Chapter 19 Atmospheric Pressure Air Pressure High Pressure Low Pressure The weight of the atmosphere Good weather Bad weather

Barometer Instrument used to measure atmospheric pressure Either in mmHg or in millibars

Dry Air…….. Humid Air………. Heavy Lighter because the water molecules push the nitrogen and oxygen apart

IsobarLines that connect points of equal PRESSURE

Low pressure area High pressure area Air moves counterclockwise and in toward the low Air moves clockwise and out away from the High pressure area

WIND!!!!!The movement of air from an area of high to low pressure

Coriolis Effect Because the earth rotates to the East, winds on earth get deflected or turned to the west

Jet Stream

Land & Sea Breezes Warm breeze at night and a cool breeze during the day due to ….. …the unequal heating of land and water

Anemometer Wind Vane Measures wind speed Measures the DIRECTION of the wind

Chapter 21 Climate is the long-term weather of an area Weather changes day to day; climate changes once every couple of centuries. Virginia’s Climate is MILD.