Evidence of strong sediment transport and deposition phenomena taking place during the coastal shallow water and runup stages of tsunami propagation has been reported by multiple post-event field surveys. These transport processes are expected to result in substantial alterations to the shallow water bathymetry and coastal topography, which will in turn, result in a non-linear, feedback interaction with tsunami dynamics. Tidal dynamics during tsunami events are also believed to have a substantial influence on both tsunami inundation and sediment transport. Capturing the effects of this three-way feedback loop (tsunami+sediment transport+tidal dynamics) in tsunami modeling studies requires the simultaneous solution of two coupled systems of partial differential equations, for the hydrodynamics and for sediment transport physics, and the inclusion of the added effect of tidal currents and elevations from a tidal prediction model.
The goals of this project are 1) to incorporate sediment transport and tidal dynamics to the existing nonlinear shallow water wave numerical code in use at the NOAA Center for Tsunami Research (NCTR), for tsunami hazard assessment studies, and 2) to assess and support the potential for applying this comprehensive coastal inundation code to model coastal inundation hazards amplified by climate change, e.g. sea level rise, increased extreme weather/storminess, and increased precipitation runoff.
The postdoctoral researcher will be responsible for:
1) studying the existing literature and selecting an appropriate sediment transport mathematical model for coupling with two dimensional, hydrodynamic, depth-integrated models,
2) developing a numerical solution for the selected sediment transport system,
3) incorporating nonlinear tidal effects via modification of boundary conditions,
4) coupling both the hydrodynamic and sediment transport codes so that the dynamical interaction between the two models is captured in the solution,
5) evaluating the performance and accuracy of the final code using benchmark problems to be defined by the National Tsunami Hazard Mitigation Program (NTHMP), and
6) supporting NCTR’s collaboration with PMEL and NOAA sea level projection groups to incorporate these effects into hazard assessment projects for use across NOAA and by other Federal agencies such as the US Department of State (DoS).
The postdoctoral candidate will work with NCTR and PMEL scientists as well as external partners in the numerical implementation of the final coupled model with the operational CUDA version of NCTR’s tsunami modeling code.
If an existing sediment transport model is found to be in use by other NOAA research or operational groups, the use of this model as opposed to the development of a new one will be considered. In that case, the postdoctoral researcher will be responsible for interacting closely with the relevant research group(s), for reading their model documentation, if available, or familiarizing his/herself with the sediment transport code to the degree necessary to couple the solution with the tsunami code.
The position is based in Seattle, Washington, but a partial-remote arrangement is possible within the US. Candidates should have completed a Ph.D. in a Mathematics, Physics or Engineering related field before the end of 2022 and within the last five years. A strong background in the implementation of numerical algorithms and knowledge of the CUDA programming environment are required. Previous experience with tsunami modeling is not necessary.
References:
Castro, Manuel & Fernández-Nieto, Enrique & Ferreiro, Ana. (2008). Sediment transport models in Shallow Water equations and numerical approach by high order finite volume methods. Computers & Fluids. 37. 299-316. 10.1016/j.compfluid.2007.07.017.
https://www.sciencedirect.com/science/article/abs/pii/S0045793007001454
Tang, Hui & Weiss, Robert. (2016). GeoClaw-STRICHE: A coupled model for Sediment TRansport In Coastal Hazard Events.
https://arxiv.org/abs/1609.04791
Sediment transport; Coastal erosion; Coastal inundation modeling; Tsunamis; Natural hazards; Numerical analysis; Tides; Tidal dynamics; Hazard assessment; Natural disaster models