Weather Fronts and Ocean Circulation PDF

Weather fronts and Ocean circulation Oceanic Circulation Ocean Currents A persistent, dominantly horizontal flow of water controlled by wind patterns Gyres: large circular ocean movements What relationship do you notice with the northern hem...

Weather fronts and Ocean circulation Oceanic Circulation Ocean Currents A persistent, dominantly horizontal flow of water controlled by wind patterns Gyres: large circular ocean movements What relationship do you notice with the northern hemisphere ocean. current and the pressure type typically located at 30o N? Oceanic Circulation Circulation and Energy Transfer Energy surplus at the equator Energy deficit at the poles In order to maintain the Earth’s energy balance, absorbed solar energy is moved from regions of excess to regions of deficit, carried by ocean currents and atmospheric circulation (which we’ve talked about a bunch) © John Wiley & Sons, Inc.  Oceanic Circulation Ocean Currents Ocean circulation and energy transport: Warm surface waters in the tropics move poleward. Thermohaline circulation: Cold and dense waters in the N. Atlantic sink, flow equatorward, and eventually upwell to the surface at far distant locations to cool surrounding regions and © NG Maps complete the circuit. Visualizing Physical Geography Copyright © 2012 John Wiley & Sons, Inc. © NG Maps Air Masses Weather systems are patterns of atmospheric circulation that lead to distinctive weather events, such as cyclones or thunderstorms. © NG Image Collection © GOES/NASA  Weather refers to the state of the atmosphere at one location and at one time. It refers to short term changes in the atmosphere (Climate refers to Long term changes in the atmosphere): Air Masses Weather Air mass = an variables include: extensive Weather body of air in Temperature conditions which Moisture change from temperature What effects (dew point and RH) day to day and moisture air masses? Precipitation or even from characteristics Winds hour to hour. are fairly uniform over a large area.  Air Masses Movement of Air Masses Air mass modification When an air mass moves to a new area, its properties change due to the influence of the new surface environment. © U.S. Department of Commerce What air mass is impacting your region today?. Air Masses © U.S. Department of Commerce  Front = the surface or boundary of contact between two different air masses associated with a midlatitude cyclone (MLC). Fronts Four types of fronts: Cold Warm Stationary Occluded Fronts Cold Front A cold front is a moving weather front along which a cold air mass moves underneath a warm air mass, causing the warm air mass to lift rapidly. Cold fronts tend to move swiftly. © John Wiley & Sons, Inc. Air rises steeply. Cumulonimbus clouds and thunderstorms may form.  Fronts Warm Front A warm front is a moving weather front along which a warm air mass slides over a cold air mass, producing stratiform clouds and Which type of clouds first precipitation. Air rises gradually. indicates an approaching Air moves slower relative to cold warm front? fronts a. nimbostratus Nimbostratus clouds may form. b. stratus © John Wiley & Sons, Inc. c. altostratus d. cirrus Fronts Occluded Front A weather front along which a fast-moving cold front overtakes a warm front, forcing the warm air mass aloft Triangles and semicircles pointing in the same direction Stationary Front Little to no relative motion Blue triangles and red semicircles pointing in opposite directions Oceanic Circulation Cycles in Atmospheric and Oceanic Circulation El Niño–Southern Oscillation (ENSO) La Niña © NG Maps © NG Maps Oceanic Circulation Cycles in Atmospheric and Oceanic Circulation Climate effects of El Niño events © John Wiley & Sons, Inc. Vi sualizing Physical Geography Copyri ght © 2012 John Wiley & Sons, Inc.  Oceanic Circulation Cycles in Atmospheric and Oceanic Circulation North Atlantic Oscillation (NAO) Pacific Decadal Oscillation (PDO) © NG Maps © NG Maps