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GFDL Events & Seminars

Upcoming GFDL events & seminars

Events and seminars
  • December 3, 2014: MJO and tropical cyclone prediction in the GFDL coupled climate model
    Baoqiang Xiang (GFDL/UCAR)
    MJO and tropical cyclone prediction in the GFDL coupled climate model
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • December 4, 2014: Multi-scale modeling of ecosystem structure and function
    Gabriel Katul (Duke U.)
    ABSTRACT: The dynamics of biological systems, from cells to communities and ecosystems, have been hypothesized to follow optimal trajectories shaped by selection pressure that force organisms to maximize their fitness and reproductive success. This concept has been particularly successful in explaining the form and function of terrestrial vegetation from an eco-hydrological and carbon-economy perspective, and across spatial and temporal scales. Any optimality model is based on three key ingredients: an objective function that describes the gain that needs to be maximized or loss to be minimized, a control variable that shifts the dynamics in the desired direction, and a set of constraints that account for environmental conditions and conservation laws bounding the system. All three ingredients are difficult to define and quantify – especially in complex biological and ecological systems. Despite these difficulties, optimality approaches may complement process-based approaches when mechanistic knowledge is scarce. At the leaf scale, it is often hypothesized that carbon gain is maximized, thus providing a quantifiable objective for a mathematical definition of optimality conditions. Eco-physiological trade-offs and fluctuating resource availability introduce natural bounds to this optimization process. In particular, carbon uptake from the atmosphere is inherently linked to water losses from the soil as water is taken up by roots and evaporated. Hence, fluctuating soil moisture constrains the amount of carbon that can be taken up and assimilated into new biomass. The problem of maximizing photosynthesis at a given water availability by modifying stomatal conductance, the plant-controlled variable to be optimized, has been traditionally formulated for short time intervals over which soil moisture changes can be neglected. This simplification led to a mathematically open solution, where the undefined Lagrange multiplier of the optimization (equivalent to the marginal water use efficiency) is heuristically determined via data fitting. Here, a set of models based on different assumptions that account for soil moisture dynamics over an individual dry-down are proposed so as to provide closed analytical expressions for the carbon gain maximization problem for varying soil moisture resources, atmospheric CO2 levels, and vapor pressure deficit. Bridging these theories with widely used empirical formulations of stomatal conductance is discussed. The newly proposed theories establish a blue print on how to link plant-water use strategies with optimality arguments at the leaf-scale. Upscaling these theories to tree and landscapes using soil- plant hydraulics are also presented.
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • December 10, 2014: The Seasonality of the Great Plains Low-Level Jet and ENSO Relationship
    Lakshmi Krishnamurthy (UCAR/GFDL)
    The Seasonality of the Great Plains Low-Level Jet and ENSO Relationship
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • December 11, 2014: Enhancement of precipitation extremes over the Southeastern US
    Wenhong Li (Duke University)
    Enhancement of precipitation extremes over the Southeastern US
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • January 14, 2015: TBA
    Griffies Guest (TBA)
    TBA
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • January 22, 2015: TBA
    Anne Thompson (NASA/GSFC)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • January 28, 2015: Poster Expo
    Poster Expo (GFDL)
    Posters
    Time: All Day
    Location: Smagorinsky Seminar Room
  • January 29, 2015: TBA
    Susan Lozier (Duke University)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • February 5, 2015: TBA
    Mian Chin (NASA)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • February 12, 2015: TBA
    Jean-Francois Lamarque (UCAR)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • February 18, 2015: TBA
    Liping Zhang (AOS)
    TBA
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • February 19, 2015: TBA
    Eli Tziperman (SEAS - Harvard)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • February 26, 2015: TBA
    Janet Sprintall (U of California - San Diego)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • March 5, 2015: TBA
    Alberto Naveira-Garabat (U of Southampton, UK)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • March 11, 2015: TBA
    Dan Li (AOS)
    TBA
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • March 12, 2015: TBA
    Mat Collins (Exeter - United Kingdom)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • March 19, 2015: TBA
    Jeremy Fyke (Los Alamos Nat'l. Lab)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • March 26, 2015: TBA
    Richard Moss (PNNL, Richland, WA)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • April 9, 2015: TBA
    Joanie Kleypas (NCAR)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • April 16, 2015: TBA
    Robert Allen (UC - Riverside)
    TBA
    Time: 2:00 pm - 3:15 pm
    Location: Smagorinsky Seminar Room
  • April 23, 2015: TBA
    Tim Lenton (Exeter - UK)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • April 30, 2015: TBA
    Clara Deser (NCAR)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • May 7, 2015: TBA
    Levi Brekke (US Bureau of Reclamation)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • May 14, 2015: TBA
    Zhou Wang (U of Illinois)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • May 21, 2015: TBA
    Steve Krueger (University of Utah)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room

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