Monday, January 14, 2013

GFDL Seminars - Spring 2013

Check here for updates to the schedule
  • January 16, 2013: Changes in tropical cyclone activity for the western North Pacific during the last decades, derived from a regional climate model simulation.
    Monika Barcikowska (GFDL)
    In order to derive climate statistics, long and homogeneous time series are needed. For the western North Pacific different observational data sets (best track data) of tropical cyclone activity show strong discrepancies in derived trends for the last decades. As an alternative we therefore employ an atmospheric regional model (CCLM) to derive tropical cyclone activity changes by dynamically downscaling NCEP/NCAR re-analyses for the last decades. The reconstructed intense tropical cyclone's variability shows good agreement with the observed one in best track data, both on inter-annual and decadal time scales. Changes in intense tropical cyclones are associated with large-scale patterns of thermodynamic factors, like Maximum Potential Intensity, sea surface temperature (SST). Canonical correlation analysis showed that the relationship between SST and TC activity is very similar for both: simulated and observed (BTD provided by Japan Meteorological Agency) TC data sets. Trends for the annual number of tropical cyclone days show an increase for the period 1948-2011, with a short decrease in the last decade. Intense tropical cyclones increasingly influence the subtropical latitudes in the western North Pacific. The upward trend of tropical cyclone activity in the South China Sea region is mainly due to weaker storms. Decreasing tropical cyclone activity is found in the south-eastern part of the western North Pacific. Overall, the results indicate an increase and north-westward tendencies of track patterns for the period 1948-2011, which is consistent with more recent observations.
    Time: 12:00 pm - 1:30 pm
    Location: Smagorinsky Seminar Room
  • January 17, 2013: Anthropogenic Influences on Atmospheric Water Enhance Secondary Organic Aerosol Formation
    Annemarie Carlton (Rutgers)
    Water-soluble organic gases are ubiquitous in the atmosphere at the surface and throughout the atmospheric column. The chemical potential for these water-soluble organic gases to partition to particle phase liquid water (H2Optcl) and form secondary organic aerosol (SOA) is high in the Eastern U.S., higher than for partitioning pathways whereby semi-volatile organic gases partition to dry organic matter (OM). The higher potential of the wet pathway is driven by the predominance of water-soluble gases and higher H2Optcl mass concentrations relative to particle phase OM. The spatial extent, in particular dominance in the Eastern U.S. is driven by patterns in H2Optcl. The temporal and spatial co-location of water-soluble organic gas phase compounds and particle phase liquid water may resolve a key discrepancy whereby biogenic SOA mass concentrations in the southeast (SE) U.S. are high, but low in the Amazon. In the SE U.S., anthropogenic pollution and biogenic emissions routinely mix and H2Optcl concentrations are predicted to be high, largely as a consequence of sulfur pollution. The Amazon is not impacted by anthropogenic pollution (e.g., NOx, SOx) to the same degree and H2Optcl concentrations are predicted to be low. The ability of anthropogenic pollution to increase H2Optcl is well-established and routinely included in atmospheric models, however the potential for gas phase organic species to partition to this liquid water and form SOA is not. These findings suggest the current estimate that roughly half of biogenic SOA in the eastern U.S. forms only when anthropogenic pollution is sufficient to facilitate formation is too low.
    Time: 2:00 pm - 3:15 pm
    Location: Smagorinsky Seminar Room
  • January 23, 2013: Visualizing the Ocean's Overturning with Surface 14C Measurements
    Robbie Toggweiler (GFDL)
    Visualizing the Ocean's Overturning with Surface 14C Measurements
    Time: 12:00 pm - 1:30 pm
    Location: Smagorinsky Seminar Room
  • January 30, 2013: The history of GFDL computing: a user perspective
    Ron Stouffer (GFDL)
    The history of GFDL computing: a user perspective
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • January 31, 2013: TBA
    Eugenia Kalny (University of Maryland)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • February 6, 2013: Labor capacity reduction from heat stress under climate warming
    John Dunne (GFDL)
    Labor capacity reduction from heat stress under climate warming
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • February 7, 2013: Orographic convective precipitation in the tropics: Results from the Dominica Experiment.
    Ronald Smith (Yale)
    Orographic convective precipitation in the tropics: Results from the Dominica Experiment.
    Time: 2:00 pm - 3:15 pm
    Location: Smagorinsky Seminar Room
  • February 21, 2013: TBA
    Robert Chant (Rutgers)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • March 7, 2013: TBA
    Scott Denning (Howard University)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • March 14, 2013: TBA
    Paul Durack (Lawrence Livermore National Laboratory)
    TBA
    Time: 2:00 pm - 3:15 pm
    Location: Smagorinsky Seminar Room
  • March 21, 2013: TBA
    Ray Pierrehumbert (University of Chicago)
    TBA
    Time: 2:00 pm - 3:15 pm
    Location: Smagorinsky Seminar Room
  • March 27, 2013: Diagnosis of Seasonally Dependent Predictability in Observations and CM2.5
    Xiaosong Yang (UCAR)
    Diagnosis of Seasonally Dependent Predictability in Observations and CM2.5
    Time: 12:00 pm - 1:15 pm
    Location: Smagorinsky Seminar Room
  • March 28, 2013: TBA
    Dale Durran (U of Washington, Seattle)
    TBA
    Time: 2:00 pm - 3:15 pm
    Location: Smagorinsky Seminar Room
  • April 4, 2013: TBA
    Peter Huybers (Harvard University)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • April 11, 2013: Impacts of forest ecosystems on chemistry-climate interactions.
    Nadine Unger (Yale)
    TBA
    Time: 2:00 pm - 3:15 pm
    Location: Smagorinsky Seminar Room
  • April 18, 2013: TBA
    Jerry Meehl (UCAR)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • April 25, 2013: TBA
    David Battisti (University of Washington)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • May 2, 2013: TBA
    Marika Holland (NCAR)
    TBA
    Time: 2:00 pm - 3:15 pm
    Location: Smagorinsky Seminar Room
  • May 8, 2013: Global modeling of oceanic internal tides within an eddying general circulation model
    Brian Arbic (U of M)
    Global modeling of oceanic internal tides within an eddying general circulation model
    Time: 12:00 pm - 1:00 pm
    Location: Smagorinsky Seminar Room
  • May 16, 2013: TBA
    Michael Lemonick (Climate Central)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • May 23, 2013: TBA
    Raffaele Ferrari (MIT)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room
  • May 30, 2013: TBA
    Gabriele Villarini (University of Iowa)
    TBA
    Time: 2:00 pm - 3:00 pm
    Location: Smagorinsky Seminar Room

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