國立中山大學學位論文典藏.PDF

Size: px

Start display at page:

Download "國立中山大學學位論文典藏.PDF"

鱼经
5 years ago
Views:

1 Numerical simulation of topography and stratification effects to the internal tide in Gaoping Submarine Canyon

2 i

3 POMPrinceton Ocean Model 1 TPXO 6. MMK1 3~ ~00 Energy Flux ii

4 Abstract It is generally understood that tidal currents dominated the flow field in many submarine canyons, and internal tide may be an order of magnitude more energetic than that of barotropic. The internal tide can be generated and amplified in a marine environment with the strong vertical density interface. The barotropic tides were known to play the dominant role in driving the internal tides at the topographic relief or shelf break. This research tries to look at the mechanisms of internal tides generation and propagation in the Kaoping Submarine Canyon off southwestern Taiwan, using Princeton Ocean Model (POM) with different settings. The model was tested with bottom topography of flat, a slope and real water depth, with and without vertical stratifications. The model settings are grid size 500m, simulate period days, radiation boundary condition at 4 sides. The model forcings are sea level variations at the west side, both semidiurnal tide (M) and mixed tide (MK1) based on OSU tidal model TPXO 6.. The results suggest that the offshore M tidal forcing can generate large internal tidal currents within the canyon with vertical density stratification. The internal tidal currents at the upper-layer of the canyon lag that of lower-layer 3~5 hours. There is no time lag and no amplification of current in the canyon if there is no stratification. There is a transition zone of minimum flow at depth of about m. Below the interface, the amplitude of semidiurnal internal tidal current increased with water depth in the canyon. The simulated density contours suggest a 10m amplitude vertical fluctuation center at 150m depth, with 5 temperature fluctuation. The computed baroclinic energy flux indicates iii

5 that the energy in lower layer of the canyon is stronger than that of upper layer. The high energy flux appears at the canyon foot and rim, and propagates along the canyon axis landward. iv

6 ... i... ii Abstract... iii...v... vii... ix (energy flux) v

7 POM...44 vi

8 TPOX CTD LADCP 600m M MK M M...7 vii

9 3-7 M MK K1 MK N Montery Bay...39 viii

10 -1 case...14 ix

11 1-1 Gaoping or Kaoping Submarine Canyon, KPSC 1-1 Liu et al.1998 VU -SChow et al

12 sb-ADCP Wang et al

13 1-Wang et al Wang et al., 008; Lee et al., 009 3

14 1-, Wang et al., 008 4

15 1- M 1.4 RidgeContinental Shelf SlopeSill Internal Tide : Garrett

16 1-4Garrett, 003 Holloway et al.,1999; Kunze et al., 00; Laurent et al.,00 Simmons et al., 004 Merrifield et al., 00 6

17 Hotchkiss and Wunsch198Hudson New and Pingreet1990 Bay of Biscay García Lafuente et al.1999alboran Sea La Linea Submarine Canyon 0.5m/s Petruncio et al.1998, 00Monterey Bay 50 Pereira et al.005s-coordinates Rutgers University Model, SCRUM 1-5 7

18 1-5Pereira et al., 005X Y MO1 MO1 8

19 1-3 5 Lee et al Jeng et al., 1996, Huh et al., 008 POMPrinceton Ocean Model MMK1 9

20 -1 POM Princeton Ocean Model, POM, Blumberg Mellor Blumberg and Mellor, 1987POM POM Second moment turbulence closur sub-model 4. sigma 10

21 5. Arakawa-C 6. Explicit Implicit 7. Free Surface External mode Barotropic mode Internal mode Baroclinic mode POM -1 11

22 -1 (Mellor,004) 1

23 (1) 100m t I () (3) -800 m 000m000 m 0 80 m coordinate 000 t E 13

24 OSU MMK1 -. TPXO 6. 1/1 x 1/1 勒 Oregon State University,OSUGary Egbert00 T/PTOPEX/Poseidon 66 雷 OSU north-west pacific -4 1/1 x 1/1 ESR (Earth and Space ResearchLana Erofeeva003 TMD Tide Model Driver MK1 M K M MK1 gravity-wave radiation boundary condition 14

25 u t η ± c = 0 c = gh x φ ± c t i h φ = 0φ uvt s x CR170008/01/10 11 CTD case M 0. x =100m t =15 sec 100*100*1 t E =0.5 sec, I M x =100m t E =0.5 sec, t I =15 sec 0. 14*5*1 M x =500m t E =0.5 sec, t I =30 sec 14*5* Hr MK1 M Hr K Hr 15

