Tuesday, 11 February 2003: 2:30 PM
Land surface hydrology comparisons between the Viterbo and Beljaars land surface scheme and observations
An important component constraining atmospheric fields in Numerical Weather
Prediction (NWP) models are the latent and sensible heat fluxes provided by
Land Surface Schemes (LSSs). Coupled to a NWP model, LSSs generally ingest
model rainfall along with a number of other near-surface fields in exchange
for water and energy fluxes. Our attention is focused on the LSS developed
by Viterbo and Beljaars (1995) (hereafter VB95). VB95 is used in operational
NWP models such as the Australian Limited Area Prediction System (LAPS) or
the European Centre for Medium-range Weather Forecasts (ECMWF) global model.
Although in operational use in Australia, VB95 has never been verified
against soil hydrology datasets from the Australian region
which are believed to be markedly different from data sets of other regions.
Soil moisture and soil temperature data have been collected at various sites
in southeast Australia and four sites on the North Island of New Zealand since
1995. To remove the NWP model error, we are testing VB95 in stand-alone mode,
forced by observed rainfall and near-surface fields collected by Automated
Weather Stations (AWS) located in close proximity to the soil hydrology sites.
Comparisons between model-predicted and observed soil moisture and soil
temperature fields and the sensitivity of VB95 to variations in soil and
vegetation parameters will be presented.
This research contributes to the Murray Darling Basin Continental Scale
Experiment (MDB CSE) within the Global Energy and Water Cycle Experiment
(GEWEX). The MDB CSE aims to explore water and energy fluxes in the Murray
Darling Basin in southeast Australia.