Vertical Motion in the Atmosphere Jon, Ashley, Paige

Pre-Assessment Why does hot air rise?

Air Parcel Block of air with uniform temperature and pressure –Changes by rising, falling, and emitting/absorbing heat –If surroundings change, it will change too, but does not exchange heat

WARNING! Air does not rise “just because it’s warm”! Air that is warmer than its surroundings becomes buoyant and floats on top of cooler, denser air. This movement is known as convection

The Perfect Gas Law If air stays at a constant pressure, increasing the temperature will cause it to expand and become less dense

Relative Humidity Actual amount of water vapor in air Maximum amount of water vapor air can hold *at a specific temperature TO Compares -When it reaches 100%, it cannot hold any more water -Temperature and amount of water it can hold go up exponentially

Water Vapor Adding moisture to dry air causes it to become buoyant and rise! As water evaporates, it releases energy and warms the surrounding air Dew Point- Temperature at which air has to cool to reach 100% humidity *When air reaches dew point, it condenses into droplets (rain/snow)

Convergence When air masses clash, they push air upward –Example - in warm weather, this creates thunderstorms -If warm air is lifted high enough to reach its dew point, clouds will form. -If lifting forces are strong, the system will produce tall, towering clouds that can generate intense rain or snow storms. dense/cold warm Dew Point  CLOUDS!

Post-Assessment How does air rise?