Presupernova Structure of Massive Stars

Issues concerning the structure and evolution of core collapse progenitor stars are discussed with an emphasis on interior evolution. We describe a program designed to investigate the transport and mixing processes associated with stellar turbulence, arguably the greatest source of uncertainty in progenitor structure, besides mass loss, at the time of core collapse. An effort to use precision observations of stellar parameters to constrain theoretical modeling is also described.Comment: Proceedings for invited talk at High Energy Density Laboratory Astrophysics conference, Caltech, March 2010. Special issue of Astrophysics and Space Science, submitted for peer review: 7 pages, 3 figure

Lagrangian predictabilty of high-resolution regional ocean models

Nonlinear Processes in Geophysics, European Geosciences Union/American Geophysical Union, 11, 47-66

Turbulence variability in the upper layers of the Southern Adriatic Sea under a variety of atmospheric forcing conditions

As part of the DART06B observational campaign in late August 2006, a microstructure profiler was deployed to make turbulence measurements in the upper layers of the Southern Adriatic Sea. Of the nearly 300 total casts, 163 were made near Station B90, where various moorings were deployed in the 90 m deep water column to measure water column properties and meteorological and surface wave conditions. We were able to measure turbulence properties in the upper layers under a variety of atmospheric forcing conditions that included strong wind forcing, night-time convection, mixed convection and wind forcing, weak wind forcing and strong insolation. The resulting dataset provides a kaleidoscope of turbulence properties and turbulent mixing above, below and in the strong pycnocline present at a depth of 15 to 25 m in the coastal waters of the Southern Adriatic Sea during late summer. A slightly modified scaling of the dissipation rate of turbulence kinetic energy in the mixed layer (ML), based on the observed friction velocity u* and the surface buoyancy flux Jb0, reproduces the measured values reasonably well. In the interior, below the ML, the dissipation rate scales like , where LT is the Thorpe scale and N is the buoyancy frequency. Analysis of velocity and density profile measurements from Station B90 and the nearby station B75 suggest that anticyclonic eddies and near-inertial waves can interact in these coastal waters to produce significant horizontal advective density fluxes in the pycnocline.Published39-564A. Clima e OceaniJCR Journalope

Turbulence variability in the upper layers of the Southern Adriatic Sea under a variety of atmospheric forcing conditions

As part of the DART06B observational campaign in late August 2006, a microstructure profiler was deployed to make turbulence measurements in the upper layers of the Southern Adriatic Sea. Of the nearly 300 total casts, 163 were made near Station B90, where various moorings were deployed in the 90 m deep water column to measure water column properties and meteorological and surface wave conditions. We were able to measure turbulence properties in the upper layers under a variety of atmospheric forcing conditions that included strong wind forcing, night-time convection, mixed convection and wind forcing, weak wind forcing and strong insolation. The resulting dataset provides a kaleidoscope of turbulence properties and turbulent mixing above, below and in the strong pycnocline present at a depth of 15 to 25 m in the coastal waters of the Southern Adriatic Sea during late summer. A slightly modified scaling of the dissipation rate of turbulence kinetic energy in the mixed layer (ML), based on the observed friction velocity u* and the surface buoyancy flux Jb0, reproduces the measured values reasonably well. In the interior, below the ML, the dissipation rate scales like , where LT is the Thorpe scale and N is the buoyancy frequency. Analysis of velocity and density profile measurements from Station B90 and the nearby station B75 suggest that anticyclonic eddies and near-inertial waves can interact in these coastal waters to produce significant horizontal advective density fluxes in the pycnocline

CFD application to oceanic mixed layer sampling with Lagrangian platforms

Frontal adjustment and restratification in oceanic mixed layers is one of the processes that is considered to be important in the ocean's multi-scale energy transfer, biogeochemical transport, air-sea interaction, acoustic propagation and naval operations. We summarise a CFD-based modelling approach to sample processes at an idealised mixed layer base using passive scalars and particles, given a subset of realistic constraints on these resources in field experiments. The results emphasise the effectiveness of Lagrangian platforms, in particular passive particles, for sampling rapidly evolving submesoscale oceanic fields

A real time Nowcast/Forecast experiment in the Ligurian sea during GOATS/MEANS 2000: preliminary results

Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal