at the tiny Mediterranean island of Lampedusa, Italy. Considerable effort was made in order to collect and analyze SSA measurements on a daily basis, during the two-year period from 2007 to 2008. In Lampedusa, the conditions of SSA measurements are considered similar to those in the open sea, given the small dimensions of the island. As estimated for all 380days used in the analysis, model-vs.-measurement comparisons at Lampedusa show a relatively high correlation of 0.7 between model data and measurements; a rather low mean bias of −0.5μg/m3; and a mean normalized bias less than 20%. Therefore, the model was capable of producing reasonable SSA concentrations and their day-to-day variations over the open sea.