Pressure Changes with Altitude
State the relationship between height (altitude) and pressure Pressure reduces in half for each ______ km 5 1% of the atmosphere 10% of atmosphere Air Pressure Is Proportional to Density (density is how packed the molecules are per unit area)
At HIGH altitudes, the air is thin, Pressure is less At LOW altitudes, near the surface, there are more air molecules, so pressure is greater. Factors that Affect Air Pressure
Density (altitudeor elevation) Temperature Humidity (water vapor)) Weatherbug graph activity Pressure Changes with Temperature
Warm air molecules have a lot of energy, are widely spaced apart less dense, and exert less, LOW pressure. Cold air contains slow moving molecules that are packed closely together (very dense) and exert HIGH pressure. Air Pressure and Aviation
Altimeter: measures altitude by detecting change in air pressure Temperatures vary due to UNequal heating of earths surface
Earths seasonal orbit around the Sun Thickness of Earths atmosphere Angle of the sun 23.5 degree tilt on axis Temperature changes with Humidity (water vapor in the air)
Increase in water vapor (humidity) causes Air:N2 _____andO2 _______ 14 x x 2= 60 Water vapor: H2O 2 Hydrogen ____Oxygen ______ 1 x =18 air to be LESS dense = less, LOW pressure Relative Humidity and air Pressure Upper atmosphere winds (Jet Stream) Upper Air-flow patterns cause Surface High and Low pressure
https://www.youtube.com/watch?v=aiYyCurh_SU WGN explains Convergence and Divergence
Air converges, piles-up and is forced upward. More air in a taller column Causes vertical clouds and precipitation Cold air sinks, and is forced to spread-out at the surface. No clouds form clear, fair weather http://darktimeschronicle. wordpress
Cyclone Anticyclone What direction is this cyclone rotating? in the Northern and Southern Hemispheres
Cyclonic Circulation in the Northern and Southern Hemispheres