A5018130478- Oceanographic and Atmospheric Processes
- Climate variability and models
- Meteorological Phenomena and Simulations
- Marine and coastal ecosystems
- Atmospheric and Environmental Gas Dynamics
- Arctic and Antarctic ice dynamics
- Methane Hydrates and Related Phenomena
- Fluid Dynamics and Turbulent Flows
- Quantum Chromodynamics and Particle Interactions
- Geology and Paleoclimatology Research
- High-Energy Particle Collisions Research
- Geological Studies and Exploration
- Reservoir Engineering and Simulation Methods
- Ocean Waves and Remote Sensing
- Health Sciences Research and Education
- Ocean Acidification Effects and Responses
- Cold Atom Physics and Bose-Einstein Condensates
- Marine and environmental studies
- Computational Fluid Dynamics and Aerodynamics
- Physics of Superconductivity and Magnetism
- Nuclear Issues and Defense
- Global Energy and Sustainability Research
- Tropical and Extratropical Cyclones Research
- Advanced Numerical Methods in Computational Mathematics
- Radioactive contamination and transfer
Los Alamos National Laboratory
2011-2023
Computational Physics (United States)
2008-2017
American Geophysical Union
2013
University of Alaska Fairbanks
2013
NSF National Center for Atmospheric Research
1993-2002
University of Colorado Boulder
1990-1992
In this paper an initial analysis of 0.1° simulation the North Atlantic Ocean using a level-coordinate ocean general circulation model forced with realistic winds covering period 1985–96 is presented. Results are compared to sector global 0.28° similar surface forcing and variety satellite in situ observations. The shows substantial improvements both eddy variability time-mean previous eddy-permitting simulations resolutions range 1/2°–1/6°. resolution finer than zonal-mean first baroclinic...
The sensitivity of the Atlantic Meridional Overturning Circulation (AMOC) to high‐latitude freshwater input is one key uncertainties in climate system. Considering importance AMOC for global heat transports, and vulnerability Greenland Ice Sheet (GrIS) warming, assessing this critical change projections. Here we present a unique set computational experiments investigate adjustment enhanced melt water from GrIS under present‐day conditions. For first time, response global, strongly‐eddying...
While wind is the primary driver of oceanic general circulation, it kills ocean’s most energetic motions.
The ability to reconstruct the three‐dimensional (3D) dynamics of ocean by an effective version Surface Quasi‐Geostrophy (eSQG) is examined. Using fact that surface density plays analogous role as interior potential vorticity (PV), eSQG method consists in inverting QG PV generated sea‐surface only. We also make extra assumption temperature (SST) anomalies fully represent anomalies. This approach requires a single snapshot SST and setup two parameters: mean Brunt‐Väisälä frequency parameter...
A three‐dimensional eddy census data set was obtained from a global ocean simulation with one‐tenth degree resolution and duration of 7 years. The includes 6.7 million eddies in daily data, which comprise 152,000 tracked over their lifetimes, using minimum lifetime cutoff 28 days. Variables interest include diameter, thickness (vertical extent), maximum depth, location, rotational direction, lifetime, translational speed. Distributions these traits show predominance small, thin, short‐lived,...
We consider the problem of extracting discrete two-dimensional vortices from a turbulent flow. In our approach we use reference model describing expected physics and geometry an idealized vortex. The allows us to derive novel correlation between size vortex its strength, measured as square strain minus vorticity. For detection in real models strength parameter locate potential cores, then measure similarity ideal analytical core for different thresholds. This provides metric how well is...
A coarse-graining framework is implemented to analyze nonlinear processes, measure energy transfer rates and map out the pathways from simulated global ocean data. Traditional tools cascade turbulence theory, such as spectral flux or rely on assumption of statistical homogeneity, at least a large separation between scales motion inhomogeneity. The allows for probing fully dynamics simultaneously in scale space, not restricted by those assumptions. This paper describes how can be applied...
Abstract The new Community Climate System Model, version 4 (CCSM4), provides a powerful tool to understand and predict the earth’s climate system. Several aspects of Southern Ocean in CCSM4 are explored, including surface climatology interannual variability, simulation key water masses (Antarctic Bottom Water, Subantarctic Mode Antarctic Intermediate Water), transport structure Circumpolar Current, interbasin exchange via Agulhas Tasman leakages at Brazil–Malvinas Confluence. It is found...