27 -4 TPOX CTD 17

28 -3 POM 008 /10~/0 M -6 MK1-6 POM r

29 600m 008/01/0~008/03/0Long-range ADCP M -7 M /14~/17 Long-range ADCP Long-range ADCP -M M r LADCP 600m 19

30 A 3-1B AM 3-u 3-1C B100~00 0

31 100~003~5 100~ C MK13-4M 1M MK1 1

32 A B C 3-1 B C

33 A m B C 3--B C 3

34 A B m C 3-3-M B 3~5 C 4

35 3-4M - MK1 5

36 3- M3-5 M3-6MK M K1M MWang et al. 008M 3-5 6

37 3-6 M M 30 cm / s 3-7 M MK

38 3-8 K1 MK1 M 8

39 u v A CD ~ Petrincio et al.1998, 00 Montery Bay 50 Wang et al Pereira et al A Pereira 1-5 9

40 3-9A 30

42 3-1 3

43 N N dρ = g N ρ ρ dz ~00 1/sec 3-13 N 33

44 3-4 (energy flux) energy flux (Munroe, 005) k pb( i, j, k) = ( α ( i, j, k) β ( i, j, k)) * g * γ * dh( k') k ' = 1 : α ( i, j, k) = ( ρ 1000) / γ ρ g γ β ' ' dh ( k ) = ( h( i, j) el( i, j)) * dh( k ) hel : EF _ x( i, j) = kb k = 1 pb( i, j, k ) ub( i, j, k ) dh( k ) EF _ y( i, j) = kb k= 1 pb( i, j, k) ub( i, j, k) dh( k) ub, vbua, va kb ub( i, j, k) = u( i, j, k) ua( i, j) vb( i, j, k) = v( i, j, k) va( i, j) 34

45 3-14; A Xu et al.00 Montery Bay Petruncio et al.1998 Kunze et al.00 Montery Bay Jachec et al.006 Montery Bay

46 A 3-14m 36

47 3-15U 37

48 3-16Montery Bay Jachec et al., 006 Kunze et al

49 39

50 40

51 POM Chow, J., J. S. Lee, C. S. Liu, B. D. Lee, and J. S. Watkins, 001. A submarine canyon as the cause of a mud volcano-liuchieuyu Island in Taiwan. Marine geology, 176, Garrett, C., 003. Internal Tides and Ocean Mixing. Ocean Science, 41

52 301(5641), Jachec, S.M.,O.B. Fringer,M.G. Gerritsen, and R.L. Street, 006, Numerical simulation of internal tides and the resulting energeticswithin Monterey Bay and the surrounding area. Geophysical Research Letters, 33, L1605, doi:10.109/006gl06314, Kunze, E., L. K. Rosenfeld, G. Carter, and M. C. Gregg, 00, Internal waves in Monterey Submarine Canyon, Journal of Phyical Oceanography, 3, García Lafuente, J., T. Sarhan, M. Vargas, J.M. Vargas and F. Plaza, Tidal motions and tidally induced fluxes through La Linea submarine canyon, western Alboran Sea. Journal of Geophysical Research, 104, C, Lee, I. H., R. C. Lien, J. T. Liu, and W. S. Chuang, 009. Turbulent mixing and internal tides in Gaoping (Kaoping) Submarine Canyon,Taiwan. Journal of Marine Systems, 76, , doi: /j.jmarsys Lee, I. H., Y. H. Wang, J. T. Liu, W. S. Chuang, and J. Xu, 009. Internal Tidal Currents in the Gaoping(Kaoping)Submarine Canyon. Journal of Marine Systems, 76, , doi: /j.jmarsys Liu, C. S., S.Y. Liu, S.E. Lallemand, N. Lundberg, and D. Reed, 1998, Digital Elevation Model Offshore Taiwan and Its Tectonic Implications. TAO, 9(4), Liu, J. T., and H. L. Lin, 004. Sediment dynamics in a submarine canyona case of river sea interaction. Marine Geology, 07, Liu, J. T., J. J. Hung, H. L. Lin, C. A. Huh, C. L. Lee, R. T. Hsu, Y. W. Huang, and J. C. Chu, 009. From suspended particles to strata: The fate of terrestrial substances in the Gaoping (Kaoping) submarine canyon. Journal of Marine Systems, 76, , doi: /j.jmarsys Merrifield, M. A. and P. E. Holloway, 00, Model estimates of M internal tide energetics at the Hawaiian Ridge, Journal of Geophysical, 107(C8), doi: /001JC Munroe, J. R. and K. G. Lamb, 005. Topographic amplitude dependence of internal wave generation by tidal forcing over idealized three-dimensional topography. Journal of Geophysical Research, 110(c), 1-14, doi:10.109/004jc

