1 / 22

Bridging the Gap between idealized and realistic numerical river plume simulations

Bridging the Gap between idealized and realistic numerical river plume simulations. Robert Hetland Texas A&M University. Feedback between idealized and realistic modeling. Numerical consistency. Metrics (Depends on user requirements). Idealized modeling. Realistic modeling.

paley
Download Presentation

Bridging the Gap between idealized and realistic numerical river plume simulations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Bridging the Gap between idealized and realistic numerical river plume simulations Robert Hetland Texas A&M University

  2. Feedback between idealized and realistic modeling Numerical consistency Metrics (Depends on user requirements) Idealized modeling Realistic modeling Physical consistency

  3. Transition to operational models • What are the requirements of the model end-user? • A metric that embodies this requirement. • How do you quantify good model performance? • Skill assessment measures model’s ability to reproduce the desired metric.

  4. Metric - Fresh water flux • Broad, integrative metric for buoyancy flow as a whole. • Depends on definition of reference salinity. • Also interested in the nature of the fresh water flux (e.g., what kind of water carries the fresh water?)

  5. Model skill - ‘Synoptic skill’

  6. Anatomy of a river plume • Assume that the plume may be divided into dynamically distinct regions: • Near field where advection of momentum is important. • Far field where wind forcing and the earth’s rotation are the dominant physics.

  7. Dynamically definedplume regions - cross section

  8. Dynamically definedplume regions - cross section

  9. Plume structure - Day 8.3 (mean flow, no wind) Surface salinity Fresh water thickness

  10. Mixing and the Froude # Max. vertical salt flux Froude number

  11. Dynamically definedplume regions - cross section

  12. Plume structure Fresh water thickness Surface salinity Upwelling Upwelling Downwelling Downwelling

  13. Vertical salt flux - with wind upwelling downwelling No wind

  14. Integrated vertical salt fluxWind/no wind comparison Wind No wind

  15. Surface salinity - wind vs. none

  16. Gulf of MaineSea surface salinity Hetland & Signell

  17. Fresh water flux EMCC

  18. Fresh water flux WMCC

  19. Model skill of buoyancy driven coastal current transport

  20. Realistic model conclusions • While the model does not have high skill at point-by-point comparisons, the model is good at simulating the large ‘whole plume’ scale. • The model resolution is not high enough to resolve the estuary/near field regime, but still simulates the fresh water transport correctly. Wind forcing must reduce the sensitivity to the source

  21. Fresh water (salinity class) tmax= 0.1 m2 s-2 tmax= 0.2 m2 s-2 Qf = 1000 m3 s-1 Qf = 3000 m3 s-1

  22. Future direction • Idealized modeling: • How does wind control the plume salinity and spatial dimensions? • How do other types forcing (background flow, pulsing discharge) influence water mass modification by the wind. • Realistic modeling: • What are reasonable ranges in parameter space? • What is required to resolve the small-scale features of the plume?

More Related