9 25 15 9 28 15 Dr Frauenfeld Chapter 5 Global Temperature I Temperature Concepts and Measurements a Temperature Scales i Fahrenheit F 180 F separate melting freezing 32 F and boiling point 212 F ii Celsius C 100 C separate melting freezing 0 C and boiling point 100 C iii Kelvin K starts at absolute zero 1 C 1 K Temperature in K Celsius 273 II Principal Temperature Controls a Latitude and Temperature i Affects insolation more insolation higher temperature The closer to the equator the less variability in temperature the farther from the equator the greater variability in temperature EXCEPTION Edinburgh Scotland it is an island so greater maritime influence and the gulfstream b Altitude and Temperature i High altitude greater daily range but a lower annual average ii Temperature in the troposphere decreases at a constant rate of 6 4 C 1000m because the density of the atmosphere decreases as you increase altitude less ability to absorb and radiate sensible heat iii The higher the altitude the more intense the insolation is less atmosphere above you iv Lower average temperatures greater nighttime cooling larger day night range 9 25 15 9 28 15 Dr Frauenfeld c Cloud Cover and Temperature i Moderates temperature cooler days and warmer nights ii Cloud Albedo Forcing during the day 1 Stratus clouds have a 90 albedo iii Cloud Greenhouse Forcing during the night 1 Cirrus clouds have a 50 albedo iv Approximately 50 of the Earth is covered in clouds at any given time v Clouds normally moderate temperatures depending on cloud type could height and cloud amount In General Clouds 1 During night insulate raise nighttime minimum temperature have warming vi 2 During day reflect lower the daily maximum temperatures can have cooling effect effect d Land Water Differences and Temperature i Maritime vs Continental Evaporation cooling Transparency Specific Heat Movement Overall Land Less evaporation because lower latent heat warmer Opaque so energy is concentrated at the surface warmer Lower specific heat so it doesn t take a lot of energy to heat up an it loses heat quickly No mixing between layers so energy is concentrated at the surface warmer Warms and cools rapidly extreme temperatures Water Greater evaporation because higher latent heat cooler Transparent so energy is able to spread out through a larger volume cooler Higher specific heat so it takes a lot of energy to heat up and retains heat longer Great mobility and mixing i e ocean currents so energy is spread out cooler Cools and warms slowly moderate temperatures ii Conditions are much milder if you live near a body of water 1 Maritime influence means that mild conditions are advected horizontal movement to surrounds even if you don t live by the ocean a Summers near oceans aren t as warm as in the interior of the continent b Winters near oceans aren t as severe as in inland locations c Onset of seasons is delayed near the oceans d The range of temperatures is much less than the range of temperatures on the interior of the continent 9 25 15 9 28 15 Dr Frauenfeld iii Ocean Currents have a significant impact on temperature and atmospheric conditions 1 East coasts always have warm ocean currents a From equatorial areas b Bring mild conditions and greater evaporation c Example is the Gulf Stream 2 West coasts always have cold ocean currents a From polar areas b Bring cool conditions c Example is the California current III Air Temperature and the Human Body a Wind Chill Correlates temperature cold and wind speed i Greater wind speed makes the cool air feel cooler b Heat Index Correlates temperature heat and humidity i Greater humidity makes warm air feel warmer