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Abstract. Particle tracking is widely utilized to study transport features in a range of physical, chemical, and biological processes in oceanography. In this study, a new offline particle-tracking package, Tracker v1.1, is introduced, and its performance is evaluated in comparison to an online Eulerian dye, one online particle-tracking software package, and three offline particle-tracking software packages in a small, high-resolution model domain and a large coarser model domain. It was found that both particle and dye approaches give similar results across different model resolutions and domains when they were tracking the same water mass, as indicated by similar mean advection pathways and spatial distributions of dye and particles. The flexibility of offline particle tracking and its similarity against online dye and online particle tracking make it a useful tool to complement existing ocean circulation models. The new Tracker was shown to be a reliable particle-tracking package to complement the Regional Ocean Modeling System (ROMS) with the advantages of platform independence and speed improvements, especially in large model domains achieved by the nearest-neighbor search algorithm. Lastly, trade-offs of computational efficiency, modifiability, and ease of use that can influence the choice of which package to use are explored. The main value of the present study is that the different particle and dye tracking codes were all run on the same model output or within the model that generated the output. This allows some measure of intercomparison between the different tracking schemes, and we conclude that all choices that make each tracking package unique do not necessarily lead to very different results.
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ROMSPath v1.0: offline particle tracking for the Regional Ocean Modeling System (ROMS)
Abstract. Offline particle tracking (OPT) is a widely used tool for theanalysis of data in oceanographic research. Given the output of ahydrodynamic model, OPT can provide answers to a wide variety of researchquestions involving fluid kinematics, zooplankton transport, the dispersionof pollutants, and the fate of chemical tracers, among others. In thispaper, we introduce ROMSPath, an OPT model designed to complement theRegional Ocean Modeling System (ROMS). Based on the Lagrangian TRANSport(LTRANS) model (North et al., 2008), ROMSPath is written in Fortran90 and provides advancements in functionality and efficiency compared toLTRANS. First, ROMSPath calculates particle trajectories using the ROMSnative grid, which provides advantages in interpolation, masking, andboundary interaction while improving accuracy. Second, ROMSPath enablessimulated particles to pass between nested ROMS grids, which is anincreasingly popular scheme to simulate the ocean over multiple scales.Third, the ROMSPath vertical turbulence module enables the turbulent(diffusion) time step and advection time step to be specified separately,adding flexibility and improving computational efficiency. Lastly, ROMSPathincludes new infrastructure which enables inputting of auxiliary parameters for addedfunctionality. In particular, Stokes drift can be input and added toparticle advection. Here we describe the details of these updates andperformance improvements.
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- PAR ID:
- 10439056
- Date Published:
- Journal Name:
- Geoscientific Model Development
- Volume:
- 15
- Issue:
- 11
- ISSN:
- 1991-9603
- Page Range / eLocation ID:
- 4297 to 4311
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.5194/gmd-15-4297-2022
