Low-pressure area

Air Pressure The weight of the air above Earth?s surface Thanks to gravity, the atmosphere has weight. What affects air pressure? Altitude ? air pressure decreases the higher you go up 2 miles up Sea level Decreasing Air Pressure Higher Concentration of air molecules Gravity forces most air molecules to remain close to Earth?s surface Cold air is more dense than warm air Cold air has higher air pressure because the molecules are closer together v v COLD HOT Warm air has LESS air pressure because molecules are farther apart COLD HOT Which air mass can hold more water vapor? v v COLD HOT v v c COLD HOT Air Molecule Water Molecule Warmer air can hold more water molecules than cooler air