The pattern of weather that occurs in an area over many years. Determines the kinds of plants & animals that can live in an area and influences how people live. It’s the average of the area’s temperatures, precipitation, air pressure, humidity & the number of days of sunshine in the area.
What factors affect climate? 1. Latitude – the measure North & South from the equator, affected by direct sunlight 1.Polar Zones – solar radiation hits at a lower angle, heat is spread out more, it’s never warm here 2.Tropical Zones – (the tropics) warmest areas due to the direct solar radiation 3.Temperate Zones – more moderate temps, most of the United States is in this zone
What factors affect climate? 2. Landforms Along similar latitudes, mountains are colder than other locations at sea level due to the higher elevation. There are fewer molecules available to absorb the heat at the higher altitudes and the atmosphere is thinner.
What factors affect climate? 3. Locations of lakes and oceans Large bodies of water can affect coastal areas by absorbing or giving off heat, making these areas warmer in the winter & cooler in the summer than inland areas at similar latitudes
What factors affect climate? 4. Ocean currents Currents are warmer near the equator. When they flow past higher latitudes, they warm the land that they pass. When they cool off and flow back towards the equator, they cool the air & climates of nearby land
How do cities affect climate? In large cities streets, buildings, and parking lots heat up. Air pollution traps this heat. Temperatures can be 5 degrees higher in the city than in rural areas.
Why do we have different seasons? Because the Earth is tilted at an angle. As it revolves around the Sun, areas receive more direct solar energy at different times of the year.
Why are there changes in the climate now? The Greenhouse Effect The natural heating due to gases in the atmosphere trapping heat Common Greenhouse gases = water vapor, carbon dioxide & methane make life possible on Earth, but if they warm up too much, it’s a problem. It creates…
Global Warming The average global temperature of Earth is rising Results of global warming: melting glaciers would cause sea levels to rise which would increase flooding in coastal areas What causes global warming?
Choices PEOPLE make! 1.Burning fossil fuels – natural gas, coal & oil used for energy. All of these contain carbon which combines with oxygen to form carbon dioxide. This has caused a 25% increase in CO2 in the last 150 years! 2.Deforestation – destroying & cutting down trees increases CO2 levels because the trees are no taking in CO2 for the natural process of making wood & leaves
How do we reduce CO2 levels? Conserve electricity (means less fossil fuels are burned) Plant vegetation to help remove CO2 from the atmosphere naturally
What Causes Wind? As the sun warms the Earth's surface, the atmosphere warms too. Some parts of the Earth receive direct rays from the sun all year and are always warm. Other places receive indirect rays, so the climate is colder. Warm air, which weighs less than cold air, rises. Then cool air moves in and replaces the rising warm air. This movement of air is what makes the wind blow.
General Wind Formation Steps: The sun’s rays warm the earth. Earth radiates heat and warms the surrounding air. Cold air is warmed and becomes less dense. Less dense air will rise. As air rises it expands and cools. Cool air which is denser sinks and causes an increase in air pressure. Wind is formed.
Atmospheric Conditions That Cause Thunderstorms The sun heats the surface of the earth, which warms the air above it. If this warm surface air is forced to rise, it will continue to rise as long as it weighs less and stays warmer than the air around it. As the air rises, it transfers heat to the upper levels of the atmosphere. The water vapor begins to cool, releases the heat, condenses and forms a cloud. The cloud eventually grows upward into areas where the temperature is below freezing.
Atmospheric Conditions That Cause Hurricanes Warm, moist air Warm water for evaporation to occur from
Considering what you now know causes hurricanes and thunderstorms, what season(s) are they most likely to occur in? Why?