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Modele maree Oceanique Finite Element System FES 2004  FES 2012 Rmsdiff semi-annual as large as 3cm open ocean: importance of luni solar K1 aliasing.

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Presentation on theme: "Modele maree Oceanique Finite Element System FES 2004  FES 2012 Rmsdiff semi-annual as large as 3cm open ocean: importance of luni solar K1 aliasing."— Presentation transcript:

1 Modele maree Oceanique Finite Element System FES 2004  FES 2012 Rmsdiff semi-annual as large as 3cm open ocean: importance of luni solar K1 aliasing

2 10cm, K1 a: Equilibrium semi-diurnal tides SI- data 1 17cm, M2 8cm, S2 phaseamplitude phase 60cm,M2 24cm,K1 c: M2 and K1 dynamic estimates b: Equilibrium diurnal tides amplitude

3 2.8cm SI- data 2 phase a: Equilibrium long period tides amplitude b: amplitude Mf dynamic estimate 3.02 cm, Mf; 1.55 cm, Mm; 1.35 cm, Ssa; 2.07 cm, Sa c: total tidal transport (kg m 2 /s)

4 60cm,M2 24cm,K1 2.8cm, Mf c: dynamic M2 and K1 tidal amplitudes SI- Data 2 phase c: dynamic Mf tidal amplitude b: equilibrium long period tides amplitude 3 cm, Mf 1.5 cm, Mm

5 SI-persp3 (cm/s) transport current maxNorth maxNorth (m2/s) S N N S Hemispheric averages of K1 meridional hour K1 LuniSolar tidal elevation (cm) in Arctic

6 Ray et al., 2005 Tidal Energy Flux Vector M2 K1 Semi-diurnal (12h25mn) Diurnal (23h56mn) Lunar Luni-Solar Min (1997)/ Max (2006) Lunar Inclinaison  nodal factors: with inclination, K1 increases 3 times more than M2 decreases  Role K1 increase (18.6yrs) on decadal climate -at high lat where K1 big (Ray, 2007), AND -in tropics because of Yanai increase

7 SSS SST winds QSCAT tide Courtesy of Dr. Kelly (OVWST, 2007) …..……….…. Latitudes …………….. …….. 180ºW………… Longitudes ……..90ºW Trade winds QSCAT diff=SEC c: Zonal components d: Meridional components 180ºW…………..longitudes……..90ºW Trade winds QSCAT diff=NECC diff a: mean differences: daily TAO (winds) – QSCAT (OVW) b: mean Ocean currents from drifters at 15m NECC SEC North South Equator

8 Solar climatology of OST (cm) October – April ECCO ECCO July-Jan October – April ECCO – (QSCAT) NORTH average (cm)SOUTH average (cm) month TPJ O(QSCAT) TPJ O(QSCAT) SI- data4

9 Total tidal transports (kg m 2 /s) 3 hours apart

10 On average between 60º latitudes, North Pac is 22% deeper than South On average between 25º and 60º latitude: 66% area is ocean in South, 43% area is ocean in South

11 V transport K1 maxNorth and is bigger than maxSouth (m2/s) horizontal axis duration = 24h ~ K1 tidal cycle (period=23h56mn) = annual cycle for K1 detected by QSCAT or ASCAT Significant phase difference (4hours) between currents and transport North budgets because averaged North Pacific deeper than South. Tidal current values are provided by TPXO7.2 on 1 Nov 2007 from 00h:30 to 23h:30.

12 a: LOD-moon time series b: LOD_moon wavelet c: LOD_sun wavelet days SI- data 5

13 a: Last and First Quarter around September equinoxes ~2 weeks apart * * * b: New and Full moon during June and December solstices * ~6 months apart ecliptic plane The Earth Moon Mass Center (EMMC) remains in the ecliptic plane. The Earth mass center is 4670 km away from the EMMC.

