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Revision of the SVAT model TERRA in the COSMO model based on the validation of TERRA standalone. J. Helmert and G. Vogel Deutscher Wetterdienst. Background. Adaption of improvements in TERRA standalone (F. Ament - ZMAW University Hamburg) into COSMO code
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Revision of the SVAT model TERRA in the COSMO model based on the validation of TERRA standalone J. Helmert and G. Vogel Deutscher Wetterdienst
Background • Adaption of improvements in TERRA standalone (F. Ament - ZMAW University Hamburg) into COSMO code • Incorporation of enhanced external parameters (min. stom. resistance, emissivity, NDVI climatology, clim. soil temperature) • Adaptions of look-up tables (ensure backward compatibility) • Impact of adaptions in TERRA on soil moisture analysis (SMA) in COSMO-EU (DWD) has to be considered
CEOP sites Lindenberg/D Bondville/USA Tongyu/China 812 mm/a 2003 375 mm/a 312 mm/a 2003 2003 snow, fully humid, hot summer (Dfa) warm temperate, fully humid, warm summer (Cfb) snow, winter dry, hot summer (Dwa)
Reference conditions for different soil types (sand, silty sand, loamy sand, sandy loam and loam) Impermeable lower hydrological boundary (“rigid lid”) Ground water as lower boundary condition Depletion of root density with depth Bare soil evaporation according to Noilhan & Planton (1989) Reduction of root depth (0.2m) Revised parameterization of infiltration allowing higher infiltration rates Moisture drainage and diffusion parameterization according to Brooks & Coorey (DWD soil types) Soil heat conductivity does not depend on soil moisture Satellite derived LAI and plant cover (climatolo- gical annual cycle) Variation of surface roughness Variation of stomatal resistance and wilting point Tested options and assumptions … and various combinations of them
„Rigid lid“ Soil moisture (27- 81cm) measurement reference run (v4.0) experimental run Routine RL GW ke_soil_hy ke_soil_hy ke_soil_hy PV CEOP Lindenberg (Falkenberg) 2003
„Root depletion with depth“ Soil moisture (27- 81cm) measurement reference run (v4.0) experimental run CEOP Lindenberg (Falkenberg) 2003
„Bare soil evaporation according to Noilhan & Planton (1989)“ Soil moisture (3 - 9cm) measurement reference run (v4.0) experimental run CEOP Lindenberg (Falkenberg) 2003
Sensible heat flux Latent heat flux Bowen ratio = CEOP Lindenberg (Falkenberg) 2003 Similar improvement also achieved in 2004 – 2006 !
Cropland site (corn) Grassland site Tongyu (China) 2003 Bondville (USA) 2003
Impact of ground water compared to rigid lid Soil moisture (3 – 9cm) 2003 2004 2005 Constant groundwater (lowbound=3) vs. Rigid lid lowbound=2 (reference) Falkenberg moreover Bare soil evaporation (Noilhan & Planton) Root depeletion with deth (rootdep=0,70m) satbased LAI +plcov 2006 2007 2008
Impact of ground water compared to rigid lid Soil moisture (9 – 27cm) 2003 2004 2005 Constant groundwater (lowbound=3) vs. Rigid lid lowbound=2 (reference) Falkenberg 2006 2007 2008 moreover Bare soil evaporation (Noilhan & Planton) Root depeletion with deth (rootdep=0,70m) satbased LAI +plcov
Impact of ground water compared to rigid lid Soil moisture (27 – 81cm) 2003 2004 2005 Constant groundwater (lowbound=3) vs. Rigid lid lowbound=2 (reference) Falkenberg 2006 2007 2008 moreover Bare soil evaporation (Noilhan & Planton) Root depeletion with deth (rootdep=0,70m) satbased LAI +plcov
Impact of ground water compared to rigid lid Bowen ratio (09-16UTC) 2003 2004 2005 Constant groundwater (lowbound=3) vs. Rigid lid lowbound=2 (reference) Falkenberg 2006 2007 2008 moreover Bare soil evaporation (Noilhan & Planton) Root depeletion with deth (rootdep=0,70m) satbased LAI +plcov
COSMO-EU Experiments – Properties and Goals • Start 2009030100: #6795 (w/o SMA,HeatCond); #7004 (SMA, HeatCond) • Incorporation of enhanced external parameters (min. stom. resistance, emissivity, NDVI climatology, clim. soil temperature) • Adaptions of look-up tables (ensure backward compatibility) • Impact of adaptions in TERRA on soil moisture analysis (SMA) in COSMO-EU (DWD) has to be considered • Bare soil evaporation after Noilhan and Platon, 1989 (BS) - former Dickinson, 1984 • Non-uniform root distribution (RD) • Ground water with upward diffusion • HeatCond: Soil moisture dependent heat conductivity (#7004)
EXP 6795 Soil moisture 2009031700 Reference Soil moisture [mmH2O] Layer 3cm-9cm Difference: Reference – Experiment [mmH2O]
EXP 6795Soil moisture 2009031700 Reference Soil moisture [mmH2O] Layer 27cm-81cm Difference: Reference – Experiment [mmH2O]
EXP 67952m-Temperature 2009031700 Reference 2m-Temperature [degC] Difference: Reference – Experiment [K]
Bias 00 UTC Runs #6795
Quality 00 UTC Runs #6795
Bias 12 UTC Runs #6795
Quality 12 UTC Runs #6795
Bias 00 UTC Runs #7004
Quality 00 UTC Runs #7004
Bias 12 UTC Runs #7004
Quality 12 UTC Runs #7004
Experiments at MeteoSchweiz Thanks to J.-M. Bettems and P. Kaufmann
Experiments Verification Domains
PS, PSML: The test versions 47c shows a similar pressure bias as the reference version, with only few stations within the alps showing a slightly larger positive bias. The standard deviation is also almost identical. For the reduced pressure, the results are even closer between the two versions. T_2M: The temperature is generally higher in 47c, leading to a more positive bias at the vast majority of the stations, and to less negative bias only at stations north and south of the Alps. The negative bias within the Alps remains or is even more pronounced at particular stations. The standard deviation is very similar for test and reference.TD_2M: The dewpoint temperature bias is switching from an overestimation (wet bias) to an underestimation (dry bias) at most inland stations. The impact on the standard deviation is neutral with only a moderate increase at few stations in the Alps.FF_10M: The wind speed is generally increased, increasing the positive wind speed bias at many sites but decreasing the negative bias in the mountains. The impact on the standard deviation is neutral.CLCT: The cloud coverage bias is similar in the test version 47c as in the reference. The impact on the standard deviation is small. TOT_PREC: The positive precipitation bias of COSMO-7 is slighly reduced at few stations in the Alps only, but very similar everywhere else and also similar for COSMO-2. The standard deviation and frequency bias are all similar. + better ~ neutral - worse
Summary & Outlook • Adaption of improvements in TERRA standalone (F. Ament - ZMAW University Hamburg) into COSMO code • Comparison and verification of experiments at DWD and MeteoSchweiz • Incorporation of enhanced external parameters (min. stom. resistance, emissivity, NDVI climatology, clim. soil temperature) • Adaptions of look-up tables (ensure backward compatibility) • Impact of adaptions in TERRA on soil moisture analysis (SMA) in COSMO-EU (DWD) has to be considered • Consideration of T_2M and TD_2M Bias – wrong effect from right reasons?