Question

How are convection current set up in air?

Answer 1

convection currents are set up bcoz of density difference in air column . for example suppose land is very hot in daytime summer. the air nearest to land is heated up and its density decreases as compared to the air above it( high temperature means high volume and thus less density). as we know less dense materials are lighter than highly dense ones, so hot air will rise and the colder air will come down to tak its place. also the hot air after rising to a certain height gets cooled down and thus again become denser. and the cold air which has come down becomes hot. thus the cycle repets itself. this is called convection currents