Bell Ringer

1. Bell Ringer • What are nitrogen fixers, and why are they important? • __________ break dead organisms down into matter. This adds carbon and nitrogen back into the ecosystem. • Giant panda bears have a very low birth rate. Before they became a protected species, they were frequently poached, and lost much of their old habitats. Did they have a positive or negative growth rate?

2. Climate What determines our climate?

3. Climate • Climate refers to the average yearly conditions of temperature and precipitation. • Contrast with weather, the day-to-day conditions. • The biggest difference between climate and weather? • Weather changes frequently each day, but climate rarely changes from year to year.

4. Climate • Climate is determined by several factors. • How well heat is trapped by the atmosphere. • The latitude (north-south position) of each region. • The presence of wind and ocean currents. • The amount of precipitation present.

5. The Greenhouse Effect • Our atmosphere contains trace amounts of important greenhouse gases – gases that are capable of trapping heat energy. • Greenhouse gases include carbon dioxide, methane and water vapor. • Greenhouse gases trap heat energy, which keeps our atmosphere warm. • Without them, Earth would be 30 degrees Celsius cooler. That amounts to 86 degrees Fahrenheit! • However, too many greenhouse gases is not a good thing, either!

6. Latitude • Due to Earth’s shape and its tilted axis, the Earth does NOT receive sunlight evenly. • Sunlight is the primary means of heating up the atmosphere. Therefore, certain parts of Earth get a lot of direct sunlight, and are quite warm. • Other parts of Earth get little direct sunlight, and are quite cold.

7. Latitude • The polar zones are at the very top and bottom of Earth. • They get very little direct sunlight; the sun’s rays are at very low angles. • These regions are cold year-round.

8. Latitude • The tropical zone is located around the equator. • This region gets direct sunlight almost all year round. • As such, this region is quite warm year-round.

9. Latitude • The temperate zones are located in between the polar and tropical zones. • The angle of sunlight varies greatly during the year. • As such, climate changes from hot to cold, based on the seasons.

10. Wind and Ocean Currents • Throughout Earth, warm air and water rises, and cool air and water sinks. This principle is known as convection. • Convection causes air currents, better known as wind. • Convection also causes many ocean currents. Wind also produces ocean currents. • Currents transport heat all over Earth. Warm currents keep climate moderate, and cool currents make climate cold.

11. Precipitation • Areas close to large bodies of water are likely to see a lot of precipitation. • Why? • Mountain ranges create rain shadows. • Basically, clouds are forced upward due to the mountain range, which cools them down. This makes precipitation much more likely, and the cloud disappears. • As a result, the other side of the mountain is a lot less likely to get precipitation, creating a dry climate behind the mountain range.

12. Exit Ticket • What is the difference between climate and weather? • ___________ gases trap heat in the atmosphere, which keeps Earth warm. • The [polar, temperate, tropical] zone(s) have the largest range of possible climates. • The [polar, temperate, tropical] zone(s) receive little direct sunlight. • True or false: In convection, cool air rises, and warm air sinks.