* The difference between weather and climate is a measure of time. * Weather is what conditions of the atmosphere are over a short period of time * Climate is how the atmosphere "behaves" over relatively long periods of time.

* Latitude – determines temperature and precipitation (planetary winds), as distance from the equator increases, average annual temperature decreases. * Altitude – high altitude = cool climates, and drier, adiabatic cooling of air as it moves up.

* Oceans and large bodies of Water – bodies of water regulate temperatures and add moisture to the air. * Ocean Currents – temperature of currents determines temperature of nearby land mass

OROGRAPHIC EFFECTS * Topography – Mountain ranges: windward vs leeward sides of mountains – different climates. * Why? Air mass rises and cools adiabatically, clouds form, it rains. Air cools due to expansion…as it comes down the other side, warms adiabatically due to compression and dries out.

* Planetary Wind Belts – Wind patterns are caused by the Coriolis effect – causing a deflection to the right in NH * Prevailing Winds- determine the source of the air mass (temperature and moisture content) * Vegetation – determines absorption and reflection of insolation and rate of transpiration

* Monsoons: Periods of severe rains – result of shifting winds.  Typical Storm Tracks – west to east across US, northward from Gulf States.  Hurricanes move off the coast of Africa westward and northward.  Jet Stream Winds – currents of very fast winds that flow in the upper atmosphere.

El Nino and La Nina * El Nino – water warms, causing extra rainfall in Eastern Pacific and severe droughts in Western Pacific. * Jet Stream is offset causing global weather pattern disruptions. * La Nina creates the opposite effect.

* Primary elements of climate: temperature and precipitation. * A climate is classified on whether it is humid or arid and relates to the P/Ep ratio. Where P= precipitation and Ep = Evapotranspiration * They are: Polar, Dry, Humid Tropical, Moist Mid-Latitude, Highlands.

* When you divide precipitation (P) by evapotranspiration (Ep) the number you obtain is used to determine climate type. * P/Ep> 1.2 = humid * P/Ep < 0.4 = Arid * 0.8 to 1.2 = sub-humid * 0.4 to 0.8 = semi-arid

Water Budget is the available water in a geographic region. * Factors that affect the local water budget include: 1. Temperature 2. The presence of vegetation 3. Wind 4. The amount and duration of rainfall.