homeAbstracts of oral contributions to the GLASS/GABLS workshop
Last update: 13 September 2005
Eleanor Blyth
The land surface exchange model of the Unified Model of the UK MetOffice (MOSES) is being developed independent of the atmospheric model. Applications of this new community model will be presented.Dara Entekhabi
Data Assimilation in Coupled
Land-Boundary Layer SystemsDara Entekhabi (MIT), Steven Margulis (UCLA), and David Flagg (York University)
In this presentation a coupled land surface and atmospheric boundary layer is used as the framework for the assimilation of standard micrometeorological measurements. The objective of the study is to develop a methodology to utilize extensive and long records of standard one-level micrometeorological measurements to estimate turbulent sensible and latent heat flux at the land-atmosphere interface.
Bart van den Hurk
What can we learn about LSM's from ELDAS soil moisture increments?Bart van den Hurk, Janneke Ettema and Pedro Viterbo
ELDAS soil moisture increments derived with the ECMWF single column model setup have been analysed for a number of locations in Europe. Data assimilation increments were derived from atmospheric humidity and temperature measurements, in a coupled land-atmosphere modelling system where precipitation and radiation were prescribed. It is found that for many locations the increments are systematically larger than the interannual variability in a multi-year offline simulation. Also, in many cases only a small portion of the increments is used to increase evaporation. Validation with ground truth showed a mixed picture, but the changes induced by the data assimilation were generally small compared to the mean bias.
Joseph Santanello
Exploiting the role of the Convective PBL for Local Land-Atmosphere Coupling (LoCo) StudiesWhile much attention has been devoted to developing complex, offline land surface models, the diurnal evolution of convective planetary boundary layer (PBL) properties and their impacts on the land surface have been relatively unexplored. Using a combination of empirical and modeling techniques, functional relationships between land surface and bulk PBL properties have been established, including the principle controls on each and pathways for feedbacks. These feedbacks determine the degree of coupling between the PBL and land surface from equilibrium to extreme (drought or flood) conditions, and their omission has limited the past and current applicability of offline land surface models. Recently, the ability of the AIRS instrument to capture PBL structure has been evaluated, and results show potential to infer information on land surface states and constrain land surface models through assimilation, while inherently retaining the first-order effects of land-atmosphere coupling. To this end, the inclusion of offline, single column model, and fully coupled experiments using synthetic and remotely sensed profile data should be a critical component of the LoCo project. Diagnosing and quantifying these fundamental interactions will ultimately aid in closing the gap between fully explicit, and expensive, coupled models and simple land surface models that can be used more easily for implementation of new data products and physical parameterizations.