Chapter 9

Influences Sun angle and length of day
* critical to climate: 1) intensity of radiation 2) length of day related to teh Earth-Sun geometric relationship

Influences flow of air and position of high and low pressure systems
* flow predictable w/distinct pressure systems associated w/ specific zones
    = Results w/
    * ITCZ = heavy or persistent precipitation
    * STH = dry
* Midlatitude cyclones = highly variable weather from day to day

* Large water bodies moderate temperature, influence air flow, supply water vapor
* proximity to water impact temp & direction of airflow

* interior of continent - annual temp fluctuates
* ocean - annual temp moderate

* Evaporation of large amount of water vapor = associated with warm oceans
* cold oceans = drying effect on adjacent continent location

Position of Earth in orbit influences amount of radiation received

A measure of the maximum possible water loss from a given land area assuming sufficient water is available.
* estimated of the amount of water used by plants with an unlimited water supply.
* ET increases with increasing temp, daylight length, wind strength and decreases when humidity increases
* changes take place due to factors such as insolation and vapor gradient.

The quantity of water actually removed from a given land area by evaporation and transpiration.

Tropical Rain Forest (Af)
Tropical Monsoon (Am)
Tropical Savanna (Aw)

Hot Low-Latitude Desert (BWh)
Cold MidLatitude Desert (BWk)

Hot Low-Latitude Steppe (BSh)
Cold MidLatitude Steppe (BSk)

Humid Subtropical Hot-Summer (Cfa, Cwa)
Marine West-Coast (Cfb, Cfc)
Mediterranean Dry-Summer (Csa, Csb)

Humid Continental Hot-Summer (Dfa, Dwa)
Humid Continental Mid-Summer ((Dfb, Dwb)
Subarctic (Dfc, Dwc, Dwd)

Tundra (ET)
Ice Cap (EF)

Highland (H)

Purpose is to id certain characteristics such as temp & precipitation that have definable regional patterns.
* Recognized the relationship b/w major vegetation regions and regional climate characteristics. 
* contains six major climate groups, broken into as many as 23 subcategories.
* Based on average monthly temp & precip and annual precipitation
* describes regional climate conditions but ignores local factors ie wind speed, cloud cover
* ITCZ - tropical - wet 
* STH - 30 N/S - drier

A graphical representation of climate that shows average annual precipitation and temperature characteristics by month.

Indirect evidence of an event. For example, fossil pollen is a proxy indicator of climate change because vegetation reflects climate.

The dating of past events and variations in the environment and climate by studying the annual growth rates of trees.

Periods of time that have distinct O-18/O-16 ratios, which are used to reconstruct prehistoric climate change.

The theory that best explains Pleistocene glacial/interglacial cycles through long-term variations in Earth's orbital eccentricity, tilt, and axial precession

Environmental changes caused by humans

Carbon-based energy sources, such as gasoline and coal, that are derived from ancient organisms.

* Mountains affect precipitation on windward and leeward sides, influence air flow.
* Windward side - heavy precipitation b/c air cools adiabatically
* Leeward side - (rain shadow) due to descent of air and associate adiabatic warming

* Topo regions influence airflow result in Chinook winds & cool-air drainage

Critical in character & distribution of global climates for two reasons related to Sun angle.

1. #of hours of sunlight in a day change many places over year.
2. isolation & temp highly variable b/w winter and summer  - tropical regions very little different, reflected in the relatively consistent temp & precipitatin of tropical climates
   

* Subfield of Geography
* Study of spatial/geo distribution & the character of Earth's climate

Study long-term temp & precipitation patterns.
* Important for agriculture, architecture, ecology, forestry, econmics
* Important b/c climate influences human behavior and nature processes

Study of short atmospheric phenomena ie. thunderstorms ( day to day weather in particular place)

Environmental changes caused by humans

System focuses on the local scale and is used frequently in the US to assess soil moisture as they relate to vegetation and agriculture.
* Based on concept of (potential ET) and (Actual ET)
* Identifies three basic climate zones: Low-Latitude, Mid-Latitude and High-Latitude
* Subdivided on basis of length of time and by what amount, actual ET falls below Potential ET

* Not used elsewhere in the world - instead Koppen climate classification system is used.