$d_c$	Collision diameter, $\mathrm{m}$
$d_g$	Gyration diameter, $\mathrm{m}$
$d_m$	Mobility diameter, $\mathrm{m}$
$d_p$	Primary particle diameter, $\mathrm{m}$
$D_f$	Fractal dimension
$D_{fm}$	Mass-mobility exponent
$k_B$	Boltzmann constant, ${\mathrm{m}}^2\mathrm{kg}/{\mathrm{s}}^2/\mathrm{K}$
$k_n$	Fractal prefactor
$k_m$	Mass-mobility prefactor
$Kn$	Knudsen number
$m_{Ag}$	Single agglomerate mass, $\mathrm{kg}$
$n_p$	Number of primary particles per agglomerate
$N_{Ag}$	Agglomerate number density, ${\mathrm{m}}^{-3}$
$P$	Gas pressure, $\mathrm{kg}/{\mathrm{s}}^2/\mathrm{m}$
$R$	Universal gas constant, ${\mathrm{m}}^2\mathrm{kg}/{\mathrm{s}}^2/\mathrm{mol}/\mathrm{K}$
$t$	Time, $\mathrm{s}$
$T$	Temperature, $\mathrm{K}$
Greek letters
$\beta$	Collision frequency, ${\mathrm{m}}^3/\mathrm{s}$
$\rho$	Bulk aerosol density, $\mathrm{kg}/{\mathrm{m}}^3$
${\rho }_{eff}$	Effective aerosol density, $\mathrm{kg}/{\mathrm{m}}^3$
${\sigma }_{g,m}$	Geometric standard deviation of $d_m$ distribution
${\sigma }_{g,p}$	Geometric standard deviation of $d_p$ distribution