Abstract:

Lagrangian tracking data using the Regional Ocean Modeling System (ROMS) model at 1km and 5km horizontal resolution to simulate the behavior of passive tracers under submesoscale circulations in the Gulf of Mexico. Lagrangian particles are then released at different depths and in different months of 2015 and 2016 to investigate the impact of submesoscale motions on the eddy vertical transport in different seasons. Results are relevant to understand how upper ocean submesoscale mixing may contribute to the vertical exchange of biological tracers such as nutrients and phytoplankton.

Suggested Citation:

Bracco, Annalisa and Guangpeng Liu. 2021. Modeling study of the submesoscale mixed layer mixing in the Gulf of Mexico. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/YGR66DPP

Purpose:

Lagrangian runs are simulated to investigate the vertical transport of passive tracers in the presence of mesoscale and submesoscale circulations and where the most evident upwelling and downwelling processes exist.

Data Parameters and Units:

The data are the Larval TRANSport Lagrangian model (LTRANS) NetCDF files and includes the following parameters: Model_time [time in seconds since 01/01/2000 00:00:00, seconds]; dob [data of birth of particles in seconds from model start, seconds]; age [the age of particles, seconds]; lon [the longitude of particles, decimal degrees E]; lat [the latitude of particles, decimal degree N]; depth [depth of particles, meters below the surface]; color [identification number for particle behavior or status, nondimensional]. File naming conventions: lt_[resolution]km_wholedomain_[year][season]_[release_type]_day[release_date].nc resolution: 1 or 5, indicating 1km or 5km resolution; year: 15 or 16, indicating particle release in the year 2015 or 2016; season: Feb, May, Aug and Nov represent particles released on January 25th, April 25th, July 24th and November 1st 2015; release_type: 5m, 20M, 50m, 100m or bmld indicate particle deployments at 5m, 20m, 50m, 100m or 20m below the local mixed layer; release_date: 1, 10, 15 and 20 represent particles are released on different days (see "season" for the first day). Variables in the netcdf files: dimension 1: 21874 particles dimension 2: tracking hours [18.8 days to 40.0 days]

Methods:

Simulations were performed using the Larval TRANSport Lagrangian model (LTRANS v.2b), which is an off-line particle-tracking model that runs with the stored predictions of a 3D hydrodynamic model, specifically the Regional Ocean Modeling System (ROMS) output. For more details, please refer to the LTRANS user’s guide (Schlag et al., 2008; North et al., 2011).

Provenance and Historical References:

North, E. W., Adams, E. E., Schlag, Z., Sherwood, C. R., He, R., Hyun, K. H., & Socolofsky, S. A. (2011). Simulating oil droplet dispersal from the Deepwater Horizon spill with a Lagrangian approach. AGU Book Series: Monitoring and Modeling the Deepwater Horizon Oil Spill: A Record Breaking Enterprise., 217–226. doi:10.1029/2011gm001102 Schlag, Z., North, E. W., & Smith, K. (2008). Larval TRANSport Lagrangian model (LTRANS) user’s guide. University of Maryland Center for Environmental Science, Horn Point Laboratory, Cambridge, MD.

Individual Files: