Fersch, B.

Kunstmann, H.

Wagner, S.

Yu, Z.

Yuan, F.

English

KITopen

Prof. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationKIT – University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz AssociationInternational REKLIM Conference “OUR CLIMATE – OUR FUTURE”, Berlin, 2014www.kit.eduDevelopment and application of a coupled atmospheric-hydrological model system, suitable for regional spatial and climate relevant temporal scalesSven Wagner1,2, Benjamin Fersch1, Harald Kunstmann1,2, Fei Yuan3, Zhongbo Yu3,41 Karlsruhe Institute of Technology (KIT - IMK-IFU), Germany 2 Institute of Geography, University of Augsburg, Germany3 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, China 4 Department of Geoscience, University of Nevada, Las Vegas, NV, USAInt. REKLIM Conference, Berlin, 20142 Sven WagnerObjectives All components of hydrological cycle are affected by climate and landuse changes  Joint landuse- & climate change impact analysis on regional water cycle requires  Investigations on Feedback mechanisms between the atmosphere, land surface & subsurface conditions The quantification of such feedback mechanisms calls for coupled modelling systems that consist of a - regional atmospheric- & - distributed hydrological model- sharing compatible water & energy flux formulations15.10.2014Prof. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 20143Overview Model Approach 15.10.2014WRF HMS Both models use the same land surface model (Noah-LSM) Both models communicate at the same scale  Allows long-term simulations at regional spatial and climate relevant temporal scalesSven WagnerLSMInt. REKLIM Conference, Berlin, 20144WRF-HMS – Coupling strategy & Application15.10.2014WRF HMS Implementation of HMS model in the WRF code structure (hydrology driver routine) allowing flexible time step application Serial HMS code was adapted to support MPI parallel execution HPC capacity of coupled modelling system  Prerequisite for long-term simulations !!!Sven WagnerLSMStep1: WRF setupStep3: Fully coupled WRF-HMSStep2: HMS setupProf. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 20145Research area: Poyang Lake Basin, China Basin size: 160 000 km² (lake up to 4000 km²) Tributary of Yangtze River  Humid subtropical climate: - mean annual temperature: 17.6°C- mean annual precipitation: 1500 mmSource: NASADEM: Soil map:LU map: River network:Source: NASA15.10.2014 Sven WagnerInt. REKLIM Conference, Berlin, 20146Step1: WRF setup Double nesting approach: D01 (30km), D02(10km) Several configurations of WRF with respect tomodel physics and vertical resolution Reanalysis simulations to find appropriate setupusing ERA interim (2003-2005) Validation data: CRU3, GPCC, APHRODITE15.10.2014 Sven WagnerWagner et al (2013) Temperature [°C] Precipitation [mm]- MP: WSM5- Radiation: RRTM- PBL: Yonsei Univ. - Cumulus: Betts-Miller-Janjic Prof. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 20147Step2: NOAH-LSM – HMS simulationsSven Wagner15.10.2014 Meteorological forcing: interpolated station data   use implemented HMS model in the WRF code- same modules & input data (except met. forcing)    Int. REKLIM Conference, Berlin, 20148Step 2: NoahLSM-HMS – PREPROCESSING:Additional hydrological input parameters15.10.2014DEM (sd):USGS  HYDRO1K (GTOPO30)Aquifer thickness:Chinese Geological data setHydraulic conductivity:Chinese Geological data setStreambed depth:USGS  HYDRO1K Sven WagnerProf. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 20149Step2: NOAH-LSM – HMS simulations Simulation results for 1978 - 1986:ET [mm]: RUNOFF [mm]:DISCHARGE [m³/s]:Sven WagnerRAIN [mm]: HEAD [mm]:Waizhou15.10.201420001500100010005000100050005002500Int. REKLIM Conference, Berlin, 201410Step2: NOAH-LSM – HMS simulations VALIDATION: simulated discharge [m3/s] @ Waizhou for 1978 – 1986:15.10.2014 Sven WagnerProf. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 201411Step2: NOAH-LSM – HMS with GW-feedback Methods for allowing feedbacks between LSM and saturated zone Coupling of saturated to unsaturated zone Two way interaction & fluxes (e.g. capillary rise vs. gravity fluxes)   between saturated and unsaturated zone Richard‘s equation with fixed-head boundary condition  based on Zeng et al. (2009), De Rooij (2010) Darcy flux boundary condition based on Bogaart et al. (2008)15.10.2014LSMSven WagnerInt. REKLIM Conference, Berlin, 201412Step2: NOAH-LSM – HMS with GW-feedback Sven Wagner15.10.2014Soil moisture 0–10 cm Impact of feedback between LSM and saturated zone on simulation results Difference plots “Fixed head” versus “no Coupling”  Evapotranspiration [%]Recharge [%] Difference plots “Darcy-Flux” versus “no Coupling”  0.0250-0.025500-10100-10501000-50-500.025-0.0250Prof. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 201413Step3: WRF – NOAH-LSM – HMS simulationsSven Wagner15.10.2014 Use the identified optimal stand-alone WRF  and HMS setup Allows investigations of hydrological land surface – atmosphere feedbackInt. REKLIM Conference, Berlin, 201414 Sven Wagner15.10.2014Step3: WRF – NOAH-LSM – HMS simulationsFully coupled simulation results with GW feedback  Difference plots “Fixed head” versus “no Coupling”  Soil moisture 0–10 cm Evapotranspiration [%]Recharge [%]0.025-0.02500-10101000-100Prof. