Category: Ocean modeling

Website Mailing List

Ocean Circulation and Atlantic Decadal Variability

Decadal Variability in an MITgcm Double Drake Experiment This month we look at work by Martha Buckley, David Ferreira, Jean-Michel Campin, Ross Tulloch and John Marshall, who have been using MITgcm to explore what role ocean circulation may play in Atlantic decadal variability. Asking the question: What is the role of the ocean circulation in Atlantic decadal SST variability, Buckley and co-workers use MITgcm to analyse the behavior of thermal anomalies within the framework of an idealised GCM.


Ocean Tomography

Acoustic paths Perth to Bermuda Brian Dushaw has been looking at the MITgcm ECCO2 state-estimates with help from Dimitris Menemenlis. Brian finds that by using the hydrography from the state-estimate, together with some enhanced resolution bathymetric data in key regions, he can reconstruct acoustic paths between Perth and Bermuda that were first measured in the 1960s. Previous ray-tracing efforts to reproduce this observed pathway computationally have not succeeded ….


OCCA

Surface height anomaly from OCCAThis month we focus on work by Gael Forget and the ECCO team who have been using MITgcm to construct a new ocean atlas. By using MITgcm as a means of optimally synthesising data within the framework of a physically accurate general circulation model, OCCA (short for OCean Comprehensible Atlas) provides a singularly accurate 3-year “snap-shot” of the global ocean state for the period December 2003 to November 2006…


Anthropogenic CO2 transport in the Southern Ocean.

In and out: Driven by winds, the Southern Ocean's currents (blue globe) transport CO2 (red) northward. Credit: T. Ito et al., Nature 463 (2010)Taka Ito, Molly Woloszyn and Matt Mazloff have been studying anthropogenic CO2 transport in the Southern Ocean. Using MITgcm’s adjoint and offline capabilities, the team find a clear correlation between the pattern of carbon uptake and oceanic vertical exchange in strong support of wind-driven primary regulation of Southern Ocean ACO2 transport…


Ecological Control of Subtropical Nutrient Concentrations

Multiple-Resource Experiment. (top) Emergent biogeographical provinces, defined by most dominant species, reminiscent of Longhurst (1995)
In this article we spotlight recent work by Darwin Project team members Stephanie Dutkiewicz, Mick Follows and Jason Bragg, who have been examining the utility of resource control theory to interpret the relationships between organisms and resources in a global coupled physical-biogeochemistry-ecosystem model built around MITgcm…


Overturning Sensitivity in an Eddying Ocean Model

A snapshot relative vorticity (in colors) and pressure (relief) at 100 m depth in a simulation with realistic, though idealized, forcing. The color range spans =B15e-4 s^{-1}. The domain is a simple "notched box" ocean with vertical walls and periodic channel in the southernmost 1200 km.
Work by Christopher Wolfe and Paola Cessi at UCSD, in which they investigate the equilibrium response of an eddy-resolving version of MITgcm to variations in the external parameters of diffusivity, wind forcing and geometry, with particular attention to the meridional overturning circulation (MOC) and deep stratification…


Planet-in-a-Bottle

Figure 1. The components of the system: The laboratory observatory consists of a physical system: a rotating table on which a tank, camera and control system for illumination are mounted. The computational part consists of a measurement system for velocimetry, a numerical model (MITgcm), and an assimilation system.
Work by Sai Ravela, John Marshall, Chris Hill, Andrew Wong and Scott Stransky in which they use MITgcm to provide the virtual analogue for a fluid lab experiment in the physical laboratory. This is part of an effort to demonstrate how to achieve real-time model-data synthesis, using measurements from a roboticaly controlled automated sensor system…


Tidal Mixing Over Rough Topography

Snapshot of wave zonal velocity (ms-1) deviation from the barotropic tide in the control simulation. Work by Maxim Nikurshin and Sonya Legg at GFDL using a 2d version of MITgcm to explore radiation and dissipation of the internal tides generated through tidal mixing over rough topography…


Ocean Ecosystems

Figure 1. Illustration of the key components in the self-assembling phytoplankton community model. After some years of interaction, the fittest "types" persist and occupy distinct habitats.Work by Fanny Monteiro with Mick Follows and Stephanie Dutkiewicz at MIT who have been using the MITgcm to probe the behaviour of self-assembling phytoplankton communities within a global ocean circulation…


PRM

Figure 1. Temperature sections after 60 hours from (top left) the fully resolved model, (bottom left) the multi-scale simulation and (bottom right) the balanced model with a simple convective adjustment algorithm.Work by Jean-Michel Campin, Chris Hill, Helen Jones and John Marshall at MIT using the MITgcm to exploit a multi scale superparameterization approach to increase efficiency in modeling oceanic deep convection (ODC)…