function [Size_aero] = GeometricD2AerodynamicD(Size_geo, rou_dust)
% [Size_aero] = GeometricD2AerodynamicD(Size_geo, rou_dust)
% Input a geometric size "Size_geo", with its density "rou_dust" (unit:
% kg/m^3), output its corresponding aerodymanic size "Size_aero"

% parameter define
rou_water = 1000; % water density, in unit of kg/m^3
kai = 1.4; % the dynamic shape factor (Kok et al., 2014; 2017)

Size_aero = Size_geo/sqrt(kai*rou_water/rou_dust); 

end