Breathers of the Internal Waves Tatiana Talipova in collaboration with Roger Grimshaw, Efim Pelinovsky, Oxana Kurkina, Katherina Terletska, Vladimir Maderich Institute of Applied Physics RAS Nizhny Novgorod, Russia Nizhny Novgoro Technical University Institute of Mathematical Machine and System Problems, Kiev Ukraine UK Do internal solitons exist in the ocean? Lev Ostrovsky, Yury Stepanyants, 1989 INTERNAL SOLITARY WAVE RECORDS Marshall H. Orr and Peter C. Mignerey, South China sea J Small, T Sawyer, J.Scott, SEASAME Malin Shelf Edge Nothern Oregon Observations of Internal Waves of Huge Amplitudes Internal waves in time-series in the South China Sea (Duda et al., 2004) Where internal solitons have been reported (courtesy of Jackson) The horizontal ADCP velocities (Lee et al, 2006) Internal Solitary Waves on the Ocean Shelves • Most intensive IW had been observed on the ocean shelves •Shallow water, long IW, vertical mode structure • There is no the Garrett-Munk spectrum •There is 90% of presence of the first mode Mode structure Brunt - Vaisala, frequency, sec-1 0 0.004 0.008 0.012 0 0.016 -1 -0.5 0 0.5 1 (z) 0 N(z) 40 40 Second mode 80 80 120 120 Z, 160 м d dz First mode 160 Eigenvalue problem for and c 2 d 2 ( c U ( z )) N ( z ) 0, dz (0) ( H ) 0 max 1 Theory for long waves of moderate amplitudes u u u 2 u u 1u 3 0 t x x x 3 Gardner equation •Full Integrable Model Coefficients are the functions of the ocean stratification Gardner’s Solitons A u ( x, t ) 1 Bcosh( ( x Vt )), sign of 1 2 6 A , B 1 2 1 <0 Limited amplitude alim = /1 1 >0 V 61 2 2 2 A a 1 B Two branches of solitons of both polarities, algebraic soliton alim = -2 /1 , cubic, 1 Positive and Negative I Solitons 1 II Positive algebraic soliton Negative algebraic soliton quadratic α III IV Negative Solitons Positive Solitons Sign of the cubic term is principal! Gardner’s Breathers cubic, 1 > 0 = 1, = 12q, 1 = 6, where q is arbitrary) lch(Ψ )cos( ) - kcos(Φ)sh(κ ) u2 at an x lsh (Ψ ) sin( ) k sin(Φ)ch(κ ) and are the phases of carrier wave and envelope k ( x wt ) 0 , κ l ( x vt) κ 0 propagating with speeds w k 2 3l 2 , v 3k 2 l 2 There are 4 free parameters: 0 , 0 and two energetic parameters Pelinovsky D&Grimshaw, 1997 l ik Φ iΨ tan 2 q 1 sh(2Ψ ) sin(2Φ) k q 2 lq 2 2 2 2 2 2 2 cos (Φ)ch (Ψ ) sin (Φ)sh (Ψ ) cos (Φ)ch (Ψ ) sin (Φ)sh (Ψ ) Gardner Breathers im→ 0 4 real > im 4 2 ui 0 real < im 2 3.803 4 10 10 8 6 4 2 0 xi 2 4 6 8 10 10 Breathers: positive cubic term 1 > 0 Breathers: positive cubic term 1 > 0 Numerical (Euler Equations) modeling of breather K. Lamb, O. Polukhina, T. Talipova, E. Pelinovsky, W. Xiao, A. Kurkin. Breather Generation in the Fully Nonlinear Models of a Stratified Fluid. Physical Rev. E. 2007, 75, 4, 046306 Do Internal Breathers Exist in the Ocean? Why IBW do not obserwed? 1 > 0 Grimshaw, Pelinovsky, Talipova, NPG, 1997 South China Sea 1 There are large zones of positive cubic coefficients !!!! Nonlinear Internal Waves From the Luzon Strait Eos, Vol. 87, No. 42, 17 October 2006 Russian Arctic Sign variability for quadratic nonlinearity is ordinary occurance on the ocean shelves 1 Positive values for the cubic nonlinearity are not too exotic on the ocean shelves Lee, Lozovatsky et al., 2006 Alfred Osborn “Nonlinear Ocean Waves & the Inverse Scattering Transform”, 2010 Mechanizms Solitary wave transformation through the critical points • Breather as the secondary wave is formed from solitary wave of opposite polarity when the quadratic nonlinear coefficient changes the sign • Breather is formed from solitary wave of opposite polarity when the positive cubic nonlinear coefficient decreases Modulation instability of internal wave group Transformation of the solitary wave of the second mode through the bottom step Quadratic nonlinear coefficient changes the sign Breather formation at the end of transient zone 1 = 0.2 Grimshaw, Pelinovsky, Talipova Physica D, 1999 =+1 15 0 -15 15 =0 0 -15 15 = - 0.6 0 -15 15 =-1 0 -15 225 250 275 x 300 230 240 250 260 x 270 280 290 Horizontally variable background H(x), N(z,x), U(z,x) x 0 (input) ( , x) dx t , xx c( x) ( , x) Q( x) Q - amplification factor of linear long-wave theory Resulting model Q c02 (c0 U 0 )( d 0 / dz ) 2 dz c 2 (c U )( d / dz ) 2 dz ξ αQ α1Q 2 2 ξ β 3ξ ( 2 ξ 2 ξ ) 4 0 3 x c c τ c τ c, m/s Model parameters on the North West Australian shelf 2 Holloway P., Pelinovsky E., Talipova T., Barnes B. A Nonlinear Model of Internal Tide Transformation on the Australian North West Shelf, J. Physical Oceanography, 1997, 27, 6, 871. 1 , m3 /s 0 12000 6000 0 Holloway P, Pelinovsky E., Talipova T. A Generalized Korteweg - de Vries Model of Internal Tide Transformation in the Coastal Zone, 1999, J. Geophys. Res., 104(C8), 18333 -0.012 0.0004 1 , m s -1 -1 -1 , s 0 0.012 0 -0.0004 Q -0.0008 4 2 H,m 0 0 500 0 40 80 x, km Grimshaw, R., Pelinovsky, E., and Talipova, T. Modeling Internal solitary waves in the coastal ocean. Survey in Geophysics, 2007, 28, 2, 273 Internal soliton transformation on the North West Australian shelf Modulation Instability of Long IW Grimshaw, D Pelinovsky, E. Pelinovsky, Talipova, Physica D, 2001 Envelopes and Breathers Weak Nonlinear Groups u( x, t ) A( , ) exp(i ) A2 ( , ) exp(2i ) A0 ( , ) c.c. 2 kx t ( x cgr t ) 2 t 2 ε << 1 2 2 A2 A A0 A 2 2 6k 3k Nonlinear Schrodinger Equation A A 2 i 3k 2 k | A | A 2 0 1 2 6k 2 cubic, cubic, 1 focusing Wave group of large amplitudes Wave group of weak amplitudes | | 2 A > Acr 3 41 Wave group of large amplitudes quadratic, Bendjamin- Feir instability in the mKdV model 0 1 > 0 (x,0) = a(1+mcosKx)coskx Twenty satellites Twenty satellites just fulls the condition for a narrow initial spectrum. The evolution of the wave field with Amax = 0.5 is displayed below. The initial wave field consists of eight modulated groups of different amplitudes and each group contains 9-15 individual waves. t = 0, t = 400 R. Grimshaw, E. Pelinovsky, T. Taipova, and A. Sergeeva, European Physical Journal, 2010 Amax = 1.2 t=0 t = 150 An increase of the initial amplitude leads to more complicated wave dynamics. The breathers formed here are narrower than in the previous case (3 - 5 individual waves). The largest waves here are two individual waves, and are not a wave group. SAR Images of IW on the Baltic Sea а б Red zone is 1 > 0 1, m-1s-1 Baltic sea 0.00040 0.00000 -0.00040 , s-1 0.01 0.005 Q 0 2 1 0 , m3/s 1000 500 0 c, m/s 1 0.5 depth, m 0 0 30 60 0 40 80 120 160 x 1, m-1s-1 Focusing case We put = 0.01 s-1 0.00000 -0.00040 0.01 , s-1 cr, sec -1 0.00040 0.016 0.005 Q 0 2 1 0.012 0 , m3/s 1000 0.008 500 0 c, m/s 1 0.004 0.5 depth, m 0 0 0 40 80 x, km 120 160 0 30 60 0 40 80 120 160 x 0.00040 0.00000 -0.00040 0.01 , m , s-1 20 1, m-1s-1 A0 = 6 m 0.005 Q 0 2 10 1 0 , m3/s 1000 0 500 0 c, m/s 1 -10 0.5 depth, m 0 -20 0 2 4 t, hour 6 0 30 60 0 40 80 120 160 x 1, m-1s-1 0.00000 -0.00040 0.01 , m , s-1 20 0.00040 0.005 Q 0 2 10 1 0 , m3/s 1000 0 500 0 c, m/s 1 -10 0.5 -20 0 2 4 t, hour 6 depth, m 0 0 30 60 0 40 80 120 160 x 1, m-1s-1 No linear amplification Q ~ 1 0.00000 -0.00040 0.01 , s-1 20 , m 0.00040 0.005 0 2 Q 10 1 0 , m3/s 1000 0 500 0 c, m/s 1 -10 0.5 -20 0 2 4 t, hour 6 depth, m 0 0 30 60 0 40 80 120 160 x Interaction of interfacial solitary wave of the second mode with bottom step Terletska, Talipova, Maderich, Grimshaw, Pelinovsky In Progress Numerical tank Breaking parameter h2+/|ai | = 12 cm, H = 23 cm b = 2.17 Slow soliton and some breathers of the first mode plus intensive solitary wave of the second mode are formed after the step CONCLUSIONS Mechanisms of surface rogue wave formation can be applied for internal rogue wave formation Dynamics of internal waves is more various than dynamics of surface waves Additional mechanisms of internal rogue wave formation connected with variable water stratification are exists