Multiyear Measurements of the Aerosol Absorption Coefficient Near the Surface in a Small-Sized Urban Area in Portugal

Figure 3

Relative frequency distributions of the hourly (a) absorption coefficient, with the respective lognormal fitting, and (b) wind direction. Absorption coefficient as function of (c) wind speed (including the quartiles) and (d) wind direction.

(a)

(b)

(c)

(d)