A revised land hydrology in the ECMWF model: a step towards daily water flux prediction in a fully-closed water cycle

The ECMWF land surface hydrology has been revised in the last 3 years in its soil and snow hydrological components, leading to improvements in weather and seasonal predictions. It has been shown that efforts devoted to the improvement of land surface processes can lead to a more accurate representation of the global water cycle on monthly timescales. In this paper, we analyse the impact of land hydrology revisions at daily timescales on both atmospheric near-surface quantities and river discharges by coupling the ECMWF land surface model (HTESSEL) to a river routing scheme total runoff integration pathways (TRIP2). This application defines a hydro-meteorological verification for land surface models and it shows the usefulness of river discharge observations for quantitative evaluation of the global water cycle at daily timescales. The relative contributions of the soil and snow hydrology revisions on atmospheric state, in particular for temperature, and the predicted river discharge are evaluated showing a significant incremental performance with the land surface updates. Copyright. (c) 2010 John Wiley & Sons, Ltd.