The European North Atlantic rack [Ocean-Rack Trade, inward waves]

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cross-incline trade gauge ~ Ekman transport. NOCS wind speeds, Josey et al. (1998; ... over steep inclines (Celtic Sea (Pingree), W Scotland, W-T edge) ...

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Slide 1

The European North Atlantic rack [Ocean-Shelf Exchange, interior waves] John Huthnance Proudman Oceanographic Laboratory Liverpool, UK Motivation Context Processes and streams Estimating trade/models Maybe more about carbon cycling

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Motivation Global cycles maritime N  rack  essential creation 0.5 0.2 (Gt/y) (Walsh, 1991) (Wollast, 1993) OC spending vulnerability ~ 1 Gt/y ~ rack send out CO 2 discharge by upwelling, breath versus draw-down JGOFS-LOICZ C ontinental M argin T get some information about this later] Physical interests [including trade; accentuation for now] unique slant forms rack impact on sea and the other way around e.g. commitment to sea blending

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NE Atlantic zone Shelf has Varied introduction width for the most part 100-500 km smaller S of 40°N profundity < 200 m (~ break) aside from off Norway Canyons Irregular drift with crevices Fjords (north from ~ 55°) ~ Small stream input

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(Van Aken in Huthnance et al 2002) Upper ~ 500 m streams to S from Biscay Saline Mediterranean surge at 500 – 1500 m, against incline to N winter cooling  profound convection in Nordic oceans and N Biscay (  thick base layer) Adjacent Oceanic stream

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Along-slant ebbs and flows (RSDAS, Plymouth Marine Lab 15-21 Feb 1990) warm, salt NAW  slant ebb and flow Iberia and Biscay to Norway

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Flow to N at 56 ½ ° N (cm/s; W Scotland; Souza)

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Nordic Seas ebbs and flows Upper ~ 500 m flows to N in Rockall Trough & assist north NAW  Nordic oceans round Faroes, Iceland Moderate waterways & coastal ebbs and flows Baltic → NCC biggest

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Estimated transport past 62N McClimans

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Slope ebb and flow (ct'd) Bottom Ekman layer takes trade transport gHs/8f of arrange 1 m 2/s where s is steric slant H  - 1  y , ordinarily 10 - 7 (down-slant base stream for poleward slant ebb and flow) Instabilities - Eddies: Faroe-Shetland Channel -"SWODDIES" from slant ebb and flow off northern Spain (Pingree and LeCann, 1992) Capes, gulches, fluctuated rack width -nearby up-/down-welling, cross-slant trade e.g. Cape S ão Vicente & Goban Spur "overshoot" O(1 Sv)

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"Overshoot" at Goban Spur (Pingree et al. 1999)

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Wind-constrained stream/trade, m 2/s Irish-Norwegian rack & westerlies  downwelling (yet not reliably) solid winning westerlies, at the most. ~ 60°N tempest surges cross-incline trade evaluate ~ Ekman transport NOCS wind speeds, Josey et al. (1998; 2002) directions, standard deviations from Isemer & Hasse (1995)

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Wind-driven upwelling NE "exchange" winds → Summer upwelling off W Spain, Portugal, ↔ drift heading (Finisterre; less off Algarve) Filaments each → Exchange ~ 0.6Sv > τ/ρ f 6-12 Sep 1998

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Tides for the most part semi-diurnal streams on rack by and large > 0.1 m/s, locally > 0.5 m/s much water  retire inside 12.4 hours practically identical interior tidal ebbs and flows created locally over soak inclines (Celtic Sea (Pingree), W Scotland, W-T edge)

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Consequences of tides water conveyed by inward solitons (up to 1 m 2/s) nearby along-or cross-slant redressed stream commitment to long haul relocations shear scattering K ~ t D U 2 on the grounds that tidal momentum differs with profundity (grinding) t D ~ 10 3 s (Prandle, 1984) little impact unless U > 0.5 m/s Energy dissemination, blending (barotropic & inner tide)

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Faroe-Shetland Channel, interior tide vitality flux M2 appeared, equivocalness in baroclinic flux, slant super-basic Flux in non-direct hf waves tantamount with dispersal Slope sub-basic; energy has no place else to go, scatters Very factor through time (slant ebb and flow, swirls)

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Cascading Winter cooling or dissipation helped by absence of freshwater on rack  thick dilute  slant stream under gravity common falling fluxes locally 0.5 – 1.6 m 2 s - 1 noteworthy where introduce eg. Celtic Sea, Malin, Hebrides racks

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Celtic Sea ↓ Malin shelf↓ winter cooling

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Water trade gauges From vagabonds: Cross-slant scattering gauges north of Scotland ~ 360 m 2 s - 1 (Burrows and Thorpe, 1999) ~ 700 m 2 s - 1 (Booth, 1988) Current difference gauges ~ 0.01 m 2 s - 2 north of Scotland 0.01-0.02 m 2 s - 2 off Norway (Poulain et al., 1996)

