National Severe Storms Laboratory
New Concepts for Studying Land-Surface-Atmosphere (LSA) Feedback
Prof. Dr. Volker Wulfmeyer
Director of the Institute of Physics and Meteorology
University of Hohenheim
13 June 2013, 11:00 AM
National Weather Center, Room 1313
120 David L. Boren Blvd.
University of Oklahoma
An accurate representation of land-surface-atmosphere (LSA) feedback is essential for the prediction of the state of the Earth system from nowcasting to decades. Particularly challenging is the currect simulation of the energy balance closure (EBC) and of entrainment fluxes at the top of the atmospheric boundary layer. New concepts for studying surface and entrainment fluxes in complex terrain are presented, which are based on a novel combination of scanning, active remote sensing systems and ensemble-based modeling.
At the land surface, severe deficiencies of present land-surface models (LSM) in the simulation of EBC are detected. Soil hydraulic coefficients, root water uptake, and the simulation of plant dynamics need to be improved. For agricultural landscapes, this is possible by the development and application of sophisticated crop growth models.
For closing the gap between models and observations, surface fluxes must be measured in 2D, particularly in complex and heterogeneous terrain. This is hardly possible with surface in-situ flux measurements, as these are suffering from poor spatial sampling and gaps in the EBC. A new approach is presented using scanning temperature and water-vapor lidar systems for measuring 2D surface sensible and latent heat fluxes and for testing Monin-Obukhov theory.
In order to achieve a good performance of a model system with respect to LSA feedback, entrainment fluxes must be correctly simulated, too. However, only in a few boundary layer parameterizations, entrainment fluxes are explicitely estimated, otherwise these are diagnosed. We present new similarity relationships derived by Sorbjan, which have the potential to become part of future ABL parameterization schemes. These relationships permit measurements of entrainment fluxes with a simplified combination of remote sensing systems. First tests of these relationships using lidar systems are presented. Finally, a field campaign employing an optimal sensor synergy for LSA feedback studies is proposed.
For accommodations based on disability, or more details, please contact NSSL @ 325-6167. All visitors without NOAA or University of Oklahoma identification must register at the registration desk on arrival. Visitor parking is available for all University visitors. However, faculty/staff/students must have a current multi-purpose parking permit. Additional parking is available at the Lloyd Noble Center (LNC) for those individuals who do not have a parking permit. You do not need a permit to park in one of 1,200 spaces reserved for CART bus riders, although you must ride the CART shuttle to park in the reserved area. This area is on the north central side of the Lloyd Noble Center. Elsewhere at the LNC, permits are required.
The University of Oklahoma became a smoke-free / tobacco-free campus