Why does weather occur only in the lowest layer of the atmosphere?
What we call weather is simply the movement of energy and moisture around the globe via air molecules. Due to Earth’s gravitational pull, most of the air molecules are located in the lowest seven miles of the atmosphere, called the troposphere. In fact, climbing to an elevation of just 3.3 miles will put about 50% of the Earth’s air molecules below you. The next layer up, from about 7 miles to 30 miles in altitude, is the stratosphere, a very stable layer with relatively few air molecules. Occasionally, the tops of very strong thunderstorms in the troposphere can penetrate the lower parts of the stratosphere. Meteorologists use weather balloons to measure weather condition in the troposphere. Learn more about weather balloons at this USA TODAY resource page.
