GFDL - Geophysical Fluid Dynamics Laboratory

GFDL Events & Seminars

Upcoming GFDL events & seminars

Events and seminars

  • December 19, 2018: Retrieving global distribution of threshold of wind erosion from satellite data and implementing it into GFDL AM4.0/LM4.0 model
    Lunchtime Seminar Series - Bing Pu (GFDL)
    Dust emission is initiated when surface wind velocities are greater than the threshold of wind erosion. Most dust models used constant threshold values globally. Here we use satellite products to constrain the frequency of dust events and surface characteristics. By matching this frequency derived from Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue aerosol products with surface winds, we are able to retrieve a climatological monthly global distribution of wind erosion threshold (Vthreshold) over dry and non-vegetated surface. This monthly two-dimensional threshold velocity is then implemented in the Geophysical Fluid Dynamics Laboratory coupled land-atmosphere model (AM4.0/LM4.0). It is found that the climatology of dust optical depth (DOD) and total aerosol optical depth, surface PM10 dust concentrations, and seasonal cycle of DOD are better captured over the “dust belt” (i.e. North Africa and the Middle East) by simulations with the new wind erosion threshold than those with the default globally constant threshold. The most significant improvement is achieved with the frequency of dust events, which is generally ignored in model evaluation. By using monthly rather than annual mean Vthreshold, all comparisons with observation are further improved. This monthly global threshold of wind erosion can be retrieved under different resolutions to match the resolution of dust models and may improve the climatology and seasonal cycle of dust simulation as well as dust forecasting.
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • January 30, 2019: 2019 Winter Poster Expo
    2019 Winter Poster Expo
    2019 Winter Poster Expo POC: Jasmin John
    Time: 1:00 pm - 5:00 pm
    Location: Smagorinsky Seminar Room
  • February 13, 2019: Energy Pathways & Cascades in both Scale and Space: Ocean Applications
    Lunchtime Seminar Series - Hussein Aluie (University of Rochester)
    Large-scale currents and eddies pervade the ocean and play a prime role in the general circulation and climate. The coupling between scales ranging from $O(10^4)$ km down to $O(1)$ mm presents a major difficulty in understanding, modeling, and predicting oceanic circulation and mixing, where our constraints on the energy budget suffer from large uncertainties. To this end, we have developed a coarse-graining (or filtering) framework for analyzing the multi-scale dynamics on the sphere. This is made possible by ensuring that our filtering operators and spatial derivatives on the sphere commute, thereby allowing us to derive the PDEs governing any sets of scales. I will demonstrate the application of this framework to satellite altimetry data and to strongly eddying high-resolution simulations using General Circulation Models. Sponsor: Stephen Griffies
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room

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