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Preliminary validation results of the prognostic 3d-TKE-scheme. Gerd Vogel, Ursula Schubert. DWD Potsdam. Zurich, September 2005. FE 14. Lindenberg. Outlook. Operational LM-prediction. May 30, 2004. Op. scheme (3tls). 3d pTKE-scheme. May 30, 2004. Gassmann, A.:.
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Preliminary validation results of the prognostic 3d-TKE-scheme Gerd Vogel, Ursula Schubert DWD Potsdam Zurich, September 2005 FE 14
Lindenberg Outlook Operational LM-prediction May 30, 2004
Op. scheme (3tls) 3d pTKE-scheme May 30, 2004 Gassmann, A.: Meteorol.and Atm. Physics, 2005, 88, 23-38 Mellor&Yamada (3tls) Mellor&Yamada (2tls) Mellor&Yamada (2tls, ALM) Outlook
Data of vertical sounding systems available from MO Lindenberg (DWD) Operational radiosonde ascents (temperature, humidity, wind components, every 6 hours, up to 25 km) LIDAR-measurements (water vapour, all 10 min between 500m - 2000m, provided by MPI Hamburg only during field experiments) Microwave profiler data (temperature , all 10 min, up to 25 km) Windprofiler-, RASS-, SODAR-systems (wind components , virtual temperature, all 10 min, 200m-3000m)
Outlook Average over 8 days (weak winds only) in May and June 2004 (Lindenberg)
Outlook Average over 8 days (weak winds only) during May and June 2004 (Lindenberg)
Microwave data Prognostic 3d-TKE scheme Comparisons with operational cross-sections based on LME-predictions daily available: http://www.dwd.de/de/FundE/Observator/MOL/mol1/passiv/mol1_pasf_e.htm
aspect ratio [Dunst (1980)] Basic features of the prognostic 3d-TKE scheme (momentum) specified flux components: (heat) simplified anisotropic diffusion approach Prandtl-Kolmogorov- specification of vertical diffusion
Vertical velocity (12 UTC) 400 m LMK 3d pTKE LMK 1d pTKE Outlook
LMK 3d pTKE LMK 1d pTKE Vertical velocity (12 UTC) Outlook
Zonal height-cross section (j=175) Vertical velocity 12 UTC LMK 3d pTKE LMK 1d pTKE
Conclusions • A proper accuracy check of the turbulence parameterisations used in the LM will only be possible if the model forcing from the surface has been improved. It’s intended to replace soil moisture, precipitation and radiation balance values at surface by measure- ments (or simulated data basing on them like soil moisture) in the whole LMK area. • Versatile vertical soundings available from Lindenberg (DWD) enable us to study thoroughly the changing boundary layer structures during the day. Based on them the model behaviour can be evaluated more comprehensively due to continuous compa- risons between measured and simulated meteorological quantities along the vertical. The implementation of the horizontal heat and momentum fluxes improves the phy-sical content of the scheme. In order to find out how accurately the present prognostic 3d-TKE scheme describes the reality (e.g. simulation of convection rolls), further validation studies are necessary, also including satellite data which often reveal such convection rolls in nature, too.