Understanding Earth's Atmosphere and Climate Dynamics

1. 011 Global Warming

2. Vernal equinox March 21 Sun vertical at equator Northern Hemisphere Names Winter solstice Dec. 22 Sun vertical at 23.5oS Winter solstice Dec. 22 Sun vertical at 23.5oS Summer solstice June 21 Sun vertical at 23.5oN Autumnal equinox Sep. 23 Sun vertical at equator

3. Earth further from sun Earth closer to sun

4. The radiant energy emitted by the sun. It is highest at the equator and lowest at the poles. Solar irradiance- We are interested in conditions near the Earth’s surface What are some factors that effect exposure to irradiance?

5. Non-rotating Earth Convection cell model

6. Add rotation and add landmasses unequal heating and cooling of the Earth

7. Physical properties of the atmosphere: Density • Warm, low density air rises • Cool, high density air sinks • Creates circular- moving loop of air (convection cell)

8. Physical properties of the atmosphere: Water vapor • Cool air cannot hold much water vapor, so is typically dry • Warm air can hold more water vapor, so is typically moist • Water vapor decreases the density of air

9. Physical properties of the atmosphere: Pressure • A column of cool, dense air causes high pressure at the surface, which will lead to sinking air • A column of warm, less dense air causes low pressure at the surface, which will lead to rising air

10. 90o High pressure, dry climate 60o Low pressure, wet climate High pressure, dry climate 30o ITCZ intertropical convergence zone= doldrums Low pressure, wet climate 0o 30o 60o 90o

11. Idealized winds generated by pressure gradient and Coriolis Force.  • Actual wind patterns owing to land mass distribution..

12. The Coriolis effect • The Coriolis effect • Is a result of Earth’s rotation • Causes moving objects to follow curved paths: • In Northern Hemisphere, curvature is to right • In Southern Hemisphere, curvature is to left • Changes with latitude: • No Coriolis effect at Equator • Maximum Coriolis effect at poles

13. The Coriolis effect on Earth • As Earth rotates, different latitudes travel at different speeds • The change in speed with latitude causes the Coriolis effect

14. North Pole Buffalo moves 783 mph Quito moves 1036 mph Buffalo 15o N equator Quito Buffalo equator 79oW Quito South Pole

15. Current Gyres • Gyres are large circular-moving loops of water • subtropical gyres • Five main gyres (one in each ocean basin): • North Pacific • South Pacific • North Atlantic • South Atlantic • Indian • Generally 4 currents in each gyre • Centered about 30o north or south latitude

16. Geostrophic flow and western intensification • Geostrophic flow causes a hill to form in subtropical gyres • The center of the gyre is shifted to the west because of Earth’s rotation • Western boundary currents are intensified Figure 7-7

17. Wind-driven surface currents

18. Global Warming

19. The E-M Spectrum

20. Fate of Solar Radiation Reaching the Earth reflection clouds snow and ice the earth’s surface atmospheric dust

21. Fate of Solar Radiation Reaching the Earth absorption atmosphere oceans land plant photosynthesis

22. Fate of Solar Radiation Reaching the Earth radiation

23. The Greenhouse Effect

24. Greenhouse Gases Carbon Dioxide Methane Nitrous Oxide Water Vapor Ozone

25. Atmospheric CO2 (ppm) Temperature Change (oF) Thousands of Years Before Present

26. Atmospheric CO2 & Surface Temperature Trends Atmospheric CO2 (ppm) Temperature Temperature Change (oF) Carbon Dioxide Year

27. Predicted changes with increased greenhouse warming • Sea level rise • Increased plant primary productivity • Shifts in the distribution of plants and animals • Water contamination and outbreaks of water-borne diseases • Increased storm severity • Potential melting or enlargement of polar ice caps • Changes to patterns of rainfall • More severe droughts or increased precipitation • changes to ocean circulation patterns

28. Ice Age 18,000 years ago

29. Sea Level Changes due to Ice Ages and Ice Cap Melting

30. Mean Sea Level Rise Changes in Mean Sea Level Year

31. Summer Arctic Sea Ice Decline Comparison between 1979 & 2005

32. Early Fall Arctic Sea Ice Extent Sea Ice Extent (million km2) Year

33. Greenland Seasonal Surface Melting Surface melting

35. Permafrost

36. Permafrost

37. Permafrost melting

38. Permafrost melting

39. Permafrost melting Drunken forest

40. North Atlantic Tropical Storms 10-year running average Named Tropical Storms Year

41. 1 Meter Sea Level Rise Waikiki http://www.soest.hawaii.edu/HMRG/FloodingOahu/index.php http://www.soest.hawaii.edu/coasts/sealevel/waikiki.html

42. Sea Level Rise • Destroys coastal habitat (e.g. salt marshes, mangroves) • Destroys human property • Increases pollution • Decreases freshwater supply

43. Effect on Marine Life • Phytoplankton bloom due to light and temperature cues • Changes will impact food web • Hypoxia may result

44. Effect on Fisheries • Migrations are in response to temperature • May impact fisheries

45. Effect on Corals • Coral bleaching • Leads to loss of habitat and food for reef- dependent species

46. Currents • Oceanic conveyor belt may change ocean currents • Currents carry plankton • Bring food and oxygen • Distribute eggs and larvae • Remove wastes and pollutants

47. Salinity • Animals have a narrow range of tolerance • Glacial melting inputs lots of freshwater

48. Acidity • CO2 makes water acidic • Corals and other calcium carbonate species can’t make skeleton • Impact on plankton development impacts food web

49. Temperature • Higher temperature results in less O2 • - Results in hypoxia • Ice melting leaves no resting/hunting areas for polar bears • Antarctic Krill impacts food web

50. Invasive Species • Algae smothers coral • Invasive species out-compete natives