BEGIN:VCALENDAR VERSION:2.0 X-WR-CALNAME:EventsCalendar PRODID:-//hacksw/handcal//NONSGML v1.0//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:America/New_York LAST-MODIFIED:20240422T053451Z TZURL:https://www.tzurl.org/zoneinfo-outlook/America/New_York X-LIC-LOCATION:America/New_York BEGIN:DAYLIGHT TZNAME:EDT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 DTSTART:19700308T020000 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU END:DAYLIGHT BEGIN:STANDARD TZNAME:EST TZOFFSETFROM:-0400 TZOFFSETTO:-0500 DTSTART:19701101T020000 RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU END:STANDARD END:VTIMEZONE BEGIN:VEVENT CATEGORIES:College of Arts and Sciences,College of Engineering,Graduate Stu dies,Lectures and Seminars,SMAST,STEM,Thesis/Dissertations DESCRIPTION:Department of Estuarine and Ocean Sciences PhD Dissertation Def ense "Waves and Vortices in the Ocean - From Theory to Practice"By: Bailey Remy Advisor:Dr. Miles Sundermeyer (UMass Dartmouth) Committee Members:Dr . Geoffrey Cowles (UMass Dartmouth), Dr. Banafsheh Seyed-Aghazadeh (UMass Dartmouth), and Dr. Marie-Pascale Lelong (NorthWest Research Associates) M onday May 18, 202611:00 AMSMAST East 101-103836 S. Rodney French Blvd, New Bedfordand via Zoom Abstract: Internal waves (IWs) are ubiquitous in the ocean and contribute significantly to the global ocean energy balance by c ascading tidal and wind-driven energy to dissipative scales. Vortical moti ons (VMs), which exist at scales similar to IWs, carry potential vorticity (PV) and influence ocean circulation, mixing, and climate variability. Di stinguishing these motions remains a fundamental challenge, as nonlinear i nteractions in fully developed flows obscure their individual signatures. This dissertation addresses two aspects of IWs and VMs in the ocean. Chapt ers 1 and 2 investigated mechanisms of energy exchange between IWs and VMs , and the physical signatures and associated dynamics of reduced stratific ation regions in the ocean. Chapter 3 examined the use of IW and VM signat ures to detect underwater wakes in realistic ocean environments.   Chapte r 1 examined energy exchange between IWs and VMs in the ocean, focusing on the contrasting roles of linear and nonlinear flow components in shaping available potential vorticity (APV) fields. In numerical simulations initi alized with a Garrett-Munk IW spectrum, energy was rapidly projected onto the linear VM basis by nonlinear triad interactions. Idealized simulations of a single linear IW, a balanced vortex, and an adjusting density anomal y exposed limitations of the linear flow decomposition: Lagrangian particl e tracking revealed that linear APV differed from total APV due to nonline ar vortex stretching terms, causing the linear decomposition to overestima te the PV-carrying component of flow. These results suggest that apparent rapid VM generation can sometimes reflect nonlinear artifacts rather than true PV modification. Chapter 2 examined the prevalence and nature of redu ced stratification regions in the ocean relative to IW and VM dynamics. Oc cupying between ~5% and 25% of the model domain, such regions exhibited di stinct morphological and dynamical signatures consistent with linear theor y. Regions of reduced stratification that projected onto linear VMs exhibi ted aspect ratios exceeding the canonical N0/f scaling, and horizontal sc ales exceeding the local Rossby deformation radius. Regions that projected onto linear IWs more closely follow theoretical wave scaling and propagat ion characteristics. Lagrangian particle tracking and spectral shear-to-st rain ratios further distinguished propagating wave motions from materially conserved vortical motions. Additionally, the generation of VM stratifica tion anomalies was found to be energetically more consistent with prolonge d mixing events (time scales longer than a buoyancy period) than intense s hort-term mixing events. These findings confirm that reduced stratificatio n regions in the ocean can result from both internal wave straining and pe rsistent vortical motions, and that certain interactions between them are consistent with current dynamical understanding of both phenomena. Buildin g on increased understanding of the relationship between IWs and VMs in th e ocean, Chapter 3 explored the generation and evolution of IWs and VMs in the wake of a towed body, and their exploitation for the purposes of wake detection. Numerical simulations initialized using an idealized late wake approximation showed that the vortex street generated by the wake was rea dily detected via potential enstrophy even amid a strong background IW fie ld. IWs radiated during buoyant collapse of the wake were also readily det ected among varying background conditions due to their highly coherent rad iation pattern. Wake evolution depended on both nondimensional and dimensi onful parameters associated with the wake; vortex evolution time scales va ried with Froude number, while wave detectability was primarily influenced by wake diameter modulating signal intensity. Overall, these results sugg est that, when carefully considered, both IW and VM signatures of submerge d wakes can be readily detected under a wide range of conditions even amid the “noisy” background internal wave field of the ocean. Join Meeting https://umassd.zoom.us/j/95380787170Note: Meeting ID and passcode required - email contact to obtain. For additional information, please contact Call ie Rumbut at c.rumbut@umassd.edu\nEvent page: https://www.umassd.edu/event s/cms/deos-phd-dissertation-defense-waves-and-vortices-in-the-ocean---from -theory-to-practice-by-bailey-remy.php\nEvent link: https://umassd.zoom.us /j/95380787170 X-ALT-DESC;FMTTYPE=text/html:

