Wind Wind – the horizontal movement of air from an area of high pressure to an area of lower pressure -caused by the differences in air pressure -Differences in air pressure: caused by the unequal heating of the atmosphere Measured with an anemometer Wind chill factor: the increased cooling a wind can cause “With the wind chill factor is feels like -10 degrees Fahrenheit outside”

Local Winds Local winds are caused by the unequal heating of the Earth’s surface within a small area Two Types of Local Winds: Sea Breeze: a local wind that blows in from an ocean or lake - It takes more energy to warm up a body of water than it does to heat up an equal area of land Land Breeze: the flow of air from land to a body of water - Land cools more quickly than water, so the air over the land becomes cooler than the air over water

Global Winds Global winds are winds that blow steadily from specific directions over long distances. See them in Action! art/global_winds/index.html Code:cfp-4023 Coriolis Effect: winds curve based on Earth’s rotation

Global Wind Belts Doldrums: a calm area at the equator where warm air rises (little to no wind) Horse Latitudes - Areas of no wind occurs at 30  N & 30  S, air stops moving toward the poles and sinks. Trade winds: winds that blow from the horse latitudes toward the equator Named for ships moving cargo on these winds

Prevailing Westerlies: blow wind away from the horse latitudes – happens between 30  - 60  Polar Easterlies: blow cold air away from the poles Jet Streams: bands of high speed winds that travel north to south along a wavy path

Hydrologic Cycle (The Water Cycle)

The hydrologic cycle (Water Cycle): The continuous movement of water on, above, and below the surface of the earth. The hydrologic cycle (Water Cycle): The continuous movement of water on, above, and below the surface of the earth. Evaporation: process by which water molecules in liquid water escape into the air as water vapor (gas) We usually think about oceans, but clouds also evaporate. Transpiration – Water released by plants into air. Condensation: Water vapor (gas) turns back to a liquid. (Energy needs to be removed) – - Cloud formation.

Precipitation: Water that is so heavy it falls as liquid / solid. Precipitation can also be a solid in the form of snow, hail, or ice pellets. Humidity: a measure of the amount of water vapor in the air Relative humidity: % of water vapor in the air compared to the max amount of water vapor the air can hold at a certain temperature – measure with PSYCHROMETER

Steps of the Water Cycle ycle.htmlhttp:// ycle.html - Flash animation Evaporation Transpiration Condensation Precipitation Surface runoff

Surface run-off: The water flow which occurs when soil is full to capacity and excess water travels over the land. Surface run-off: The water flow which occurs when soil is full to capacity and excess water travels over the land. Storage of water in vegetation. – Plants soak up and hold water. They are very good flood preventers.

Cloud Formation Clouds form when water vapor in the air condenses to form liquid water or ice crystals Dew point: the temperature at which condensation begins o If the dew point is above freezing, the water vapor forms water droplets o If the dew point is below freezing, the water vapor may change into ice crystals

Types of Clouds Cirrus Clouds: wispy, feathery clouds – result of low temperature at high altitudes (has the appearance of a horse’s tail) Cumulus Clouds: fluffy, rounded piles of cotton – identification of fair weather (sunny day) - Cumulonimbus clouds: towering clouds with flat tops that produce thunderstorms (nimbus means rain) Stratus Clouds: flat spread out layers – usually cover most of the sky, usually gray in color - Nimbostratus clouds: thickened stratus clouds that produce rain or snow