Work out lapse rate instantly with clear inputs, formula shown and shareable results.
Lapse rate is the temperature fall per kilometre of altitude. Fourteen degrees over 2000 m is 7 C/km - between the saturated adiabatic rate of about 6 and the dry adiabatic 9.8, so the atmosphere is conditionally unstable: stable for unsaturated air but unstable once cloud forms. Negative rates are inversions, which trap pollution.
Environmental lapse rate
rate = (lower temp - upper temp) / height difference x 1000
Reference rates
dry adiabatic 9.8 C/km, saturated about 6 C/km, standard atmosphere 6.5 C/km
Unsaturated air resists rising but saturated air accelerates upward, so cloud once formed can develop into deep convection.
Because warm air above cold traps the surface layer, so pollutants cannot disperse upward and concentrations build.