Meteorologisches Institut der Universitat Munchen A shallow convection case from BBC: Results from the WMO international cloud modelling workshop Nicole van Lipzig, Susanne Crewell, Wenchieh Yen Meteorologisches Institut Universitaet Muenchen

Meteorologisches Institut der Universitat Munchen 6th International Cloud Modelling Workshop Hamburg, Germany; July Shallow convection case based on BBC (BALTEX BRIDGE Campaign) Cabauw observations. The case leader is Susanne Crewell (University of München/Bonn and KNMI). 2. The Elbe flooding case. This case involves convection embedded within synoptic- scale frontal precipitation. Daniela Jacob will lead this case. 3. Wintertime orographic precipitation case from December 13/14, 2001 IMPROVE II case. It will be led by Roy Rasmussen and Greg Thompson (NCAR). 4. Convective snowband case from cold air outbreak over the Sea of Japan. This case involves ice microphysics. Masataka Murakami from Japan's Meteorological Research Institute will lead this case. 5. Cloud chemistry case. This case is being organized by Mary Barth (NCAR).

Models involved in the intercomparison - DESCAM3D (bin model linked to the 3D non-hydrostatic mesoscale model of Clark et al., 1996) dx=1km Mathieu Leporini LaMP, France - bin model linked to the 3D non-hydrostatic mesoscale model CReSS Naomi Kuba, Frontier Research Center for Global Change - Clark-Hall cloud scale model (parameterized microphysics) dx=2km Wolfram Wobrock LaMP, France - Méso-NH, dx=2.5km Jean-Pierre Charboreau, Laboratoire Aerologique, France - Xueling Guo, Institute of atmospheric physics, China - Lokal Modell, dx=3km Felix Ament, Wenchieh Yen, Nicole van Lipzig, University Bonn, MIM, Munchen, Germany - RACMO1 ECHAM4 physics, dx=18km - RACMO2 ECMWF physics, dx=18km Erik van Meijgaard, KNMI de Bilt, the Netherlands - MM5 Volker Matthias, GKSS, Germany - RCA Ulrika Willén, SMHI, Sweden

Meteorologisches Institut der Universitat Munchen All models have different domain size, resolution, number of vertical levels, boundary fields as an example model setup of Lokal Modell Model domain - 440kmx440km - dx=2.8km - dt=25s - spin-up=12 hours - length of integation=36 hours - sst prescribed - lateral boundaries: analyses from the global model (GME) of the Deutsche Wetterdienst (DWD) Felix Ament

Meteorologisches Institut der Universitat Munchen Description of the Lokal-Modell - non hydrostatic - prognostic variables: surface pressure, 3D wind field, specific humidity, liquid water, turbulent kinetic energy, (ice water, rain water) - operational configuration: dx=7km; 35 levels; dt=40s - research configurations: dx=2.8km, 1.1km; 35 levels; dt=25s, 10s

Meteorologisches Institut der Universitat Munchen Clouds in the Lokal-Modell Three classes Grid scale clouds q c >0 'all or nothing' - scheme Clouds formed at saturation  Full microphysics  Dynamics  Rain  Radiation Subgrid scale clouds when ~70% < RH < 100% A parameterisation of cloud cover and liquid water  Radiation Convective Clouds Tiedtke Mass flux scheme

Meteorologisches Institut der Universitat Munchen Example 25 August UTC Liquid water path (LWP) Vertical wind velocity ~1000m above ground NOAA 14 overpass at UTC

Meteorologisches Institut der Universitat Munchen BBC cases discussed during the WMO workshop 21 May Sept 2001 MODIS optical depth 10:01UTC10:40 UTC Marc Schröder

Meteorologisches Institut der Universitat Munchen 21 May 2002 Modis 10:01 UTC 0 UTC 24 UTC Gpm500hPa IWV Winds 850 hPa Sea level pres

Meteorologisches Institut der Universitat Munchen -- large scale initialization: 0 UTC 23 May 2003, boundary forcing every 6 h Outer domain 576 x 576 km 2 dx, dy = 6 km Inner domain: 288 x 288 km 2 dx, dy = 2 km 10UTC Modis optical depth MesoNH 12UTC LWP Clark-Hall 9:30 UTC qc (g/kg)

Meteorologisches Institut der Universitat Munchen

Meteorologisches Institut der Universitat Munchen

Meteorologisches Institut der Universitat Munchen

Meteorologisches Institut der Universitat Munchen 23 September 2001 Modis 10:40 UTC 0 UTC 24 UTC Gpm500hPa IWV Winds 850 hPa Sea level pres

Meteorologisches Institut der Universitat Munchen

Meteorologisches Institut der Universitat Munchen

Meteorologisches Institut der Universitat Munchen

Meteorologisches Institut der Universitat Munchen Conclusions MesoNH has clearly the best representation of the shallow stratocumulus case (23 Sept 2001) 21 May 2003 case is very complex and none of the models is able to correctly represent this 2-layer low-level cloud structure and timing of overpass of the clouds Lokal Modell has a very patchy structure and has a very different characterisation of the clouds than the other models Problems: All models have different setup (domain size, lateral forcing, horizontal and vertical resolution), so it is difficult to find the reason for the differences between the models