Abstract The strongly eddying version of the Parallel Ocean Program (POP) is used in two 45-yr simulations to investigate response Atlantic meridional overturning circulation (AMOC) enhanced freshwater input due Greenland melting, with an integrated flux 0.5 Sverdrups (Sv; 1 Sv ≡ 106 m3 s−1). For comparison, a similar set experiments performed using noneddying POP. aim identify signature salt advection feedback configurations. this reason, surface salinity not restored these experiments....
Abstract We present analysis and visualization of flow data from a high‐resolution simulation the dynamical behavior global ocean. Of particular scientific interest are coherent vortical features called mesoscale eddies. first extract high‐vorticity using metric oceanography community Okubo‐Weiss parameter. then use new circularity criterion to differentiate eddies other non‐eddy like meanders in strong background currents. From these data, we generate visualizations showing...
Abstract In this paper the atmospheric response to an open-ocean polynya in Southern Ocean is studied by analyzing results from and oceanic synoptic-scale resolving Community Earth System Model (CESM) simulation. While coarser-resolution versions of CESM generally do not produce polynyas Ocean, they emerge disappear on interannual time scales This provides ideal opportunity study polynya’s impact overlying surrounding atmosphere. has been pursued here investigating seasonal cycle differences...
Centered‐in‐space, centered‐in‐time integration has generally been used for the advection of scalars in ocean models. An assessment is made implications centered leapfrog context two‐dimensional passive tracer within a Stommel (1948) gyre. Nonphysical ripples field grow to alarming levels purely advective integrations. Diffusive parameterizations eddy mixing moderate these ripples, but it found that Laplacian diffusion greatly reduces peak amplitude field, while biharmonic or weaker allows...
Abstract An ensemble of nine simulations for the climate twentieth century has been run using Community Climate System Model version 3 (CCSM3). Three these runs also simulate uptake chlorofluorocarbon-11 (CFC-11) into ocean protocol from Ocean Carbon Intercomparison Project (OCMIP). Comparison with observations taken between 1980 and 2000 shows that global CFC-11 is simulated very well. However, there are regional biases, used to identify where too much deep-water formation occurring in...
Abstract Using numerical simulations forced by a uniform realistic wind time series, the authors show that presence of mesoscale eddy field at midlatitudes accelerates vertical propagation wind-forced near-inertial waves (NIW) and produces emergence maximum velocity into deep ocean (around 2500 m) characterized mean amplitude 25 m day−1, dominant 2f frequency, scales as small O(30 km). These results differ from previous studies reported smaller depth larger scales. The observed in present...
Abstract We present a multiscale study examining the impact of regional exchange nuclear weapons on global climate. Our models investigate multiple phases effects usage, including growth and rise fireball, ignition spread induced firestorm, comprehensive Earth system modeling oceans, land, ice, atmosphere. This follows from scenario originally envisioned by Robock, Oman, Stenchikov, et al. (2007, https://doi.org/10.5194/acp-7-2003-2007 ), based analysis Toon...
The ocean distributions of chlorofluorocarbons (CFCs) have been measured extensively in order to determine the mechanisms, rates, and pathways associated with thermohaline deep-water formation. Model temperature, salinity, CFC-11 fields from National Center for Atmospheric Research (NCAR) global climate model are compared against observations emphasis on patterns Antarctic Bottom Water (AABW) production, properties, circulation Southern Ocean. control simulation forms deep water as observed...
The influence of numerical advection algorithm properties on variational data assimilation results are investigated. Nonlinear and linear algorithms tested in a 2D idealized scalar framework which the true solution was known. accuracy optimal solutions after positively correlated with approximations used both forward adjoint models. significantly smaller experiments linearized versions nonlinear were used. This property consequence optimization convergence to local minimum cost function....
Ocean modeling presents several unique technical challenges: there is a tremendous range of spatial scales; the kinetic energy forcing scale occurs at Rossby radius deformation (20–100 km), which often or below grid resolution; and mixing strongly anisotropic, occurring primarily along nearly horizontal isopycnal surfaces. We present analysis numerical results to show that Lagrangian-averaged Navier–Stokes alpha (LANS-α) turbulence parameterization and, lesser extent, Leray are well suited...