1 / 48

MET 112 Global Climate Change -

MET 112 Global Climate Change -. CLOUDS and CLIMATE. Prof. Menglin Susan Jin Department of Meteorology, San Jos State University. Outline Clouds Formation Clouds Climatology. Clouds and the Radiation Budget. Clouds by Christina Rossetti

ghalib
Download Presentation

MET 112 Global Climate Change -

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MET 112 Global Climate Change - CLOUDS and CLIMATE Prof. Menglin Susan Jin Department of Meteorology, San Jos State University Outline Clouds Formation Clouds Climatology Clouds and the Radiation Budget

  2. Clouds by Christina Rossetti White sheep, white sheep,On a blue hill,When the wind stopsYou all stand stillWhen the wind blowsYou walk away slow.White sheep, white sheep,Where do you go?

  3. A Scientists’ view of Clouds Clouds are formed when air containing water vapor is cooled below a critical temperature called the dew point and the resulting moisture condenses into droplets on microscopic dust particles (condensation nuclei) in the atmosphere. CLOUDS: A visible mass of liquid water droplets suspended in the atmosphere above Earth's surface. http://earthobservatory.nasa.gov/Library/glossary.php3

  4. A good repository of cloud photos in various categories can be found at www.cloudappreciationsociety.org/gallery

  5. Video: cloud formation in Tucson • http://www.youtube.com/watch?v=NiCSk1zxMEs Timelapse of Tucson cloud formations MET 112 Global Climate Change

  6. Questions • What role do clouds play on the Earth’s climate? • What would happen to our climate if clouds were to increase/decrease? • How does clouds formation change with pollution?

  7. Video • http://www.met.sjsu.edu/metr112-videos/MET%20112%20Video%20Library-MP4/clouds/ DTS-5.mp4 Clouds-1.mp4 –clouds and aerosols MET 112 Global Climate Change

  8. Clouds Roles - Importance of Clouds • Clouds is part of hydrological cycle to move water • Clouds is key in energy • Clouds absorb/reflect short wave radiation (clouds alebedo effect) • Clouds emit longwave radiation back to space • clouds absorb surface longwave radiation and keep the heat in the atmosphere to warm the surface (clouds greenhouse effect) MET 112 Global Climate Change

  9. Earth System Water Cycle

  10. 100% of the incoming energy from the sun is balanced by 100% percent total energy outgoing from the earth. incoming energy from the Sun = outgoing energy from the Earth.

  11. since the Earth is much cooler than the Sun, its radiating energy is much weaker (long wavelength) infrared energy. energy radiation into the atmosphere as heat, rising from a hot road, creating shimmers on hot sunny days. The earth-atmosphere energy balance is achieved as the energy received from the Sun balances the energy lost by the Earth back into space. So, the Earth maintains a stable average temperature and therefore a stable climate. http://www.srh.noaa.gov/jetstream//atmos/energy.htm MET 112 Global Climate Change

  12. Clouds Formation Clouds are formed when air containing water vapor is cooled below a critical temperature called the dew point and the resulting moisture condenses into droplets on microscopic dust particles (condensation nuclei) in the atmosphere. CLOUDS: A visible mass of liquid water droplets suspended in the atmosphere above Earth's surface. http://earthobservatory.nasa.gov/Library/glossary.php3

  13. Water freely evaporating and condensing Since more water molecules are evaporating than condensing, then net evaporation is occurring. MET 112 Global Climate Change

  14. Clouds can form along warm and cold fronts, where air flows up the side of the mountain and cools as it rises higher into the atmosphere, and when warm air blows over a colder surface, such as a cool body of water.

  15. Water in the atmosphere • Definitions: • Evaporation: • Condensation: • Precipitation: Process where a liquid changes into a gas Process where a gas changes into a liquid Any liquid or solid water that falls from the atmosphere to the ground. (i.e. RAIN!)

  16. Condensation • The process by which water vapor changes to a cloud droplet • Water vapor molecules may ‘stick’ to condensation nuclei and grow (billions) to eventually form cloud droplet. • Examples of condensation nuclei include: • Dust • Salt • Smoke • Condensation occurs primarily as temperature cools: • colder the molecules more likely they are to ‘stick’ to • other molecules

  17. CCN Aerosols Affect Cloud Droplet Size 1.Aerosols serve as cloud condensation nuclie (CCN) Ocean case Land case CCN 2. More aerosols,they will compete for water vapor to condense on, so smaller cloud droplet MET 112 Global Climate Change

  18. Zonal Mean Cloud Effective Radius(M. D. King, S. Platnick et al. – NASA GSFC) Why ocean has larger cloud droplets than land? July 2006 (Collection 5) Aqua

  19. Clouds and radiation Cloud - Climate Interactions Albedo effect - COOLING • Clouds reflect incoming solar radiation. • The cloud droplet size and total water content determine the overall reflectivity. Greenhouse effect - WARMING • Clouds are good absorbers (and emitters) of long wave (infrared) radiation.

  20. Clouds and day to day temperatures Imagine that you are going camping in the Sierras with your friends. On the first day (and evening) it is clear, while on the second day (and evening) it is cloud. Based on this information alone: Which day would be warmer? Which evening would be warmer? Explain your answers.

  21. Which day would be warmer? • First day (clear) • Second day (cloudy) • Both the same

  22. Which evening would be warmer? • First day (clear) • Second day (cloudy) • Both the same

  23. Clouds types

  24. Low and High clouds Consider two types of clouds: • Low levels clouds • High levels clouds Q: How is the Earth’s surface energy budget different for low clouds compared to high clouds?

  25. Clouds and climate Cloud A: Low level, (dark, thick) Cloud B: High level, light (sub visible or thin) Excellent reflector of incoming radiation; good absorber/emitter of infrared radiation Fair/poor reflector of incoming radiation; good/excellent absorber/emitter of infrared radiation • So, clouds both warm and cool the earth. • Overall, though, clouds act to cool the earth

  26. Changes in clouds • Increases in low level clouds will: • Increases in high level clouds will:

  27. Changes in clouds • Increases in low level clouds will: • cool the surface (cooling outweighs warming) • Increases in high level clouds will: • warm the surface (warming outweighs cooling)

  28. Cirrus

  29. Altocumulus (possibly cirrocumulus, depending on altitude of the clouds)

  30. Stratocumulus

  31. Broken stratocumulus

  32. Nimbostratus

  33. Cumulus humilis (commonly called 'fair weather cumulus')

  34. Cumulus

  35. Cumulus

  36. Cumulus

  37. Cumulus

  38. Cumulonimbus

  39. Stratus

  40. Stratus

  41. Cirrus

  42. Clouds That Look Like Things

  43. Explain how the earth’s climate would change as a result of aircraft contrails.

  44. Class Participation Concept Map

  45. Activity : Water Concept Map Draw a concept map using the following terms. You may add additional terms if you wish. Water vapor Ice Liquid water Condensation Evaporation Gas High Cloud Low Cloud Precipitation Condensation nuclei Temperature Warming Cooling Air

More Related