1. WEATHER AND CLIMATE

2. Where Weather Occurs Atmosphere (lowest layer of air that surrounds Earth) Troposphere: where most weather occurs (lowest layer) Stratosphere: few clouds form there

3. Weather Instruments Thermometer: measures air temperature Barometer: measures air pressure Rain Gauge: measures the amount of precipitation Wind Vane: shows direction of wind

4. Air Pressure (weight of air) Low pressure = warm air (warm) Humidity High pressure = cool air (cold)

5. Water in the Air Humidity- amount of water in the air How does it get there???? Oceans are the BIGGEST source of water - As sun heats the oceans, the water turns into water vapor, which rises into the air Evaporation: process of liquid changing into vapor Condensation: water vapor turning back into liquid drops of water (forming clouds)

6. Types of Clouds Cumulonimbus: tall and bring thunderstorms and sometimes hail Cirrus: high clouds mostly made of ice crystals (Fair weather) Cumulus: form when large bubbles of warm air rise rapidly (piled and puffy- fair weather but can produce light rain) Stratus: form layers (fog) and produce rain or snow

7. Questions 1.) How do weather scientists observe and measure weather conditions? 2.) How is water recycled in the water cycle? 3.) What causes clouds to form? 4.) It is a grey, cloudy day and light rain is falling. What type of cloud would you expect to see? Explain.