Distributing the Sun’s Heat - WIND RULE #2 OF NATURE – Nature seeks balance (equilibrium) Create Wind is the movement of air from High pressure to Low pressure HOT air RISES COLD air SINKS

Precipitation – Nature’s Thermostat There are 3 basic causes for rain. They are: Convection – due to evaporation and cooling Sun’s energy causes surface water to evaporate and become humidity As the day cools off, the air cools and condenses, causing storms and rain Usually in tropical environments

Precipitation Frontal – due to changes in temperature Starts with warm, moist air at the surface and above As a cold front approaches, it stays low, forcing the moist air aloft This cools and condenses the air, creating rain on the “leading edge” of the front Usually in mid-latitudes where warm and cold air systems collide

Precipitation cont. Orographic – due to changes in elevation Moist air travels over land and approaches a steep rise in elevation As the air is forced up the side of the rise, the air cools, causing precip. on the “windward” side of the mountain As the (now dry) air continues over and down the “leeward” side of the mountain, it warms up and absorbs any available moisture, creating a “rain shadow desert” Found in areas of mountains or other rapid elevation change

Latitude Due to the Earth’s tilt, the amount of sun energy changes over the earth’s surface… Polar (High Latitude) zone – either mild temps. or extreme cold Temperate (Mid-Latitude) zone – seasonal, most varied climates Tropical (Low Latitude) zone – year-round direct sunlight, always hot RULE: The HIGHER the latitude, the COLDER the temps.

Altitude (Elevation) Higher elevation = thinner less air, therefore less air to hold heat makes it colder. RULE – The HIGHER the elevation, the COLDER the temperatures.

30 degree change in Houston 45 degree change in Denver Nearness to Water Land heats up and cools down QUICKLY. Water heats up and cools down SLOWLY. Therefore, water acts like a blanket… holding heat and releasing it slowly. This results in smaller daily and seasonal temperature changes near large bodies of water. “Coastal” areas are humid, “continental” areas are dry 30 degree change in Houston 45 degree change in Denver

Direction of Currents Global wind and ocean currents transfer heat and moisture around the world, and help carry moisture from the oceans to the land Warm water moving toward the land brings moisture (H2O) Warm water moving parallel to the coast brings heat, no H2O Cool water brings cool, dry air -> mild or desert climates

Reading check How do humans impact the atmosphere and how does this affect our lives?

Climate Zones Climate zones are divided into regions: The three climate zones of the world are the tropical zone, the temperate zone, and the polar zone. There are two key characteristics differences: Amount of moisture (rain), and Typical temperature range through the year These two characteristics are affected by balancing the effects of four factors: Latitude Altitude Nearness to water Direction of atmosphere and ocean currents

How it Works... Tropical Wet Climate Latitude – in the tropics HOT Altitude – low land doesn’t stop air flow until mtns. in the west Nearness – flat land “acts coastal”, allows moisture inland Direction – air flow brings in warm, moist air from the ocean which then hits the mountain and rains

The Tropical Zone Figure 1 Biomes of the Tropical Zone                                           

Temperate and Polar Zones

Temperate and Polar Zones

Why are there different climates on the earth? Explain with details. Reading check Why are there different climates on the earth? Explain with details.

Student led closing The arrows in the cross section below show winds moving across northern New York State into Vermont during the summer. Compared to the climate of location A, the climate of location B is… Why? a. warmer and wetter c. cooler and drier b. cooler and wetter d. warmer and drier The map shows an imaginary continent on Earth. Arrows represent wind direction. Letters A through D represent locations on the continent. Locations A and B are at the same latitude and at the same elevation at the base of the mountains. The climate at location C is much drier than at location D. This difference is best explained by the fact that location C is located…. a. at a latitude that experiences longer average annual daylight b. at a latitude where air is sinking and surface winds diverge c. farther from any mountain range d. closer to a large body of water ANSWER:  B