Global Climate Systems GPH 111

Local Climate Conditions:  Monsoon (summer rain)  Frontal (winter rain)  Monsoon (summer rain)  Frontal (winter rain)

 Monsoon means a “change in the winds”  Winds shift from “West” to “East”  Azores High Pressure moves westward, driving winds off the Gulf of Mexico and California into Arizona.  Monsoon means a “change in the winds”  Winds shift from “West” to “East”  Azores High Pressure moves westward, driving winds off the Gulf of Mexico and California into Arizona. 1. Summer Monsoons

1. Azores High Pressure

1. High Dew Points  Arizona’s monsoon starts when three days in a row have dew points 55 degrees or higher.  Moisture comes from the Gulf of Mexico and Gulf of California.  Lifting Mechanisms: Convection, Orographic, Downdraft  Need to lift the air to cool it and generate rain  Arizona’s monsoon starts when three days in a row have dew points 55 degrees or higher.  Moisture comes from the Gulf of Mexico and Gulf of California.  Lifting Mechanisms: Convection, Orographic, Downdraft  Need to lift the air to cool it and generate rain

1. Lifting Mechanisms: Convection

1. Lifting Mechanisms: Orographic

1. Lifting Mechanisms: Downdraft

2. Winter Frontal Systems  Dominant air masses: Warm Moist to the south Cold and Dry to the north  Low pressures from the jet stream spin counter-clockwise  This forces the warm moist air over cold dry air, causing storms  Dominant air masses: Warm Moist to the south Cold and Dry to the north  Low pressures from the jet stream spin counter-clockwise  This forces the warm moist air over cold dry air, causing storms

2. Winter Frontal Systems

3. Phoenix Climate graph

Major Climate Components:  Insolation  Temperature  Air Pressure  Wind Belts  Air Masses  Precipitation  Insolation  Temperature  Air Pressure  Wind Belts  Air Masses  Precipitation

What controls Temperature 1)Latitude* – Lower latitude warmer and more moderate, higher latitude cooler and more extreme 2) Continentality* – Close to ocean more moderate, far from ocean more extreme

The importance of Latitude…

And Continentality… Where coastal regions experience moderate temperatures compared to locations inland because it is much harder to change the temperature of water compared to land. Where would you rather vacation, Wichita or San Diego?

Reasons for… Dry seasons High pressure systems* 1) High pressure systems* 2) Bounded by cool ocean * currents * Reasons for… Wet seasons (Review) Convergent* 1) Convergent* – ITCZ Convection* 2) Convection* – Heating Frontal* 3) Frontal* – Cold Fronts Wet versus Dry…

Desert Causal Elements: 1) High Pressure Systems Great Victoria Desert, AU

Desert Causal Elements: 2) Bounded by cool ocean currents Atacama Desert, Chile

 Tropical [A] (tropical latitudes mild year round) - rain forest (rainy all year) - monsoon (> 6 months rainy) - savanna (< 6 months rainy)  Mesothermal [C] ( subtropics / mid-latitude mild winter ) - humid subtropical (hot summers) - marine west coast (warm to cool summers) - Mediterranean (dry summers)  Microthermal [D] (mid / high latitude cold winter ) - humid continental (hot to cool summers)  Tropical [A] (tropical latitudes mild year round) - rain forest (rainy all year) - monsoon (> 6 months rainy) - savanna (< 6 months rainy)  Mesothermal [C] ( subtropics / mid-latitude mild winter ) - humid subtropical (hot summers) - marine west coast (warm to cool summers) - Mediterranean (dry summers)  Microthermal [D] (mid / high latitude cold winter ) - humid continental (hot to cool summers) Climate Classification Categories Letters refer to Koppen System  Deserts [B] (permanent moisture deficits) - arid deserts (tropical and midlatitude)  Deserts [B] (permanent moisture deficits) - arid deserts (tropical and midlatitude)

Af Tropical - Rain Forests [Af]

Am Tropical - Monsoon Climates [Am]

Aw Tropical - Savanna Climates [Aw]

Cfa Mesothermal - Humid Subtropical [Cfa] (Hot-Summer Climates)

Cfc Mesothermal - Marine West Coast [Cfc] (southern hemisphere)

Cwb-a Mesothermal – Mediterranean [Cwb-a] (dry summer)

Dfa-wa Microthermal - Humid Continental [Dfa-wa] (hot summer climate)

BWk Desert - Midlatitude [BWk] (cool desert climate - arid)

Things to know:  How do Arizona’s monsoons work to give us rain in the summer?  Arizona receives rain from frontal systems in the winter (already covered this earlier) temperature and precipitation  Know the two major components of climate: temperature and precipitation  The two controls on temperature  Two reasons for a dry season  Three reasons for a wet season locations  Example locations of the climate classification categories covered, why they are dry and why they are wet, and why they have large variations or little variation in temperature  How do Arizona’s monsoons work to give us rain in the summer?  Arizona receives rain from frontal systems in the winter (already covered this earlier) temperature and precipitation  Know the two major components of climate: temperature and precipitation  The two controls on temperature  Two reasons for a dry season  Three reasons for a wet season locations  Example locations of the climate classification categories covered, why they are dry and why they are wet, and why they have large variations or little variation in temperature Help: Chapter CS