Living in Our Ocean of Air Chapter 1-2 WX Elements

1. Living in Our Ocean of AirChapter 1-2 WX Elements

2. Source: http://www.geog.ucsb.edu/~joel/g110_w06/lecture_notes/sun_angle/agburt02_12.jpg

3. Angle of incoming radiation and hours of sunlight affect heating. • Source: http://easyweb.easynet.co.uk/~geography.net/kew/factors(1).htm

4. Wind will flow from high to low.

5. Hot air rises generating an area of low pressure. • Air cools as it rises and falls generating an area of high pressure.

6. In the northern hemisphere, low pressure rotates in a counterclockwise direction. • In the northern hemisphere, high pressure rotates in a clockwise direction. • Source: http://myweb.cwpost.liu.edu/vdivener/notes/High-Low%20map.gif

8. Wind Facts Air moves horizontally from an area of high pressure to an area of low pressure.

9. Wind Facts Wind speed is measured with an anemometer.

10. Wind Facts • is cooling caused by the wind. • Local winds blow over a short distance.

11. Wind Facts • sea breeze- air over the water is cooler and denser than air over land. The flow is from higher pressure to lower pressure.

12. Wind Facts • land breeze - at night air over land is cooler and denser. Air flows from higher pressure to lower pressure.

13. Wind Facts • Global winds blow steadily from specific directions over long distances. Why did Columbus land In the Caribbean Islands? Wind Graphic Display

14. Wind Facts Gaspard Gustave de Coriolis • The Coriolis Effect, curvature of the wind, is caused by Earth’s rotation.

15. Wind Facts • Jet streams are high-speed winds about 10 km above Earth’s surface. What’s happening right now? What does it mean for weather for the next little while?

16. Dust Storm

17. Links • GOES satellite image index • Weatherunderground.com

18. Types of Clouds

20. Low Clouds • Stratus • Sheet - like cloud. • No turbulence. • May be risen fog. • Light drizzle or snow. • Close to Earth’s surface. • Can hide danger.

21. Low Clouds • Stratocumulus • Rolls or global masses. • Bulbous protrusions. • Heavy rain and snow • Varying turbulence. • Masks higher severe cloud buildups.

22. Low Clouds • Cumulonimbus • Vertical growth group. • Top has anvil shape. • High winds, snow, hail, rain, lightning, and tornadoes. • Extreme turbulence.

23. Low Clouds • Nimbostratus • Shapeless, low-level, moderate precipitation. • Fog and precipitation found beneath. • Visibility restricted. • Calm to light winds.

24. Middle Clouds • Altostratus • Relatively thin. • Sun may be seen through veil. • Ice crystals and super-cooled water. • Light precipitation. • Poor surface visibility.

25. Middle Clouds • Altocumulus • Wavy solid clouds with rounded outline. • Light intermittent rain or snow. • Commonly followed by thunderstorms. • Poor visibility and moderate surface winds.

26. High Clouds • Cirrus • Thin feathery clouds. • No precipitation. • Sign of approaching bad weather.

27. High Clouds • Cirrostratus • Thin, resembles a sheet or veil. • No precipitation. • Nearly transparent. • Often sign of approaching bad weather.

28. High Clouds • Cirrocumulus • Thin clouds. • Indicates high-level instability. • Similar to cirrostratus but they have a slightly “bumpy” appearance.

29. Fracto and Lenticular • Fracto • Broken and/or ragged. • Cumulus fractos. • Lenticular • Lens-like shape. • Tells turbulence, visibility, precipitation.

30. Cumulus with Vertical Growth • Fair weather cumulus • A puffy, cottonball appearance. • Develops from thermal updrafts. • Flights below can be bumpy and choppy.

31. Cumulus with Vertical Growth • Vertical growth, or building cumulus • Produce strong rain and moderate to severe turbulence. • Very strong updrafts. • With further building and increase in intensity, it becomes a thunderstorm.

32. Fog Types • Radiation Fog • Formed at night when land surfaces radiate much of the heat absorbed from the Sun back into space. • The cool land surface cools the air near it to below the dew point and fog is formed.

33. Fog Types • High Inversion Fog • A low fog. • Formed by condensation of water vapor at or near the top of cool air, which is overlain by a warmer air layer.

34. Air Mass Type and Origination

35. Air Mass Type and Origination • Air masses are identified by letter symbols. • A polar air mass (P) is cold. • A tropical air mass (T) is hot. • A maritime air mass (m) forms over water and is humid. • A continental air mass (c) forms over land and is dry.

36. Air Mass Type and Origination • Aviators and meteorologists in the continental United States are chiefly concerned with air masses origination at two sources. • Masses that move southward from Polar Regions. • Masses that move northward from Tropical Regions.

37. Air Mass Type and Origination • Cold air masses • Continental polar (cP) • Maritime polar (mP) • Arctic (A) • The principle warm air mass is maritime tropic (mT)

38. Temperature Classification of Air Masses • Based upon its temperature in relation to the surface over which it passes. • A cold air mass (k) is cooler than the Earth’s surface over which it is moving. • A warm air mass (w) is warmer than the Earth’s surface over which it is moving.

39. Temperature Classification of Air Masses • Continental polar cold (cPk) - originates in the polar zone and moves south over a warm surface. • Maritime tropical warm (mTw) - originates over the Gulf of Mexico and moves toward the north over a cold surface.

40. Characteristics of Air Masses • As an air mass moves away from its source, its original characteristics are changed because of the surface it passes over. It may: • Become warmer or colder. • Absorb or lose moisture. • Be lifted up by mountains or subside into valleys. • Cold air masses move more rapidly than warm air masses.

41. Fronts • The boundaries between air masses are called frontal zones or fronts. • This boundary or front moves along the Earth’s surface as one air mass displaces another. • If a cold air mass replaces a warmer air mass, the boundary is called a cold front. • If a warm air mass replaces a cold air mass, the boundary is called a warm front.

42. Cold Front

43. Fronts • Cold Fronts • As warm air is forced upward, it cools, condenses into clouds, creating thunderstorms. • If movement is rapid, with an abundance of water vapor, violent weather takes place. • Squall lines develop ahead of the front.

44. Fronts • Cold Fronts • Along the cold front there will be a low-pressure cell where the weather is at its worst. • Almost any type of clouds can be found near the cell. • Poor visibility, low ceilings and rain in summer. • Freezing rain and snow in winter.

45. Warm Front

46. Fronts • Warm Fronts • Connected to a low-pressure cell, travels northeastward. • If cell did not move, the front would dissipate. • Front slips upward over cool air and forms a wedge. • Rises slowly which delays condensation.

47. Fronts • Warm Fronts • Front is announced by cirrus clouds. • As front approaches other clouds, skies darken. • Near the frontal boundary, clouds are low, gentle rain falls and visibility is poor. • Warm rain falling into cooler air causes fog.

48. Fronts • Warm Fronts • After front passes, there is a rise in temperatures, general clearing and change in wind direction. • In winter a warm front causes icing conditions at low altitudes. • In northern latitudes snow may also be produced.

49. Stationary Front

50. Fronts • Stationary Front • When air masses stop, a stationary front develops. • Weather can be bad for aviation along the front. • About every form of weather can be found.