Probability Definition. The probability of an event is a number between $0$ to $1$ which measures the chance of that event occurring. The likelihood of the occurrence of the event increases as the probability varies from $0$ to $1$. The probability of the occurrence of an impossible event is $0$ and that of a certain to occur event is $1$.
As altitude increases, air pressure decreases. Gravity causes the atmosphere to become heavier the closer you are to the ground. The atmosphere may seem weightless but all the â¦ air molecules add up to a tremendous amount of mass.
Temperature increases as you gain altitude in the stratosphere and the thermosphere. Temperature decreases as you gain altitude in the troposphere and mesosphere. Air temperature varies in complicated ways with altitude. Near the Earth's surface, air gets cooler the higher you climb. As you climb a mountain, you can expect the air temperature to decrease by 6.5 degrees C for every 1000 meters you gain. This is called the standard (average) lapse rate. If air temperature is 30 degrees C at sea level as shown above, you can expect it to be around 10.5 degrees C at air altitude of 3000 meters because of the lapse rate. Plan an expedition! You are going to climb Mount Audubon in Colorado today!