Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Air-Sea Interaction (Chapter 8) The Solar Connection The Coriolis Effect The Winds Hurricane Wilma Observation Device: GOES-12 1 km visible imagery. Visualization Date: October 24, 2005 15:02:23 http://www.nnvl.noaa.gov/cgibin/index.cgi?page=items&ser=109929 Atmospheric Layers The ______________________ (air we breathe) is approximately: 78% _______________ 21% _______________ <1% _______________ <0.1% ______________________ 0.01% ______________________ Reasons for seasons… In addition to Earth’s orbit around the sun, there are ________ main reasons for _________ ________________ of Earth: 1 - The _____________ ___________ of Earth 2 - The ____________ ________________ of rotation 3 - Seasonal changes in ______________ from the sun to Earth As the Earth revolves around the sun, the north pole will tilt toward the sun for part of the year (summer), and away from the sun for part of the year (winter). When the _____________ hemisphere has summer, the ______________ hemisphere has winter As the Earth revolves around the sun, the _____________ at which we receive sunlight changes. In ___________, we receive __________ angle sunlight. Higher angle sunlight means _________ concentrated ________ and __________ summer weather. Notice how the lower angle sunligh spreads out, heating a larger area and therefore giving less concentrated heat. …so solar heating is uneven Uneven warming causes _________________ Convection occurs when warm air becomes ____ _______ and ______, then ______, dense air comes in to _______ the rising warm air = _____________________ Idealized Convection on Earth Warm air ______ at _________, ________ air flows from _______ to replace warm air at surface level. High, warmer air flows toward poles, then cools and sinks = circular pattern... Idealized Convection on Earth … but idealized convection is an oversimplification, why? Coriolis(1835) Effect… • The path of a moving object deflects to the ________ in the _______________ hemisphere and to the __________in the _____________ hemisphere. • … due the Earth’s rotation, wind flows east and west as well as north and south. http://www-history.mcs.standrews.ac.uk/history/PictDispl ay/Coriolis.html Relative motion The linear velocity of points on Earth’s surface decreases with increasing latitude. At the equator (0), the eastward speed is about 1,620 km/hr, but at the north pole (90N) the eastward speed is zero. This is key to understanding the Coriolis Effect on winds and ocean currents. Earth’s rotation and shape causes the Coriolis effect Real Life Example: This movie of a ball rolling across the surface of a rotating merry-go-round is a helpful demonstration of the Coriolis force. http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/crls.rxml •http://www.classzone.com/books/earth_science/terc/content/visualizations/es1904/es1904page01.cfm ?chapter_no=visualization Winds and the Coriolis effect _________________ plus ________________ effect gives us prevailing wind patterns. Air moves horizontally from areas of _______________ pressure to areas of ________ pressure = wind. Coriolis steers wind to the _________ in the ___________ hemisphere. General Circulation http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/global_winds.rxml Polar Easterlies: From 60-90 degrees latitude. Prevailing Westerlies: From 30-60 degrees latitude (aka Westerlies). Tropical Easterlies: From 0-30 degrees latitude (aka Trade Winds). The easterly trade winds of both hemispheres converge at an area near the equator called the "Intertropical Convergence Zone (ITCZ)", producing a narrow band of clouds and thunderstorms that encircle portions of the globe. How do hurricanes form? http://oceanexplorer.noaa.gov/edu/learning/player/lesson13.html Forcasting intensity… Tropical Cyclone Formation Tropical cyclones form in one air mass N Equator Core of tropical cyclone rotating counterclockwise Stepped Art Fig. 8-25, p. 220 Conditions Required for Tropical Depression Formation • Weather disturbance with __________ _________that draws in air from all directions (usually 5° - 20° latitude) • _______________ __________ _________ (0200m), ca. 80°F (27°C) or warmer Hurricane Development • ____________________: organized system of clouds and thunderstorms; wind speed LE _____ mph • _______________: cyclonic circulation develops; wind speed _________ mph; storm is named • _________________ (aka ___________ in the North Atlantic): intense cyclonic winds surrounding a well defined eye; wind speed GE _____ mph Saffir-Simpson Scale (NHC) • • • • • Category 1: 74-95 mph; minimal damage Category 2: 96-110 mph; moderate damage Category 3: 111-130 mph; extensive damage Category 4: 131-155 mph; extreme damage Category 5: GE 156 mph; catastrophic Common tropical cyclone tracks. The breeding grounds of tropical cyclones are shown as orange-shaded areas. The storms follow curving paths: first they move westward with the trade winds and usually away from the equator. Then they either die over land or lose power over the cooler ocean of mid-latitudes. Wilma Hurricane Andrew Hurricane Andrew 1992 Hurricane Mitch http://news.bbc.co.uk/2/hi/americas/202395.stm http://www.fortogden.com/fant-8.jpg Are hurricanes getting more intense due to warming seasurface temperatures? …probably Hurricane Impacts on Marine Life • Sea Conditions during Hurricane Isabel Storm Surge • Increased ________ __________ causes damage to marine and coastal ecosystems Coral Reef Storm damage and Resilience Slows growth and impacts framework, but allows for fragmentation and regeneration Cool water upwelling and mixing • Hurricane Isabel trail is evident from the wake of cool water Temp and Salinity Profile Changes during Hurricane Francis Fish Kills • ________________________________ Coastal Erosion Sea turtle nest exposed Hurricane Sandy 2013 Framework is impacted by storm damage but new growth occurs within light gaps What about Monsoons? From the Arabic mausim meaning season… Summer Southwest monsoon (Honjo and Weller, 1997) Winter Northeast monsoon Seasonal cycles are critical to biological cycles too… • Biological communities have adapted to seasonal cycles: • Gray whales __________ to Arctic waters in __________ to feed on ______ and other ________________ • Subsistence hunters in Alaska depend on annual migrations of marine mammals