Climates  UNIT 9  STANDARDS: NCES 2.5.1, 2.5.2, 2.6.1, 2.6.2,  LESSON 3

Lesson Objectives  In this lesson, you will learn about: What causes different climates How climates are classified How climates change as a result of natural events and human activities

What is a Climate?  Climatology  Climate  The study of Earth’s climates and the factors that affect past, present, and future changes.  Long Term weather patterns of an area.  Described in terms of temperature, precipitation, wind, and other weather variables.

What is NORMAL about a climate  Normals  Data that has been collected and analyzed for at least 30 years can be used to determine normals for a location. Generally at an airport.  Normals are not to be used to determine a weather change, but instead offer the average values over a long period of time.  Finally remember that normals only apply to a specific region. They normals for Raleigh, North Carolina cannot be used as normals for Anchorage, Alaska.

Climate Normals Lab  Normals offer a comprehensive look at local weather. Using the normal data collected for Jacksonville, Florida, complete the following:  1. According to the daily normals maximum temperatures, during what months would you expect the temperatures to be at least 90 o F?  2. What were the highest and lowest temperatures reported and in what months and year?  3. Graphing the lowest temperature and warmest temperatures in different colors, would you say Jacksonville, Florida is experiencing global warming?  Repeat for Raleigh, North Carolina (Extra Credit +5)

What causes climates?  Latitude  Latitude is the distance above or below the equator.  Different latitudes receive different amounts of solar radiation, because of the tilt and season.  23.5 o north or south of the equator is the tropics. Tropic of Cancer, Capricorn  The temperate zones lie between 23.5 o and 66.5 o. We live in the temperate zone.  Finally the polar zones are located from 66.5 o north or south. Polar regions are always cold.  Generally lower latitudes have warmer climates. Sunrays hit the latitudes of Earth at different angles at different times of the year, creating seasons. Low latitudes, those closest to the equator, get more direct sunlight. More direct sunlight creates more heat, so the low latitudes are the warmest latitudes.

Lines of Latitude

Latitudes and Climates

What causes climates?  Topography  Water heats up more and cools down more than land. So the proximity to large bodies of water affects the climate. Coastal regions are warmer in the winter.  Altitude greatly affects climate due to the temperature of the air in the different layers of the atmosphere.  Mountains are cooler than are plains. Rain is dropped on the windward side of a mountain as the water condenses and is often dry on the leeward side.

Windward and Leeward

What causes climates? Generally higher altitudes have colder climates. Mountains can also block wind and weather.

What causes climates?  Air Masses  Two main causes for weather are the movement and interaction of air masses. Air masses from different regions affect climate differently.  Consider the affect of polar air masses on the United States. This generally brings cooler weather and also precipitation.  Warm air, the Gulf Stream, generally brings warm moist air over the United States.  Both affect the climate of North Carolina.

Air Masses and Climate Generally, air warms up over land areas. Warm air rises, and cooler air comes in to take its place. This creates wind. The wind cycles drive weather and ocean currents.

Section Review  Compare and contrast temperature in the tropics, temperate zones, and polar zones.  How can climate weather be used by farmers?  How can climate normals often used incorrectly?  Describe two topographic features that affect climate.