Dust aerosol height estimation: A synergetic approach using passive remote sensing and modelling

In this paper, a simple methodology for deducing a proxy index inferring on the dust aerosol layer height (in the atmosphere) has been presented by exploiting the dependence of the relationship between Aerosol Index (AI) and aerosol optical thickness (AOT) on the aerosol altitude. For the purpose, OMI-AI and GOCART model simulated dust AOT values over northern Arabian Sea are used. Northern Arabian Sea has been chosen as the study grid due its frequent vulnerability to the Arabian dust storms. Temporal variations in the dust AOT and AI values over the study region are discussed. Linear regression to the scatter plots between the dust AOT and AI values revealed the qualitative information on the dust layer altitudes. Results indicated that dust aerosols over the study region attain their highest altitude during July, August months. CALIOP aerosol sub-type measurements are examined in order to support the results obtained. Expansion of the present technique on inferring the spatio-temporal variability in the aerosol altitude over dust storms prone regions can be highly advantageous in fine tuning the regional dust aerosol radiative forcing calculations.