© 2011 Pearson Education, Inc. CHAPTER 6 Air-Sea Interaction

© 2011 Pearson Education, Inc. Physical Properties of the Atmosphere Mostly nitrogen (N 2 ) and Oxygen (O 2 ) Other gases significant for heat trapping properties

© 2011 Pearson Education, Inc. Movement of the Atmosphere Air always flows from high to low pressure.

© 2011 Pearson Education, Inc. Winds Northern Hemisphere –Clockwise High Pressure –Counterclockwise Low Pressure Southern Hemisphere - Opposite

© 2011 Pearson Education, Inc. Convection Due to density differences Warm air rises –Less dense Cool air sinks –More dense

© 2011 Pearson Education, Inc. Distribution of Solar Energy Concentrated at low latitudes Diffuse at high latitudes

© 2011 Pearson Education, Inc. Heat Gained and Lost

© 2011 Pearson Education, Inc. The Coriolis Effect Due to Earth’s rotation Deflects path –To right in Northern Hemisphere –To left in Southern Hemisphere Zero at equator Greatest at poles

© 2011 Pearson Education, Inc. If Earth didn’t rotate??? Simple

© 2011 Pearson Education, Inc. Three-Cell Model of Atmospheric Circulation

© 2011 Pearson Education, Inc. Global Atmospheric Circulation High pressures– DRY Cool falling –30 degree belts –Poles Low pressure zones – MOIST warm rising -Equatorial -60 degrees belts

© 2011 Pearson Education, Inc. Global Atmospheric Circulation Wind Belt and Circulation Cells Tradewinds Hadley Cell: 0–30 degrees: –Northeast in NH –Southeast in SH Westerlies Ferrel Cell: 30–60 degrees Easterlies Polar Cell: 60–90 degrees

© 2011 Pearson Education, Inc. Three-Cell Model of Atmospheric Circulation

© 2011 Pearson Education, Inc. Weather vs. Climate Weather – localized conditions, short term Climate – regional long-term average of weather Ocean Climate Zones Tropical Temperate Polar Weather Fronts……

© 2011 Pearson Education, Inc. Fronts Fronts – boundaries between air masses –Warm front –Cold front Storms typically develop at fronts.

© 2011 Pearson Education, Inc. Tropical Cyclones (Hurricanes) Large rotating masses of low pressure Need warm water (>77 degrees) Energy from latent heat of condensation Classified by maximum sustained wind speed Typhoons (West Pacific), Hurricanes (East Pacific, Atlantic)

© 2011 Pearson Education, Inc. Hurricane Intensity

© 2011 Pearson Education, Inc. Historical Storm Tracks

© 2011 Pearson Education, Inc. Hurricane Anatomy and Movement

© 2011 Pearson Education, Inc. Hurricane Destruction High winds Intense rainfall Storm surge – increase in shoreline sea level

© 2011 Pearson Education, Inc. Storm Destruction Historically destructive storms –Andrew, 1992 –Katrina, 2005 –Ike, 2008 –Sandy 2012

© 2011 Pearson Education, Inc. Three-Cell Model of Atmospheric Circulation

© 2011 Pearson Education, Inc. Subtropical Gyres Large, circular loops of moving water Edges has Boundary Currents Centered around 30 degrees latitude

© 2011 Pearson Education, Inc. Subtropical Gyres and Currents