Award Abstract # 1947868
Collaborative Research: Modeling wave breaking onset and dissipation in energy-conserving models for surface waves

NSF Org: OCE
Division Of Ocean Sciences
Recipient: UNIVERSITY OF WASHINGTON
Initial Amendment Date: March 17, 2020
Latest Amendment Date: March 17, 2020
Award Number: 1947868
Award Instrument: Standard Grant
Program Manager: Baris Uz
bmuz@nsf.gov
 (703)292-4557
OCE
 Division Of Ocean Sciences
GEO
 Directorate for Geosciences
Start Date: April 1, 2020
End Date: August 31, 2023 (Estimated)
Total Intended Award Amount: $272,469.00
Total Awarded Amount to Date: $272,469.00
Funds Obligated to Date: FY 2020 = $272,469.00
History of Investigator:
  • Morteza Derakhti (Principal Investigator)
    derakhti@uw.edu
  • James Thomson (Co-Principal Investigator)
Recipient Sponsored Research Office: University of Washington
4333 BROOKLYN AVE NE
SEATTLE
WA  US  98195-1016
(206)543-4043
Sponsor Congressional District: 07
Primary Place of Performance: Applied Physics Laboratory, University of Washington
1013 NE 40th Street
Seattle
WA  US  98105-6698
Primary Place of Performance
Congressional District:
07
Unique Entity Identifier (UEI): HD1WMN6945W6
Parent UEI:
NSF Program(s): PHYSICAL OCEANOGRAPHY
Primary Program Source: 01002021DB NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s):
Program Element Code(s): 161000
Award Agency Code: 4900
Fund Agency Code: 4900
Assistance Listing Number(s): 47.050

ABSTRACT

Wave breaking is a crucial process affecting a variety of ocean and coastal science and engineering problems both offshore and in the nearshore of great societal importance. This study will develop algorithms for the detection of wave breaking initiation, breaking conditions, and energy dissipation due to wave breaking, for use in phase-resolving ocean wave propagations models. Extensive validation and sensitivity analysis will be performed against recent high-fidelity numerical simulations and laboratory and field data. The robustness of the developed formulations will also be compared with existing breaking models. In addition to developing the parametrizations, this study will quantify uncertainties associated with various parametrizations of wave breaking in operational phase-resolving wave models. The model-field data comparison during storm conditions will benefit the coastal engineering community by better identifying model skill and uncertainty during storms and extreme events. The work will improve predictions of the occurrence and severity of breaking waves in phase-resolving wave models leading to: (i) a more accurate representation of wave-forcing (on currents, sediment processes, air-sea interactions, etc.) over a range of water depths, including the inner shelf, the surf zone, and river mouths; (ii) improved design analyses and safety for coastal and ocean structures and ship design. A better prediction of breaking processes and impacts during energetic/storm events will also benefit the public through improved strategies for coastal resilience. A junior scientist at the University of Washington (UW), the lead PI, will be mentored by the more senior co-PIs, which will help him transition to a permanent appointment. The project will support a female graduate student at the University of Delaware, who will be co-advised by the PIs. Outreach will be conducted at the annual "Discovery Days" event at the University of Washington.

A new, unified, and robust closure model for parameterization of the onset and progression of wave breaking in phase-resolving, energy-conserving surface wave models is proposed, applicable to Boussinesq (commonly used in shallow water) and High-Order Spectral (HOS, commonly used in deep water) models. The proposed work is motivated by and builds on recent results obtained using high-fidelity numerical simulations, which establish that the onset and strength of breaking of an individual wave crest can be determined solely from local properties of the evolving crest as it approaches breaking in arbitrary depth. The new closure model will improve on existing methods by providing a formulation that is adaptive to individual wave crests, as opposed to being calibrated based on the general features of the wave train. Extensive validation and sensitivity analysis of the proposed breaking closure model will be performed against recent high-fidelity numerical simulations, available laboratory experiments, and recent and ongoing field observations during storm conditions. Both the latter data and its use in numerical modeling are quite novel and will establish a unique model-field data comparison procedure as it requires initialization of the phase-resolving model using a wave field reconstruction algorithm. The robustness of the proposed breaking closure model will also be compared with existing breaking models.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

PROJECT OUTCOMES REPORT

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

This project has improved the predictive accuracy of wave breaking within wave-resolving forecast models. A collaborative effort between the University of Washington, University of Delaware, and University of Rhode Island led to the development and testing of a novel and unified wave breaking closure model, informed by local properties of wave crests, that signifies a major advancement over existing methods by adapting dynamically to individual wave characteristics. This model, implemented in several open-source wave-resolving forecast models, has resulted in more accurate predictions of the timing and location of wave breaking events and the evolution of waves post-breaking, enhancing our understanding of coastal and upper ocean processes, especially in high sea states and storm conditions. These advancements have significant implications for the coastal and ocean scientific community, as well as for broader societal interests. The resultant improvements in coastal management strategies directly translate into enhanced protection for communities increasingly threatened by the severe consequences of extreme weather. The project has also contributed to the growth of next-generation coastal and ocean scientists. A doctoral student successfully earned her PhD with the support of this project and early-career researchers have received valuable mentorship. The research findings have been disseminated through conferences, a doctoral dissertation, published research, and academic coursework.


Last Modified: 02/08/2024
Modified by: Morteza Derakhti

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