Dry and wet deposition of acid rain
When the particles are deposited by wet deposition, the particles are scavenged by snow, rain drops, and other methods of precipitation. In dry deposition, the causes of the deposition can be sedimentation, interception, impaction, diffusion, turbulence, or one of several other causes.
There are two types of acid rains:
(1) Dry Deposition: In dry weather areas, the acid chemicals may become incorporated into dust or smoke and fall to the ground through dry deposition, sticking to the ground, buildings, homes, cars, and trees. Dry deposited gases and particles can be washed from these surfaces by rain storms, leading to increased runoff. This runoff water makes the resulting mixture more acidic. About half of the acidity in the atmosphere falls back to earth through dry deposition.
(2) Wet Deposition: Wet deposition refers to acidic rain, fog, and snow. If the acid chemicals in the air are blown into areas where the weather is wet, the acids can fall to the ground in the form of rain, snow, fog, or mist. As this acidic water flows over and through the ground, it affects a variety of plants and animals. The strength of the effects depends on several factors, including how acidic the water is; the chemistry and buffering capacity of the soils involved; and the types of fish, trees, and other living things that rely on the water.