GFDL - Geophysical Fluid Dynamics Laboratory

Skip to main content

GFDL Events

Upcoming GFDL events & seminars

Events and seminars
  • May 23, 2012: TBA
    Dr. Andreas Schiller ( The Bluelink Ocean Forecasting System CSIRO Marine and Atmospheric Research Hobart, AUS)
    TBA
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • May 23, 2012: Local Oceanic Response to Atmospheric Forcing in the Gulf Stream Region
    Xujing Jia Davis (WHOI)
    Local Oceanic Response to Atmospheric Forcing in the Gulf Stream Region
    Time: 10:00 am - 11:30 am
    Location: Smagorinsky Seminar Room
  • May 30, 2012: Air Pollution (primarily aerosols) and Climate Change: From CM2.1 to CM3
    Hiram Levy (GFDL)
    Air Pollution (primarily aerosols) and Climate Change: From CM2.1 to CM3
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • May 31, 2012: Studies of low-lying Arctic clouds: Learning fundamentals of mixed-phase cloud physics from a persistent element of polar climate
    Ann Fridlind (GISS)
    Studies of low-lying Arctic clouds: Learning fundamentals of mixed-phase cloud physics from a persistent element of polar climate
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • June 7, 2012: Downwelling in Basins Subject to Buoyancy Loss
    Claudia Cenedese (WHOI)
    Recent observational, theoretical, and modeling studies all suggest that the upper part of the downwelling limb of the thermohaline circulation is concentrated in strong currents subject to buoyancy loss near lateral boundaries. This is fundamentally different from the traditional view that downwelling takes place in regions of deep convection. Even when resolving the buoyant boundary currents, coarse resolution global circulation and climate models rely on parameterizations of poorly known turbulent mixing processes. In this study, the first direct measurements of downwelling occurring within a basin subject to buoyancy loss are obtained. Downwelling is observed near the basin's vertical wall within the buoyant boundary current flowing cyclonically around the basin. Although the entire basin is cooled, large-scale mean downwelling is absent in the basin interior. Laboratory rotating experiments are conducted to explicitly resolve the turbulent mixing due to convective plumes, the baroclinic eddies generated by the boundary current, and identify where downwelling takes place. Small vertical velocities can be measured more reliably in the laboratory than in many numerical calculations, while the measurement of these small vertical velocities is still a challenge for field experiments. Downwelling is observed near the vertical wall within a boundary layer with a thickness that scales with the baroclinic Rossby radius of deformation, consistent with the dynamical balance proposed by a previous numerical study. Hence, downwelling in the Labrador Sea and Lofoten Basin cyclonic boundary currents may be concentrated in a baroclinic Rossby radius of deformation thick boundary layer in regions with large eddy generation.
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • June 13, 2012: Nighttime oxidation of biogenic hydrocarbons
    Steve Brown (ESRL)
    Nighttime oxidation of biogenic hydrocarbons
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • June 14, 2012: Identifying Human Influences on Atmospheric Temperature: Are Results Robust to Current Uncertainties?
    Ben Santer (LLNL)
    We perform a multi-model detection and attribution ("D&A") study with changes in atmospheric temperature. The observations are satellite estimates of tropospheric and stratospheric temperature change. Climate model estimates of atmospheric temperature change were obtained from phase 5 of the Coupled Model Intercomparison Project (CMIP-5). The CMIP-5 geographical patterns of externally-forced changes in atmospheric temperature ("fingerprints") are identifiable with high statistical confidence in all currently-available observed data sets. For stratospheric temperature changes over 1979 to 2011, the similarity between the searched-for fingerprint and observations increases over time, and signal-to-noise (S/N) ratios invariably exceed 15. In the troposphere, the fingerprint strength in observations is lower, but S/N ratios are still highly significant (>3), even in a satellite data set which until recently showed relatively muted tropospheric warming. This fingerprint match between models and observations occurs because of common hemispheric-scale asymmetry in the patterns of atmospheric temperature change. Our results provide clear scientific evidence for a discernible human influence on global climate, and are robust to current uncertainties in the searched-for fingerprint, model estimates of climate noise, the observations, and choices made in the application of the D&A method.
    Time: 2:00 pm - 3:15 pm
    Location: Smagorinsky Seminar Room
  • June 20, 2012: The Coherence and Impact of Meridional Heat Transport Anomalies in the Atlantic Ocean Inferred from Observations
    Kathie Kelly (University of Washington, Applied Physics Laboratory)
    Observations of thermosteric sea level (TSL) from hydrographic data, equivalent water thickness (EWT) from satellite gravity data, as well as altimetric sea surface height (SSH) anomalies, are used to construct budgets of heat and mass for the Atlantic Ocean from 31S to 64N and to infer changes in the meridional heat transport (MHT). The time-varying budgets are forced by surface heat and freshwater flux anomalies; discrepancies between the modeled response to surface fluxes and observed mass and heat content are used to infer lateral heat and mass convergences. The "unknown control" version of a Kalman filter is employed to extract smoothed budget terms and a smooth residual in each of several regions, given reasonable estimates of model and data errors. Regional convergences are then summed to estimate meridional heat transports for 1993-2010. The analysis reveals that MHT is coherent between 31S and the separated Gulf Stream and that positive anomalies in MHT correspond to increased heat loss in the subtropical gyre. The inferred MHT reproduces a recent drop and subsequent reversal seen in the RAPID/MOCHA observations at 26.5N and shows previous large anomalies. An intensification of MHT anomalies in the South Atlantic and a correlation of MHT with the Antarctic Oscillation suggests a southern source for MHT anomalies.
    Time: 12:00 pm - 1:15 pm
    Location: Smagorinsky Seminar Room
  • June 21, 2012: TBA
    Joel Norris (UCSD)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • June 27, 2012: Impact of Resolution, Parameterization and Coupling on the representation of Tropical ISOs in GCMs at GFDL / Plus: A Weather Balloon Adventure
    Bill Stern
    Impact of resolution, parameterization and coupling on the representation of tropical intraseasonal activity in GCMs at GFDL
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • October 11, 2012: TBA
    Jennifer MacKinnon (Scripps Institution of Oceanography)
    TBA`
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room

Click here to subscribe to our RSS feed.