14 Energy of the horizontal and vertical acceleration speeds Fig 11 days a: zonal b: meridional c: vertical

15 3.5 TW is the tidal power dissipated by the oceans 3.4 TW is the average total (gas, electricity, etc.) power consumption in US in TW is the tidal power used by oceans to mix and maintain stratification TW is the power induced by OVW stresses in the oceans ( 90% are dissipated in the upper 100m )

16 M2:period=12h25mn K1: period=23h56mn S2: period=12h 2D Vectors (instant) u, v, w =sqrt(u2+v2) speed (Ex, Ey) =  g Sum_period{ (u,v)H(  +  s) dt } / period Units? Ocean Wind Stress (TX,TY)… Pascal (kg m/s2)  s=  body+  load Ocean Vectors of Work done by the (air-sea) Wind Stress on the ocean circulation: (OVWWx,OVWWy) =Sum_surf*time {(TX*u+TY*v) dx.dy.dt } OVWW: the biggest unknown: between 0.4TW and 1.7TW Ocean Tidal Energy (EX,EY)… (kg m2/s) = Sv/m

17 Tidal astronomic forcing M2 K1 semi-diurnal symmetric, diurnal antisymmetric the ocean responses loose symmetry because waters are squeezed to flow between the ocean bottom, its surface and the continents. semi-diurnal (12h25mn) diurnal (23h56mn

18 QSCAT OVW stress TPJ wave/swell Tropical Swell pools % 72% Indian and Pacific warm pools 32º 13º 24º 3 1 2

19 The difference between model and observed MSL is too big to be real. It corresponds to a change in Earth’s oblateness which is incompatible with the observed range of LOD variations. cm model forced by QuikSCAT vectors (CORE2): courtesy of Dr. Large (NCAR), OVWST, 2008 mean Sea Level simulated by OGCM forced by QuikSCAT vectors relative to observed MSL 14.7 days apart New Moon in North around June solstice Full Moon In South in June-July * *

20 What energy vector are detectable by scatterometers for climate? (U,V) winds in (m/s)…  Stress (TX, TY) in (kg/m/s2) =  (u’w’, v’w’) (vertical transfer of turbulent momentum) =  CD Wa (Ua, Va ) (CD: drag coefficient) =  CD Wshear (Ushear, Vshear) where (Ushear, Vshear) = (atmosphere – ocean) horizontal flows (Ua-Uo-0.8Uorb) = u*/k ln[….z/z0…]  TX (Va-Vo-0.8Vorb) = v*/k ln[….z/z0…]  TY where (Uorb, Vorb) =Vector of orbital wave velocities Energy in (kg*m2/s2): (OVWEx, OVWEy) and (TideOVEx, TideOVEy) (Sum_surf*time {(TX*Uo, TY*Vo) dx.dy.dt } ) (  g Sum_period{(Udx,Vdy) *H*(  +  s) ) dt })  2D- vectors: OVW work rates (per  t, per length) in (kg*m/s3= Watt/m) 1) over which  t do we choose to compute the OVW work rates? 2) over which thickness  z do we choose (u, v) ocean surface? 3) we need the (Uo, Vo) due to p_atmos, tides and fast (TX,TY) as well? 4) we need the work rate via wave/swell too.  0,H1/3 altimeter?  Issues so far unresolved due to ocean-air curl/mass discontinuities at interface between 2 thin shells at the surface of the Earth. Emerging solution: 3D- vectors (OA)Momentum in (kg*m2/s)

21 d: 2000:2004 mean OST: model forced by QSCAT– observations SI- data 3 a: mean meridional OVW difference: ECMWF - QSCAT cm m/s V QSCAT (200 kg m 2 /s) V ECMWF - V QSCAT (m/s) 60S EQ 60N +1 dyn/cm longitude latitude m/s QSCAT 62 QSCAT 65 QSCAT 66 ERS 61 FSU 10 NCEP 15 c: zonal averages of meridional winds, QSCAT, differences and tides b: OVWy stress along 6ºN winds QSCAT diff tide S Equatpr N


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