Department of Estuarine and Oce an Sciences

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PhD Dissertation Defense

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"Waves and Vortices i n the Ocean - From Theory to Practice"
By: Bailey Remy

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Adviso r:
Dr. Miles Sundermeyer (UMass Dartmouth)

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Committee Members:
Dr. Geoffrey Cowles (UMass Dartmouth)\, Dr. Banafsheh Seyed-Aghazade h (UMass Dartmouth)\, and Dr. Marie-Pascale Lelong (NorthWest Research Ass ociates)

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Monday May 18\, 2026
11:00 AM
SMAST East 101-10 3
836 S. Rodney French Blvd\, New Bedford
and via Zoom

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A bstract:

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Internal waves (IWs) are ubiquitous in the ocean and cont ribute significantly to the global ocean energy balance by cascading tidal and wind-driven energy to dissipative scales. Vortical motions (VMs)\, wh ich exist at scales similar to IWs\, carry potential vorticity (PV) and in fluence ocean circulation\, mixing\, and climate variability. Distinguishi ng these motions remains a fundamental challenge\, as nonlinear interactio ns in fully developed flows obscure their individual signatures. This diss ertation addresses two aspects of IWs and VMs in the ocean. Chapters 1 and 2 investigated mechanisms of energy exchange between IWs and VMs\, and th e physical signatures and associated dynamics of reduced stratification re gions in the ocean. Chapter 3 examined the use of IW and VM signatures to detect underwater wakes in realistic ocean environments.

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\n< p>Chapter 1 examined energy exchange between IWs and VMs in the ocean\, fo cusing on the contrasting roles of linear and nonlinear flow components in shaping available potential vorticity (APV) fields. In numerical simulati ons initialized with a Garrett-Munk IW spectrum\, energy was rapidly proje cted onto the linear VM basis by nonlinear triad interactions. Idealized s imulations of a single linear IW\, a balanced vortex\, and an adjusting de nsity anomaly exposed limitations of the linear flow decomposition: Lagran gian particle tracking revealed that linear APV differed from total APV du e to nonlinear vortex stretching terms\, causing the linear decomposition to overestimate the PV-carrying component of flow. These results suggest t hat apparent rapid VM generation can sometimes reflect nonlinear artifacts rather than true PV modification.

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Chapter 2 examined the prevalen ce and nature of reduced stratification regions in the ocean relative to I W and VM dynamics. Occupying between ~5% and 25% of the model domain\, suc h regions exhibited distinct morphological and dynamical signatures consis tent with linear theory. Regions of reduced stratification that projected onto linear VMs exhibited aspect ratios exceeding the canonical N0/f scal ing\, and horizontal scales exceeding the local Rossby deformation radius. Regions that projected onto linear IWs more closely follow theoretical wa ve scaling and propagation characteristics. Lagrangian particle tracking a nd spectral shear-to-strain ratios further distinguished propagating wave motions from materially conserved vortical motions. Additionally\, the gen eration of VM stratification anomalies was found to be energetically more consistent with prolonged mixing events (time scales longer than a buoyanc y period) than intense short-term mixing events. These findings confirm th at reduced stratification regions in the ocean can result from both intern al wave straining and persistent vortical motions\, and that certain inter actions between them are consistent with current dynamical understanding o f both phenomena.

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Building on increased understanding of the relat ionship between IWs and VMs in the ocean\, Chapter 3 explored the generati on and evolution of IWs and VMs in the wake of a towed body\, and their ex ploitation for the purposes of wake detection. Numerical simulations initi alized using an idealized late wake approximation showed that the vortex s treet generated by the wake was readily detected via potential enstrophy e ven amid a strong background IW field. IWs radiated during buoyant collaps e of the wake were also readily detected among varying background conditio ns due to their highly coherent radiation pattern. Wake evolution depended on both nondimensional and dimensionful parameters associated with the wa ke\; vortex evolution time scales varied with Froude number\, while wave d etectability was primarily influenced by wake diameter modulating signal i ntensity. Overall\, these results suggest that\, when carefully considered \, both IW and VM signatures of submerged wakes can be readily detected un der a wide range of conditions even amid the “noisy” background intern al wave field of the ocean.

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Join Meeting
https://umassd.zoom.us/j/95380787170
N ote: Meeting ID and passcode required- email contact to obtain.

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Fo r additional information\, please contact Callie Rumbut at c.rumbut@umassd.edu

Event page: https:/ /www.umassd.edu/events/cms/deos-phd-dissertation-defense-waves-and-vortice s-in-the-ocean---from-theory-to-practice-by-bailey-remy.php
Event l ink: https://umassd.zoom.us /j/95380787170

DTSTAMP:20260424T004240 DTSTART;TZID=America/New_York:20260518T110000 DTEND;TZID=America/New_York:20260518T120000 LOCATION:SMAST East 101-103 SUMMARY;LANGUAGE=en-us:DEOS PhD Dissertation Defense: "Waves and Vortices i n the Ocean - From Theory to Practice" by Bailey Remy UID:8cb9540f5dd5fd839f5197dded36d448@www.umassd.edu END:VEVENT END:VCALENDAR