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Estimated trade (NW Iberia) Summer (filaments) Winter Average Drifters scattering (Des Barton) ~ 870 m 2 s - 1 ~ 190 m 2 s - 1 ~ 560 m 2 s - 1 saltiness & along-incline stream (Daniualt et al. 1994) 500 m 2 s - 1  Exchange flux crosswise over 200m profundity contour 3.8 m 2 s - 1 (expect 26 km seaward scale; ~ supplant rack water in 10 days) watched rms. U cross-slant 19 mm/s in 200 m ≡ 3.8 m 2 s - 1 ! . . . . . . . above 200 m → 3.1 m 2 s - 1 Contributing procedures (m 2 s - 1 ) Up-/down-welling 3 0.6 Slope ebb and flow 2 ndy 1 1 Internal solitons 1 Eddies+cross-front 0.6 ??Total?? 5.6 2.2

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Exchange q', m 2 s - 1

Slide 21 into/hadleycentre/models/carbon_cycle/intro_global.html

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The rack ocean carbon pump Sea surface Photosynthesis Thermocline Shelf ocean Respiration Mixing Deep Ocean Vertical asymmetry in P-R drives air-ocean CO 2 contrast. Be that as it may, these oceans are all around blended in winter so need to evacuate C along the side Section Sea bed

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Observed North Sea air-ocean CO2 flux Thomas et al Science 2004: net CO2 drawdown in the North Sea

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Phytoplankton Pelagic Si N u t r i e n t s Dino-f Pico-f Diatoms NO 3 Flagell - ates Particulates DIC NH 4 Bacteria PO 4 Dissolved Hetero-trophs Micro-Meso-Consumers Suspension Feeders D e t r i t u s Oxygenated Layer N u t r I e n t s Aerobic Bacteria Meio-benthos Deposit Feeders Redox Discontinuity Layer Anaerobic Bacteria Reduced Layer Benthic POLCOMS-ERSEM: Atlantic Margin Model 3D coupled hydrodynamic biological community show

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The AMM recreation Developed from the NCOF operational model POLCOM-ERSEM ~12 km determination, 42 s-levels 1987 turn up, 1988 to 2005 – 18 years ERA40 + Operational ECMWF Surface constraining ~300 waterway streams 15 tidal constituents Time shifting (spatially consistent) atmos pCo 2 Mean yearly cycle for Ocean limits EO SPM/CDOM Attenuation River supplement and DIC Recent improvements: Run10 34 to 42 s-levels COARE v3 surface compelling GOTM turbulence display

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Carbon Budget High creation Low/Conv. transport Low air-ocean flux High/Div. transport High air-ocean flux

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The misfortune term The rack wide Carbon spending plan In-natural Small Difference = internment Organic Acidification Equilibrium

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Carbon send out Horizontal shift in weather conditions is the overwhelming misfortune term Net advective loss of carbon (subtracting waterways): 0.9x10 12 mol C yr - 1 Net entombment: 0.02x10 12 mol C yr - 1 But to be a powerful sink must leave the rack to DEEP water Otherwise may re-equilibrate with air.

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How to get the Carbon off the rack ? The principle ebb and flow out of the north ocean is a surface momentum Shelf-edge: "frictional" procedures: e.g. Ekman depleting; beach front downwelling After Turrell et al 1994

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Volume fluxes: above and underneath 150m Above: 1.89Sv Below:- 1.94Sv This is a downwelling rack

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Conclusions 1: Carbon Cycle The NW European rack is a net sink of barometrical CO2 Shelf edge areas have a tendency to be solid sinks Open stratified districts are impartial or weaker sinks. Seaside areas are either sources or sinks The course is crucial in keeping up the rack ocean pump Tidally dynamic rack oceans need 'send out generation' or entombment Regions of powerless or focalized DIC transport have extremely frail air-ocean fluxes There is no basic connection amongst profitability and air-ocean CO2 flux

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Conclusions 2: Modeling the air-ocean CO2 flux in rack oceans requires exact Circulation Mixing Chemistry Biology Currently under-gauge the rack ocean air-ocean flux The harmony amongst sea and rack essential creation is not yet very much spoken to in these reenactments The close waterfront locale is especially imperative: can go about as either sink or source - additionally the most difficult Complex optics Needs expanded even determination Land-ocean fluxes dubious

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Role of the slant ebb and flow Acts to recharge on-rack supplements (positive relationship with summer natural carbon) Acts to evacuate DIC (negative relationship with summer inorganic carbon) Together it drives the mainland rack carbon pump.

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Global commitment (in context) 0.01 pg Cyr - 1 of ~2 pg Cyr - 1 Biological pump 1.5 pg Cyr - 1 of ~90 pg Cyr - 1 Downwelling flux How does this up-scale to rack oceans all around ?

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Outline/conclusions Prevalent along-slant stream poleward not uniform, perhaps not "persistent" maybe secured by various surface stream Strong wind driving up-and down-welling filaments increment trade Strong tidal ebbs and flows and blending on wide retires Relatively little trade in vortexes Moderate freshwater and stratification except Norwegian Coastal Current Local redressed tides, solitons, falling Overall trade 2-3 m 2 s - 1