Let's look more closely at how the air changes temperature when it rises or drops. We know that warm air rises, and when it rises it becomes cooler. If you remember that, you can reason your way through a lot of meteorology. Adiabatic heating and cooling implies a change in temperature of the parcel of air without gain or loss of heat from outside the air parcel. Adiabatic processes are very important in the atmosphere, and adiabatic cooling of rising air is the dominant cause of cloud formation.
Lapse Rates
For the atmosphere, the drop in temperature of rising, unsaturated air is about 10 degrees C/1000 meters (5.5 F per 1000 feet) altitude. If a parcel of air is at 24 C at sea level, and it rises to 1000 meters, its temperature will go down to 14 C. If it goes up to 2000 meters, its temperature will go down to 4 C.
What will its temperature be at 3000 meters? 1_________________
This rate of temperature change of unsaturated air with changing altitude is called the dry adiabatic lapse rate: the rate of change of the temperature of rising or subsiding air when no condensation is taking place (we'll talk about the condensation part shortly).
If the air subsides, it also changes temperature. It warms up, and it is warming up at the dry adiabatic lapse rate. So, if the air at 4000 meters altitude has a temperature of -10 C, and it subsides to 3000 meters, its temperature will warm up to 0 C. If it continues to subside, then at 2000 meters, its temperature will be 10 C. At 1000 meters, its temperature would be 2______________
Make sure you notice that we are talking about moving air (rising or subsiding), not still air. The change in temperature of still air (that is, air that is not rising or subsiding) follows the Environmental Lapse Rate, which varies considerably, but averages about 6.5 C/1000 meters (3.6 F/1000 feet). In still air, if you went up in a hot air balloon, carrying a thermometer and taking the air temperature