53 New, A. L. and R. D. Pingreet, Evidence for internal tidal mixing near the shelf break in the Bay of Biscay, Deep-Sea Research, 37(1), Pereira, A. F., A. L. Belem, B. M. Castro and R. Geremias, 005. Tide-topography interaction along the eastern Brazilian shelf, Continental Shelf Research, 5, Petruncio, E. T., L. K. Rosenfeld, and J. D. Paduan, Observations of the internal tide in Monterey Canyon. Journal of Physical Oceanography, 8, Petruncio E. T., J. D. Paduan, L. K. Rosenfeld, 00. Numerical simulationof the internal tide in a submarine canyon. Ocean modeling, 4, 1-8. Simmons, H. L., R. W. Hallberg and B. K. Arbic, 004. Internal wave generation in a global baroclinic tide model, Deep-Sea Research II, 51, Wang, Y. H., I. H. Lee, and J. T. Liu, 008. Observation of internal tidal currents in the Kaoping Canyon off southwestern Taiwan, Estuarine, Coastal and Shelf Science, 80, , doi: /j.ecss

54 44 POM governing equations POM z equation of state ( ) T,S ρ ρ = hydrostatic equation ρ = p gd continuity equation = 0 ω η z DV y DU x momentum equation x = 0 0 ' ' ' ' ' ρ ρ ρ η ω x M F d x D D x gd U D K x gd fvd U y UVD x D U t UD y = 0 0 ' ' ' ' ' ρ ρ ρ η ω y M F d y D D y gd V D K y gd fvd V y D V x UVD t VD conservation equation for temperature

55 45 z R F T D K T y TVD x TUD t TD T H = ω conservation equation for temperature S H F S D K S y SVD x SUD t SD = ω turbulence kinetic energy q l H M q F B l D q K g V U D K q D K q y VD q x UD q t D q = 3 0 ~ ρ ρ ω turbulence length scale ( ) l l H M q F B D q W K g E V U D K E l l q D K l q y lvd q x lud q t ld q = ~ ρ ρ ω η η = H z -1< s < 0 H η z z η 0 z H 1 ρ potential density T potential temperature

56 S p R short wave radiation flux g D H η U,V ω s f ρ 0 reference density ρ ρρ mean ρ mean z z ρ ' q l k M vertical kinematic viscosity k H vertical diffusivity k q 46

57 F x, F y vertical turbulence diffusivity horizontal viscosity term F F, F, F T, S q l horizontal diffusion term W ~ wall proximity function B, E 1 E1, 3 K M = qls M K H = qls H K q = qls q S M S S H M S H K M H K K q Richardson number A 1 Ps Pb [ 1 ( 3A B 18A A ) G ] = A 1 1 H 6 A1 Ps Pb [ 1 9A A G ] S [( 18A 9A A ) G ] = A 1 3C 1 H H 1 1 H ( A A, B, B, C ) ( 0.9,0.74,16.6,10.1,0.08) 1, 1 1 = B 1 ε B 1 ε G l = q g ρ 1 ρ0 z Cs H p Richardson Number z 47

58 48 = x v y u A H y x u A H x F M M x = y v A H y x v y u A H x F M M y M A horizontal kinematic viscosity = y A H y x A H x F H H φ φ φ φ T S q l q H A horizontal heat diffusivity POMexternal mode time step E t internal mode time step I t Courant-Friedrichs-LevyCFL a.) y x C t t E

59 C t = gh U max gh max b.) CFL U t I 1 1 C x 1 y 1 C T = C U Cinternal gravity wave max U max advective speed t I 1 1 4A x 1 y 1 A = A = AH AM t I 1 f 1 = Ωsin Φ Ω Φ 49

國立中山大學學位論文典藏.PDF

國立中山大學學位論文典藏.PDF Observations of Volume Transport in the Taiwan Strait I II 2.04 ) / ( 13.74 ) ( 2 + = m N Sv III Abstract Several cruises of current measurements along various cross-taiwan Strait transects were conducted