1 HOLT World Factors Affecting Climate Geography Today

#1 HOLT World Factors Affecting Climate Geography Today Effect of the Sun on Earth’s atmosphere: n greenhouse effect -Atmosphere traps heat energy, keeps planet warm. • Global Warming is the when the atmosphere becomes more dense because of pollution. It make the world heat up. 1 HOLT, RINEHART AND WINSTON

• During the Earth’s revolution around the sun, the sun’s direct rays fall on the Earth in regular patterns. • Latitude has the greatest effect on a place’s climate.

Section 1 Factors Affecting Climate HOLT World Geography Today (Wind) Atmospheric pressure and energy distribution: n Low-pressure zones are caused by warm air, which expands and rises. n High-pressure zones are caused by cold air, which is dense and sinks. n Pressure differences cause air flow (wind) and energy distribution around the globe. n Warm air moves through the upper atmosphere until it cools and falls; cold air moves along Earth’s surface until it heats up and rises. 3 HOLT, RINEHART AND WINSTON

HOLT World Geography Today 4 HOLT, RINEHART AND WINSTON

HOLT World Geography Today 5 HOLT, RINEHART AND WINSTON

HOLT #3 Factors Affecting Climate World Geography Today Global winds affect weather and climate: n Pressure differences cause wind. n Winds move heat and cold across the Earth’s surface. n Prevailing winds blow from the same direction most of the time, causing similar weather. n A front occurs when two air masses of widely different temperatures or moisture levels meet. 6 HOLT, RINEHART AND WINSTON

HOLT World Geography Today 7 HOLT, RINEHART AND WINSTON

#4 Factors Affecting Climate HOLT World Geography Today Oceans affect weather and climate: n Water heats and cools more slowly than land, making coastal areas milder than inland areas. n Ocean currents move heat between the tropics and polar regions, helping to maintain Earth’s energy balance. 8 HOLT, RINEHART AND WINSTON

HOLT World Geography Today 9 HOLT, RINEHART AND WINSTON

#5 Weather Factors HOLT World Geography Today Effects of mountains and elevation on weather and climate: n Higher you go (elevation), colder it gets. n Mountains cause orographic effect: moist air meets a barrier and is pushed upward, causing cooling, condensation, and precipitation. n Mountainside facing wind is the windward, wetter side; side facing away from wind is the leeward, drier side, called the rain shadow. 10 HOLT, RINEHART AND WINSTON

• The temperature of a place depends on its elevation. • For every 1000 feet gained, the temperature drops an average of 3. 5 degrees. • For example, Quito is about 9, 000 feet above sea level. Even though it is on the equator, it is about 25 degrees cooler than lower areas. • The higher you get the colder it gets, the lower you get the hotter it gets.

HOLT World Geography Today 12 HOLT, RINEHART AND WINSTON

Middle Latitude Storms HOLT World Geography Today n Middle-latitude storms form when cold dry polar air mixes with moist warm tropical air. Examples include thunderstorms and tornadoes. 13 HOLT, RINEHART AND WINSTON

HOLT Tropical Storms World Geography Today n Tropical storms are usually smaller and lack fronts. Examples include hurricanes and typhoons. n Warm water strengthens a hurricane while cold water and land weaken hurricanes 14 HOLT, RINEHART AND WINSTON

HOLT World Geography Today 15 HOLT, RINEHART AND WINSTON