A Revised Hydrology for the ECMWF Model: Verification from Field Site to Terrestrial Water Storage and Impact in the Integrated Forecast System

Abstract

The Tiled ECMWF Scheme for Surface Exchanges over Land (TESSEL) is used operationally in the Integrated Forecast System (IFS) for describing the evolution of soil, vegetation, and snow over the continents at diverse spatial resolutions. A revised land surface hydrology (H-TESSEL) is introduced in the ECMWF operational model to address shortcomings of the land surface scheme, specifically the lack of surface runoff and the choice of a global uniform soil texture. New infiltration and runoff schemes are introduced with a dependency on the soil texture and standard deviation of orography. A set of experiments in stand-alone mode is used to assess the improved prediction of soil moisture at the local scale against field site observations. Comparison with basin-scale water balance (BSWB) and Global Runoff Data Centre (GRDC) datasets indicates a consistently larger dynamical range of land water mass over large continental areas and an improved prediction of river runoff, while the effect on atmospheric fluxes is fairly small. Finally, the ECMWF data assimilation and prediction systems are used to verify the effect on surface and near-surface quantities in the atmospheric-coupled mode. A midlatitude error reduction is seen both in soil moisture and in 2-m temperature.

Mechanisms of water supply and vegetation demand govern the seasonality and magnitude of evapotranspiration in Amazonia and Cerrado

“…On the demand side, 21 of the 23 model variants simulated canopy stomatal conductance (g s ), using one of four principal schemes to solve for g s , E, and leaf-level photosynthesis (if simulated) given ambient incoming radiation, air temperature, and humidity: Jarvis-type (Jarvis, 1976) (four model variants), Leuning-type (Leuning et al, 1995) (four model variants), Ball-Woodrow-Berry-Collatz (Ball et al, 1987;Collatz et al, 1991) (11 model variants), or a constant ratio of internal to external leaf CO 2 concentration (2 model variants). Balsamo et al (2009), Best et al (2011, Clapp and Hornberger (1978), Clark et al (2011), Cox et al (1998), de Rosnay and Polcher (1998, Ducoudre et al (1993), Foley et al (1996), Gerten et al (2004), Haxeltine and Prentice (1996), Jacobs (1994), Krinner et al (2005), Medvigy et al (2009), Monteith (1995, Niu et al (2011), Oleson et al (2010, Running and Coughlan (1988), Schaefer et al (2008), Sellers et al (1996), Van den Hurk et al (2000), Verseghy (1991) and Zhan et al (2003).…”

Arctic climate change in 21st century CMIP5 simulations with EC-Earth

“…It is based on cycle 31r1 of IFS, but also includes some improvements from later cycles. The most important improvements are the convection scheme by Bechtold et al (2008), the land surface scheme H-TESSEL (Balsamo et al 2009), and a new snow scheme .…”

Dynamical prediction of Arctic sea ice modes of variability

“…The atmospheric component is the ECMWF's Integrated Forecasting System (IFS) with the standard horizontal resolution T159 and 62 vertical layers up to 5 hPa. IFS also contains the land-surface H-TESSEL model (Balsamo et al 2009). …”