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Global Ocean Circulation (2). Wind-driven gyre-scale circulation of the surface ocean and upper thermocline Global heat and freshwater water transport, conservation properties Water mass properties, polar convection and mixing, tracers, global thermohaline circulation.
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Global Ocean Circulation (2) • Wind-driven gyre-scale circulation of the surface ocean and upper thermocline • Global heat and freshwater water transport, conservation properties • Water mass properties, polar convection and mixing, tracers, global thermohaline circulation Focus on conservation principles:Balancing heat, salt, etc. into and out of ‘boxes” (control volumes) MS320 Lecture 2008-10-27
http://ferret.pmel.noaa.gov/NVODS/servlets/dataset?catitem=5707http://ferret.pmel.noaa.gov/NVODS/servlets/dataset?catitem=5707
http://ferret.pmel.noaa.gov/NVODS/servlets/dataset World Ocean Atlas 1998 Annual
Positive implies ocean warming Warming everywhere – of course
Positive implies ocean warmingNegative implies ocean cooling Why is net upward longwave less in WPWP?
Positive implies ocean cooling Western boundary current have greatest air-sea temperature difference
Positive implies ocean cooling COADS monthly climatology http://ferret.pmel.noaa.gov/NVODS/servlets/dataset?catitem=18098
RT = Radiation total at the top of the atmosphere from Earth Radiation Budget ExperimentOT = ocean transport from net air-sea heat fluxAT = atmospheric transport (calculated from RT – OT)
http://ferret.pmel.noaa.gov/NVODS/servlets/dataset?catitem=5707http://ferret.pmel.noaa.gov/NVODS/servlets/dataset?catitem=5707
Write equations for conservation of (1) salt (2) volume ? E-P-R = 4.6 x 104 m3/s
http://ferret.pmel.noaa.gov/NVODS/servlets/dataset?catitem=5707http://ferret.pmel.noaa.gov/NVODS/servlets/dataset?catitem=5707
Bars show direct estimates from oceanographic cross-sections
Heat transport from ocean observations constrained by conservation principles Atlantic has northward heat transport everywhere
Atlantic heat transport is so different because there is a vertical over-turning circulation that shows up clearly in patterns of salinity
Low salinity in north but no large negative E-P. What other freshwater sources are there? South North
Shaded implies net precipitation Earth’s water budget is dominated by E-P over the ocean (80% occurs there) Precipitation minus evaporation (m year-1) Max P-E in East Pacific is not exactly over the equator – why?