R ELATIONSHIPS Weather Variables

A IR P RESSURE & A IR T EMPERATURE As air temperature decreases, the air pressure increases Temp. decreases, slower, closer, more dense As air temperature increases, the air pressure decreases Temp. increases, faster, spread out, less dense As air pressure increases, the air temperature increases Closer, hit each other more, more heat As air pressure decreases, the air temperature decreases Farther apart, don’t hit each other, less heat

A IR P RESSURE AND HUMIDITY Water vapor is much lighter than other gases in the atmosphere. The higher the humidity, the lower the air pressure Increase water vapor, lower weight molecules push out heavier molecules, lower pressure The lower the humidity, the higher the air pressure

A IR TEMPERATURE AND HUMIDITY Cold air can hold less water vapor than warm air. Warm air can hold more water vapor than cold air. If the temperature increases, the relative humidity will decrease Hotter, has the capacity to hold more, % decreases If the temperature decreases, the relative humidity will increase Hotter, less capacity to hold, % increases As air temperature approaches the dew point, precipitation becomes more likely

A IR PRESSURE AND WINDS Winds blow from regions of high air pressure to regions of low pressure

G LOBAL WINDS / PLANETARY WINDS Air currents are made from rising warm air and sinking cold air around the Earth. Global/planetary winds are created by convection currents and the rotation of the Earth. Coriolis Effect: curving path of winds because of the Earth’s rotation In the northern hemisphere everything is deflected to the right In the southern hemisphere everything is deflected to the left

C LOUD AND PRECIPITATION FORMATION How do clouds form? Clouds and precipitation are formed when air is cooled below its dew point and water vapor condenses into tiny water droplets or ice crystals Sublimation: the change of phase from a gas directly to a solid Fog: is a cloud whose base is at ground level. It forms when moist air at the ground is cooled below its dew point. What good things do precipitation do for us? Precipitation removes dust/dirt and many pollutants from the atmosphere.