This implies that there was full convection from the surface to about 15,000 feet above sea level in the region, and environmental lapse rates were near or at the dry adiabatic lapse rate. (stormbruiser.com)
In the troposphere, temperatures decrease with height at the environmental lapse rate we mentioned above, i.e., -6.5 °C per kilometre -LRB--3.5 °F per 1,000 feet). (globalwarmingsolved.com)
This rate of change of temperature with height (or altitude) is called the «environmental lapse rate». (globalwarmingsolved.com)