Rain breeds more rain over ploughed land

摘要

Rain cleans the air, right? Wrong. On ploughed fields at least, it flings up millions of microscopic organic particles - the remains of dead plants and animals. This rainfall-induced haze may help to seed clouds and generate more rain. Currently it is assumed that most airborne particles are lofted up by the wind, sea spray, or human activities such as tilling. Last year, however, scientists showed - by filming artificial rain in the lab - that rainfall could stir up particles from soil.