The Atmosphere

1. The Atmosphere T-CAP Study Materials Shelby Webb

2. Uneven Heating of the Earth The Earth's major external source of energy is the Sun. The Earth is constantly receiving solar energy, but different areas of Earth receive different amounts of solar energy. This affects weather and climate. The solar energy received by the Earth causes ocean currents, winds, seasons, and climate differences.

3. Uneven Heating of the Earth,Ocean Currents The uneven heating of the Earth's surface creates energy flow. Winds and ocean currents flow from warmer areas to colder areas, which means that they travel from the equator toward the poles.

4. Uneven Heating of the Earth,Wind : Land and Sea Breezes In coastal areas during the day, the land heats up more than the ocean. This uneven heating causes wind to blow from the ocean to the land during the day, as the warm air over the land rises, and the cooler ocean air moves in to take its place. These winds are called sea breezes. Sea Breeze Land Breeze

5. Uneven Heating of the Earth,Seasons The Earth's seasons occur because of the tilt of the Earth's axis. When either the Northern Hemisphere or the Southern Hemisphere is tilted towards the Sun, it is receiving the most solar radiation and is experiencing summer. When it is tilted away from the Sun, it is receiving the least amount of radiation and is experiencing winter. **Please go to the next slide to see a picture that can help understand this current information**

7. Uneven Heating of the Earth,Climate Differences : Coastal vs. Inland Oceans also have a major effect on climate. Water absorbs solar energy without changing temperature much. This means that ocean temperature remains within a small range throughout the year, even when the amount of solar energy received is changing. This explains why the climate in coastal areas changes less with the seasons than areas that are far away from the coast.

8. There are three major types of water movement in the ocean. They are: 1. Currents – continuous, directed movements of ocean water that are produced by forces acting upon the water. Surface ocean currents are primarily formed by winds that cause the water to move in the direction that the wind is blowing. Deep ocean currents form due to Earth's gravity—different sections of ocean water sink and rise as currents due to differences in density. These density differences are caused by differences in salinity and temperature. 2. Tides – rising and falling of the water level caused by the gravitational forces of the moon and the sun 3. Waves - vertical movements of water, typically involving waves moving towards the shore and breaking in shallow water near the coastline.

9. Atmospheric Convection & Wind Atmospheric Convection The Sun is the ultimate driving force for weather and climate patterns on Earth. Due to Earth's shape, position, and movement through space, the Sun heats Earth's atmosphere unevenly. Only half of Earth receives sunlight at one time. In addition, solar rays are more concentrated at the equator than at areas of higher latitude. Thus, some parts of the atmosphere become warmer than other parts. When air heats up, it becomes less dense and rises. Colder, denser air sinks and moves in to take the place of the rising, warmer air. This constant circulation of air is driven by temperature differences, and is called convection.

10. Atmospheric Convection & Wind Wind Warm air has a lower pressure than cool air. Warm air molecules are spread out; therefore, they do not place a lot of pressure on the area beneath. Cool air molecules gathered close together place greater pressure on the area beneath. To maintain a balance, air masses flow from areas of high pressure to areas of low pressure. It is during this process that wind is produced. The uneven heating of the Earth is the cause of weather differences like low- and high-pressure zones, strong and light winds, temperature differences, stormy and fair weather, humid and dry conditions, and stable and unstable air conditions. Low pressure areas tend to have stormy weather and stronger winds. High pressure areas tend to have fair weather and light winds.

11. Predicting the Weather Weather refers to the condition of the air at a certain time. It is influenced by heat and water. As the sun heats our atmosphere, water evaporates and warm air rises. This rising air cools off and condenses to form clouds. When the clouds become too heavy, the moisture falls back to the earth. This precipitation can be in the form of rain, snow, sleet, or hail. Because certain types of weather react to each other in predictable ways, meteorologists are able to study weather conditions to make weather forecasts. Meteorologists commonly observe the movement of air masses, which interact with each other and cause changes in weather. A front is the zone where two air masses meet. A cold front occurs when a mass of cold air pushes under a mass of warm air. This causes moisture to condense, and usually brings rainfall.

12. Predicting the Weather Meteorologists do not rely solely on their observations and patterns of weather behavior. They also use computers, satellites, and a number of tools to predict weather. They rely on the information provided by thermometers, barometers, rain gauges, and anemometers, to name a few. The information gathered helps meteorologists predict not only changes in temperature, relative humidity, and wind patterns, but also more severe weather events such as thunderstorms, hurricanes, and conditions which are favorable for tornadoes or flooding.

13. Weather Tools Anemometer Thermometer Snow Gauge Wind Vane Barometer Rain Gauge

14. A thermometer is used to measure temperature in degrees Fahrenheit or Celsius. • A snow gauge is used to measure the amount of snow that falls in a given period of time. • An anemometer is used to measure wind speed in one area. • A wind vane is a tool used for measuring wind direction. • A rain gauge is a piece of equipment designed to measure the amount of rain that falls in a given period of time. • A barometer is used to measure air pressure.