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 201415 Sven Wagner15.10.2014Step3: WRF – NOAH-LSM – HMS simulationsFully coupled simulation results with GW feedback  Difference plots“Fixed head” versus “no Coupling”  Soil moisture 0–10 cm 1m2m0mno Coupling1m2m0mFixed headValidation:0.025-0.0250Int. REKLIM Conference, Berlin, 201416 Sven Wagner15.10.2014Step3: WRF – NOAH-LSM – HMS simulationsFully coupled simulation results with GW feedback  Difference plots “Fixed head” versus “no Coupling”  Soil moisture 0–10 cm Evapotranspiration [%]Recharge [%]0.025-0.02500-10101000-1000Precipitation [%]100-10Temperature [°C]0.15Prof. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 201417SummaryObjective:  Investigations on Feedback mechanisms between the atmosphere, land surface & subsurface conditionsFully coupled modelling system: Integration of HMS preprocessors & code in WRF model structure  Integration of GW feedback mechanisms in coupled model systemPoyang Lake Basin:  Performance & potential of fully coupled simulations incl. GW-feedback GW-feedback impact conditions in LSM, land surface & lower atmosphere This work is financially supported by the German Research Foundation (DFG) and National Natural Science Foundation of China (NSFC) 15.10.2014Thank you for your attentionSven WagnerInt. REKLIM Conference, Berlin, 201418 Sven Wagner15.10.2014Prof. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 201419Model Components: WRF & Noah-LSM “Lower boundary of WRF” ∆t ≈ tens of minutes 4 soil layers Vertical water and energy fluxes Important for feedbacks between near surface soil, boundary layer & atmosphere Non-hydrostatic, ∆x≈1km-50km, ∆t ≈ tens of seconds Based on conservation laws Subgridscale processes: parameterized Nested approach: lateral boundary from GCM15.10.2014 Sven WagnerInt. REKLIM Conference, Berlin, 201420 Spatially distributed  Suitable for large- scale applications , ∆x≈ up to a few tens of km: 10 km here streamflow routing - 2D diffusive wave, ∆t ≈ tens of minutes Interaction of  channel & vadose zone or channel & groundwater flux Unsaturated soil moisture profile is assumed to be in equlibrium 2D horizontal groundwater flow: one layer aquifer, simple bedrock,  ∆t ≈ 1 dayModel Components: HMS  (Yu et al, 2006)15.10.2014 Sven WagnerProf. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 201421Step2: NOAH-LSM – HMS simulationsSven Wagner15.10.2014 Meteorological forcing: interpolated station data   use implemented HMS model in the WRF code- same modules & input data (except met. forcing)  Calibration of HMS:- Noah LSM parameters: FXEXP, REFKDT, …- HMS parameters: Manning, conductivities, …Int. REKLIM Conference, Berlin, 201422Feedback between LSM and saturated zoneApproach 1: Richard‘s equation with fixed-head boundary condition Based on Zeng et al. (2009), De Rooij (2010)LSM Free drainage boundary condition ofLSM is replaced by a fixed-head bottomboundary condition which assumes anequilibrium soil moisture distribution Hydraulic head & soil moisture at the lowerboundary of LSM is derived from distancebetween groundwater level and bottomof LSM conserving the energy and massof water New boundary condition realized withadditional layer at bottom of Noah-LSM Label: Fixed-Head15.10.2014 Sven WagnerDistinction of 3 cases:  new layer is un-, partially- or fully saturated, e.g.  Prof. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 201423Feedback between LSM and saturated zoneApproach 2: Darcy flux boundary conditionBased on Bogaart et al. (2008)• Assumes a quasi steady-state moistureprofile between groundwater head andlowest soil layer of the LSM.• Darcy equation is used to describe flowthrough this transition zone depending onrelative saturation at bottom of LSM• Parameterization that approximates netDarcy flux qdarcy for different thicknesses oftransition zone and different values ofsaturation for lowest LSM soil layer• Label: Darcy-FluxLSMqdarcy= ?15.10.2014 Sven WagnerInt. REKLIM Conference, Berlin, 201424 Sven Wagner15.10.2014Step3: WRF – NOAH-LSM – HMS simulationsVALIDATION: simulated discharge [m3/s] @ Waizhou for 1978 – 1986 of fullycoupled model system“no GW-Coupling”  “Fixed-Head GW-Coupling”  Prof. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 201425 Sven Wagner15.10.2014Step3: WRF – NOAH-LSM – HMS simulationsFully coupled simulation results with GW feedback  In fully coupled mode: in addition impact on atmospheric variables e.g. Precipitation Difference plots “Fixed head” versus “no Coupling”  Precipitation [mm]100-10Int. REKLIM Conference, Berlin, 201426 Implementation of HMS model in the WRF code structure (hydrology driver routine) allowing flexible time step application Integration of preprocessors (static surface and sub-surface hydrological parameters)  NetCDF compliance (IO) Serial HMS code was adapted to support MPI parallel execution HPC capacity of coupled modelling system  Prerequisite for long-term simulations !!!WRF-NoahLSM-HMS – Coupling strategy:15.10.2014 Sven WagnerProf. Dr. Max Mustermann | MusterfakultätKIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz AssociationInt. REKLIM Conference, Berlin, 201427Application of the fully coupled modelling system15.10.2014WRF HMSStep1: WRF setupStep3: Fully coupled WRF-HMSStep2: HMS setupSven Wagner

Development and application of a coupled atmospheric-hydrological model system, suitable for regional spatial and climate relevant temporal scales

https://publikationen.bibliothek.kit.edu/230097906/3816684

Development and application of a coupled atmospheric-hydrological model system, suitable for regional spatial and climate relevant temporal scales

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