C. Kottmeier, C. Hauck, G. Schädler, N. Kalthoff Multi-scale Analysis of the Impact of Soil Moisture on Convective Precipitation C. Kottmeier, C. Hauck, G. Schädler, N. Kalthoff Institute for Meteorology and Climate Research, University of Karlsruhe Renewal proposal KO 924/9-2 precipitation for modified SM 1. unique soil moisture network 2. analysis of high-resolution data sets from the COPS-IOPs 3. GME/COSMO-DE modelling: influence of soil moisture variability on convective precipitation

Aims of the project General Objectives: Quantification of the effects of the variability of soil moisture, evapotranspiration and water content in the PBL on convective precipitation processes based on a combined observation/model approach observations: soil moisture, soil temperature, energy balance, atmospheric moisture content modelling: GME/COSMO-DE; special focus on SVAT formulation Identification of the temporal and spatial scales on which such variability influences convective precipitation scales: short-term (local impact of soil-atmosphere transport processes) & seasonal scale (soil moisture – precipitation feedback)

Time schedule & Work Packages Start: 01.07.2006 (PhD student Liane Krauss 01.01.2007) Soil moisture network: 01.06.2007 – min 01.06.2009; COPS Jun-Aug 2007 if confirmed by DFG: one open position for the modelling part Work Package 1: soil moisture measurement network Installation soil moisture & soil temperature station network Soil moisture measurements (will be maintained during the project) Quality control Validation & spatial interpolation on COSMO grid Work Package 2: analysis of COPS-IOP’s Selection of case studies, data compilation Moisture transport in the PBL and energy exchange processes Comparison with modelled data sets

Work Packages & Cooperation Work Package 3: GME/COSMO modelling Compilation of soil data SVAT model analysis High-resolution analysis of COSMO soil moisture representation Analysis of model deficiencies Determination and quantification of QPF improvement Cooperation: Surface fluxes and valley convection (Foken, Wirth, Kalthoff) Contribution of lower and upper tropospheric forcing to the initiation and inhibition of convection over complex terrain (Barthlott, Kalthoff) Bundle of proposals to exploit the data of the Convective and Orographically Induced Precipitation Study (COPS)

Installation of soil moisture network at least 2007 – 2009 installed at existing DWD/LUBW stations

Soil moisture measurements preliminary calibration Stations of the soil moisture monitoring network number of stations operating period COPS specific sites COPS Supersites with energy balance station and IMK soil moisture station 3 01.06.07 – 31.08.07 01.06.07 – 01.06.08 COPS Supersites with energy balance station and soil moisture station run by collaborating institutes 2 variable IMK energy balance station with IMK soil moisture station 7 energy balance station and soil moisture stations run by collaborating institutes 4 COPS independent stations IMK soil moisture stations 41 01.06.07 - soil moisture stations run by collaborating institutes TOTAL 60 [Krauss, Barthlott et al. submitted to Meteorol. Zeitschr.]

Soil moisture measurements Waghäusel (N) Simonswald (S) July 2007 [Krauss et al. submitted]

Comparison with GME values

obs – sim (COSMO-DE) at 5 cm depth COSMO-DE case studies COPS IOP 8b 15.07.07 obs – sim (COSMO-DE) at 5 cm depth [Krauss et al. submitted]

Outlook: observations during COPS COPS IOP 11 higher latent heat flux and lower sensible heat flux at Baden Airpark due to the larger amount of vegetation and larger evaporation from the soil soil moisture at 5 cm depth at Baden Airpark decreased by almost 3 Vol% between 9 am and 5 pm while soil moisture at Hornisgrinde remains unchanged

Outlook Site specific calibration of sensors Spatial interpolation/upscaling approaches COPS-IOP analyses COSMO-DE simulations with modified soil moisture fields Model simulations with modified soil moisture fields  changes in convective precipitation -50% +25% +50% -25%