CLIMATE What is Climate? Climate - the weather conditions prevailing in an area in general over a long period Climate Zones Climate BrainPOP Tundra Rain Forest Desert Deciduous Forest Factors Affecting Climate Temperature Factors 1. Latitude • Average Yearly Temperature • Yearly Temperature Range 2. Altitude 3. Ocean Currents 4. Marine Vs. Continental Rainfall Factors 1. Latitude 2. Mountains - Orographic Precipitation Latitude - Average Yearly Temperature • The area that receives the • As latitude increases, average yearly most direct rays of the Sun temperatures decreases (equator, 0°) will have the highest yearly temperatures. Avg. • The area that receives the least direct rays of the sun (poles, 90°) will have the lowest yearly temperatures. Yearly Temp. 90 ° 0° Latitude Latitude - Yearly Temperature Range • Equatorial areas receive the direct rays of the Sun for most of the year. Therefore, the yearly temperature does not change much. Temperature Low Latitudes Mid Latitudes High Latitudes JFMAMJJASOND Month Latitude - Yearly Temperature Range Yearly Temperature Range • As latitude increases, yearly temperature range increases 90 ° 0° Latitude Altitude - Average Yearly Temperature Range • Altitude - the height of an object above sea level. Low average yearly temperature range High average yearly temperature range Altitude - Average Yearly Temperature Average Yearly Temperature • As altitude increases, average yearly temperature decreases Altitude Ocean Currents • Ocean currents move warm water from the equator towards the poles. • Ocean currents move cold water from the poles back to the equator to be heated again. (pg. _4_ of ESRT) Animation Ocean Currents Marine vs. Continental • Sea or land locations affects temperature ranges. Since land gains and loses heat much more quickly than water, land areas tend to have warmer summers and cooler winters. Coastal areas near the ocean have cooler summers and milder/warmer winters. • Coastal areas have marine climates with a small yearly temperature range and areas inland have continental climates with a larger yearly temperature range Marine Vs. Continental This graph shows the average monthly temperatures for two cities, A and B, which are both located at 41ºN latitude. Why is there a difference in the average yearly temperature range for the two cities? • Because City A is located inland (continental) and City B Interactive Climate Map is located near water (marine) Rainfall Factors - Latitude • Uneven heating of the Earth produces global wind & pressure belts. These belts determine the wetness or dryness of an area. • Low Pressure - rising air creates precipitation • High Pressure - sinking air creates a lack of precipitation Animation Latitude Continued What latitudes are areas of low pressure? 0°, 60°N, 60°S What is the climate like there? High rainfall What latitudes are areas of high pressure? 30°N, 30°S, 90°N, 90°S What is the climate like there? Low rainfall Orographic Precipitation WINDWARD Windward 4.Condenses 5. Precipitation 3. Cools rises 2. Expands 1. Rises Warm air Humid/Moist LEEWARD 6. Sinks 7. Compresses 8. Warms Arid/Dry Windward Vs. Leeward • Rainfall occurs on the windward side of the mountain where the air is rising. • Cool & Wet • It is dry on the leeward side of the mountain where the air is sinking. • Warm & Dry Orographic Precipitation Video El Nino • A warming of the surface water of the eastern and central Pacific Ocean, occurring every 4 to 12 years and causing unusual global weather patterns. • El Nino brings heavy rain to western South American and drought to eastern Australia and Indonesia. Animation El Nino Video Lake Effect Snow • The air moving over the water needs to be cooler than the water. • The surface of the lake can’t be frozen Lake Effect Snow • Water begins evaporating off of the surface of the lake into the air. • Fetch - distance over open water • The greater distance the wind blows over the warm water, the greater the convection /evaporation. Lake Effect Snow CLOUD FORMATION CONDENSES COOL EXPAND RISE Warm air over water begins to Lake Effect Snow In some localities, wind blowing from a lake onshore is forced to climb up hills creating the orographic effect Lake Effect Snow Video Areas Affected by Lake Effect