Understanding Weather Patterns and Climate Factors

1. Chapter 3 The Changing Weather

2. Chapter 3 Terms • Condensation • Orographic Condensation • Convectional Condensation • Frontal Condensation • High Pressure System • Low Pressure System • Climate • Precipitation • Weather • Air Masses • Continental Artic • Maritime Tropical • Maritime Polar • Front • Ocean Currents • Gulf Stream • Labrador Current • Weather Radar Stations • Meteorologists • Radiosonde

3. Conditions leading to Condensation

4. Snow Snow forms when water vapour condenses at a temperature below the freezing point Read pp. 33 - 36

5. Snow Storm For a snowstorm to happen – it needs two things… Snow Wind

6. Low & High Pressure Systems Low Pressure System – Air rising over a warm surface High Pressure System – Cool air sinks towards the surface, pushing the air underneath away

7. Why we get wind… • Air over the North and South Poles sink, because it is cold, producing an area of high pressure • Air over the equator rises because it is hot, producing an area of low pressure • The earth rotates on its axis once every day, so that a point on the equator travels approximately 40000 km in 24 hours – a velocity of nearly 1700km/hr • Winds in the northern hemisphere blow counterclockwise into a low pressure area and clockwise out of a high pressure area • An area between high and low pressure feels the effects of both circulations • High winds can develop when areas of very high and very low pressure come close together Questions… Page 37 #’s 1 - 4

8. Factors which affect Climate • Climate – average conditions of temperature • Precipitation – rain, snow, humidity, pressure and wind • Weather – conditions of the atmosphere over a short period of time They can all be demonstrated on a climate graph…

9. Climate Graph Consists of… Temperature – on left of graph – shown by a line graph Precipitation – on right of graph – shown by a bar graph Months of the year – on bottom of graph Climate Graph Assignment

10. Factors which influence the climate in Atlantic Canada • Latitude – because of the shape of the earth’s surface, there are parts of Atlantic Canada which receive more intense sunshine than others • Air Masses – affect the climate because they take on the temperature and humidity characteristics of the areas in which they originate • Ocean Currents – the waters of the world’s oceans are constantly in motion. Tides move the water up and down while currents move water from place to place. The major ocean currents have considerable influence on climate. • Proximity to Water – Areas very close to large bodies of water stay cooler in summer and warmer in winter than areas inland • Elevation – As height increases, temperatures decrease, largely because air is so much thinner at high altitudes Read pp. 37 – 41 Questions…Page 42

11. Examining Weather Land & Sea – weather observers note and transmit information about the state of the atmosphere From the Air – use radar to detect, locate and measure the amount of precipitation in clouds From Space – weather satellites are used to make long-term weather forecasts Weather Radar Station Read pp. 43 – 45, Questions…Page 46 Read pp. 46 – 47, Questions…Page 48