• Wave-tracking Experiment to Assess NLIW Generation, Structure, Evolution and Dissipation

• Detection of NLIW by Seafloor Pressure Measurement

bottom landers with high-res pressure sensors

Moum

Named Waves Tracked• Alfred• Betty• Carlton• Debby• Elvin• Florence• George• Holly• Isaac• Jasmine• Kevin• Lola• Mika• Natalie• Oscar • …• Anya

NLIWI/SW06R/V Oceanus30 July – 26 Aug 2006

Science Party

Jim Moum OSUAlexander Perlin OSUGreg Avicola OSUEmily Shroyer OSUSam Kelly OSUMike Neeley-Brown OSURay Kreth OSU

Karen Fisher Los AlamosDezhang Chu WHOIDoris Leong DalhousiePaul Heslinga Falmouth Academy

approaching wave train – < 5 kt windsview from flying bridge

Mika

Tonya / wave group interaction group-group interactions

wave-wave interactions

SW37

SW38

SW39SW40

Oops! accidental sound source 02 August 2006 23:04:54

high turbulence at interface

interfacial jets?

Shipboard profiling measurements

Varicose waveJasmine

Seafloor pressure measurements of nonlinear internal waves, submitted to J.Phys.Oceanogr., December 2006 (Moum & Nash)

Shoaling nonlinear internal waves: transition from depression to elevation waves. in prep, J.Phys.Oceanogr. (Shroyer, Moum & Nash)

Emily Shroyer

Knorr

Knorr

Wave Florence

120 kHz backscatter

successive transits along 300/120, 0.5 nm SW of main array axis

Wave Florence

pre-wave state

120 kHz backscatter

successive transits along 300/120, 0.5 nm SW of main array axis

Wave Florence

1200 kHz backscatter

successive transits along 300/120, 0.5 nm SW of main array axis

Wave Florence

Wave Florence

Wave Florence

Wave Florence

Wave Florence

Wave Florence

Wave Florence

Florence time/position diagrammean propagation speed 0.90 ms-1

Florence’s speed projected backward in time

We project the measured locations of the wave backward in space/time using the wave speed determined from the slope of the wave’s x-t plot to get an idea of what/where the wave was before it was clearly a wave. The result is the pre-wave state indicated several slides previous to this. This is helping us to decide what to look for in the generation region.

pre-wave state

Wave Florence

Summary Topics of Interest

• wave pressure signature – submitted (Moum/Nash)

• shoaling / sign change – in prep. (Shroyer/Moum/Nash)

• physical structure – interfacial jets?

• energetics: evolution / transport / dissipation

• generation: bore / wave transition

• varicose waves

• wave-wave / group-group interactions