Extended Abstract (364K)JP4.3
Regional scale energy and water flux climatologies as derived from remote sensing inputs and a land-exchange model
John R. Mecikalski, University of Alabama, Huntsville, AL; and M. C. Anderson, J. A. Otkin, and J. M. Norman
Continental scale maps of daily surface energy fluxes are being generated using the Atmospheric Land-Exchange Inverse (ALEXI) model at the University of Wisconsin. This model relies on remote sensing data to operate, including GOES-derived surface brightness temperature changes, AVHRR-derived land cover properties, as well as synoptic weather data. Sensible, latent and ground heat flux components along with net radiation are calculated on the 5-10 km scale from these inputs. Recent efforts have validated this modelling procedure to within 10-12% of surface- or tower-based instruments. Validation results for ALEXI resolutions of 5 km compare to within 30% of ground-based sensors.
Ongoing work with the ALEXI model is to develop a 2 year climatology of land-surface energy, evaporation and soil moisture (root zone, 6 cm-1.5 m, and surface layer, 0-6 cm) estimates over the continential U.S. This climatology will extend from 1 February 2002 to 31 January 2004. As part of this ongoing climatology work, this presentation will highlight the specific details of the ALEXI system that allow us to retrieve the above quantities, as well as our efforts at validating their quality. The validation of ALEXI is being done through the analysis of data collected during the Soil Moisture Atmospheric Coupling EXperiment (SMACEX) field campaign in 2002 within the state of Iowa. Accurate tower and surface flux measurements, vegetation information and soil moisture measurements are available from SMACEX to assist in developing and testing the ALEXI scheme.
Another aspect of the ALEXI research that will be presented will be our first efforts and results of the assimilation of ALEXI soil moisture information into the Local Area Prediction System (LAPS) toward the daily creation of initialization data sets for regional numerical weather predictions. Regional model simulations of the Penn State/ NCAR MM5 and/or the Weather Research and Forecast (WRF) model, using the LAPS analyses, will be discussed and presented. The goal of this component of the work will be to assess the sensitivity of soil moisture information to regional weather forecasts of boundary layer development and convection, along with assessing the value of the ALEXI-based soil information.
Joint Poster Session 4, Land-Atmosphere Interactions Posters (Joint with the 15th Symp. on Global Change and Climate Variations and 18th Conf. on Hydrology; Hall 4AB)
Tuesday, 13 January 2004, 9:45 AM-9:45 AM, Hall 4AB
Previous paper Next paper