© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 7.2What is the normal global distribution global distribution pattern of pattern of temperature? temperature? Part B

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? Earths surfaceHeated earths surface Insolation Radiation Long wave radiation Conduction Convection How is insolation related to the global distribution of temperature? How is energy transferred into the atmosphere? When the earths surface is heated up, it releases heat energy and warms the air above through three ways.

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? When is the insolation the highest? When does the ground receive no insolation? What is the relationship between insolation and air temperature? The more the insolation, the ( higher / lower ) the air temperature. Air temperature is controlled by __________. insolation At noon. Between sunset and sunrise. Maximum insolation No insolation

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? Around 16-17°C Around 27-28°C What is the world distribution pattern of temperatures? What is the July temperature of London and Hong Kong? What is the January temperature of London and Hong Kong? Around 3°C 20°C ( Hong Kong / London ) has a higher temperature in both July and January.

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? What is the world distribution pattern of temperatures? ( Low- / Mid- ) latitude region What regions are London and Hong Kong located at? What conclusion can you draw from this? Temperature ( decreases / increases ) with increasing latitude. Temperature is ( lower / higher ) in lower-latitude regions. 1Air temperature is higher in low-latitude regions

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 2Temperature variation over latitude is more marked in winter in the Northern Hemisphere The ( Northern / Southern ) Hemisphere has a closely- spaced pattern of isotherms in January. It means temperature variation over latitude is more marked in winter in the Northern Hemisphere.

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 2Temperature variation over latitude is more marked in winter in the Northern Hemisphere January July Moscow: ____°C Jerusalem: ____°C Difference: ____°C Moscow: ____°C Jerusalem: ____°C Difference: ____°C Lets look at the temperatures of Moscow and Jerusalem. The two cities have a larger temperature difference in ( summer / winter ).

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? July What are the temperatures of Places A and B which are at the same latitude? Place A: ____°C Place B: ____°C Difference: ____°C January Place A: ____°C Place B: ____°C Difference: ____°C Places at the same latitude may have different air temperatures What conclusion can you draw from this?

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? January 3Places at the same latitude may have different air temperatures July The isotherms in mid-latitudes in the Southern Hemisphere are roughly parallel to the latitudes. Why? It is because most of the area there is covered by sea. The changes in temperature are relatively ( small / large ).

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 4There is a seasonal pattern of air temperature 0 July Compare the difference of temperatures of Tokyo and Sydney in July and January respectively. Temperature in July (°C) Tokyo Sydney Temperature in January (°C) January 0°0° 8 21 In July, it is ( summer / winter ) in the Northern Hemisphere and ( summer / winter ) in the Southern Hemisphere. In January, it is winter in the Northern Hemisphere and summer in the Southern Hemisphere

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? How is insolation related to the global distribution of temperature? What are the factors affecting temperature patterns? Factors affecting temperature patterns InsolationLand and sea WindsOcean currents AspectAltitudeCloud cover

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible?

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible?

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? How is insolation related to the global distribution of temperature? What are the factors affecting temperature patterns? Land and sea WindsOcean currents AspectAltitudeCloud cover Factors affecting temperature patterns Insolation The more the insolation received, the ( lower / higher ) the air temperature.

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 2Land and sea July January Moscow: 15°C Place A (over the sea): 8°C Place A (over the sea): -6°C Moscow: -15°C A A Why are there different temperatures at places at the same latitude? In July, Moscow is ( colder / hotter ) than Place A. In January, Moscow is ( colder / hotter ) than Place A.

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 2Land and sea 8°C Land absorbs heat more quickly 15°C Sea loses heat more slowly -6°C Land loses heat more quickly -15°C Heat can be transferred quickly through the land by __________. Hence, the land absorbs and loses heat quickly. The water in oceans is heated by __________. As oceans are large bodies of water, it takes time to transfer the heat. Hence, oceans absorb and lose heat slowly. conduction convection Sea absorbs heat more slowly Place A

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 2Land and sea Annual range of temperature Copenhagen: 18°C Moscow: 30°C ( Copenhagen / Moscow ) has a smaller annual range of temperature. Copenhagen is located at the coast. _______ help regulate the temperature along coastal areas. Oceans Maritime climate: Mild winters and cool summers Continental climate: Cold winters and hot / warm summers

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 2Land and sea Annual range of temperature What characteristics do you notice about the distribution of annual range of temperature? Annual range of temperature ( decreases / increases ) as the latitude increases; ( decreases / increases ) with the distance from the sea.

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? How do winds affect the temperature of a place? 3Winds This is the seasonal pattern of winds in Hong Kong: Hong Kong Winter Hong Kong Cold northerly winds blowing from the cold inland areas of the mainland Some places receive onshore winds in winter. The warm onshore winds from the sea help raise the winter temperature there. South-easterly winds blowing from the Pacific Ocean Summer Temperature in Hong Kong ( / )

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 4Ocean currents Ocean currents are seawater flowing along fixed routes. They are divided into warm currents and cold currents. Warm currents flow from equatorial areas to polar areas Cold currents flow from polar areas to equatorial areas

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 4Ocean currents How do ocean currents affect the temperatures of the places lying along their paths? Warm ocean currents originate from areas where the water is warm. The air above the currents becomes ( cold / warm ). Places lying along the paths of warm ocean currents have ( lower / higher ) temperatures.

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 4Ocean currents Cold ocean currents originate from areas where the water is cold. The air above the currents becomes cold. Places lying along the paths of cold ocean currents have lower temperatures.

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 4Ocean currents Glasgow Nain Located at similar latitudes, both Glasgow and Nain are affected by ocean currents. What do you notice about the relationship between the type of ocean current and mean temperatures in July and January of Glasgow and Nain? Ocean current Mean temperature in July Mean temperature in January Glasgow Nain North Atlantic Drift ( cold / warm ) current Labrador Current ( cold / warm ) current 17°C ( lower / higher ) temperature 8.2°C ( lower / higher ) temperature 5°C ( lower / higher ) temperature -21.7°C ( lower / higher ) temperature

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 5Aspect Aspect refers to the direction a slope faces in relation to the sun. Suns rays strike at a larger angle on south- facing slopes Suns rays strike at a smaller angle on north-facing slopes South-facing slopes receive ( less / more ) insolation per unit area North-facing slopes receive less insolation per unit area Northern Hemisphere What is the situation in the Southern Hemisphere?

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 6Altitude Denser air Heat loss _____________, ______ and _______________ in the atmosphere absorb long wave radiation and keep the air warm Water vapourdust carbon dioxide Less dense air Heat released from the earths surface is stored in the air Heat loss Less dense air absorbs ( less / more ) heat Air becomes less dense with increasing altitude. Heat loss is faster and thus the air temperature ( falls / rises ). The average rate of decrease in air temperature with height is 6°C per 1,000 metres. This is known as the ________________________. environmental lapse rate

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 7Cloud cover Earths surface Earths surface With cloud coverWithout cloud cover Insolation Direct reflection Place APlace B Daytime A large part of the insolation reaches the earths surface Only part of the insolation reaches the earths surface Which area would have a lower temperature? Insolation

© Oxford University Press 2009 Quit Part 7 Global warmingAre humans responsible? 7Cloud cover Night time Which area has a larger daily range of temperature? Earths surface Earths surface With cloud coverWithout cloud cover The warmth is kept The warmth is lost Only a small part of the radiation is released back to space A large part of the radiation is blocked by the clouds A large part of the radiation would be released back to space Place APlace B Longwave radiation Some radiation is absorbed by clouds