# Atmospheric dry deposition

Dry deposition is the dry transport of gases and particles from the atmosphere to the surface. Together with scavenging it is the ultimate sink process in the atmosphere. Dry deposition velocities depend on:​

• aerodynamic transport towards the surface by turbulence​

• transport across the laminar sublayer​

• particle chemical properties or size ​

• surface properties (smooth/rough, bare/vegetated, wet/dry)​.

Deposition velocities are uncertain as they are parameterizations based on relatively complex measurements. Particularly for the smallest particles few measurements are available.​

## Algorithms

 Surface properties (roughness, length, interceptor size) Atmospheric stability Size, shape, density of particle $$V_{d}= V_{8} + \frac{1}{R_{a}+R_{8}}$$ Resistance approach $$R_{a}= \frac{1}{\epsilon _{0}u_{*}(E_{B} + E_{IM} +E_{IN})R_{1}}$$ Surface resistance consisting of efficiencies for Brownian diffusion, impaction and interception $$V_{8}= \frac{\rho D^{_{p}^{2}}gC}{18\eta }$$ Gravitational settling velocity Visit the Atmospheric Deposition Model page.