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© Crown copyright Met Office Cloudier Evaluating a new GCM prognostic cloud scheme using CRM data Cyril Morcrette, Reading University, 19 February 2008
© Crown copyright Met Office The need for a cloud scheme Clouds exists well before grid-box reaches 100% relative humidity. But clouds exists on scales much smaller than GCM grid boxes. Cant represent them explicitly. Need to parameterize them.
© Crown copyright Met Office Summary of moisture variables in our Cloud Scheme VariableCurrent schemePC2 q cl (Liquid Water Content) DiagnosticPrognostic q cf (Ice Water Content) Prognostic q t (Total water content) Prognosticq t =q cl +q cf C l (Liquid cloud fraction) DiagnosticPrognostic C f (Ice cloud fraction) DiagnosticPrognostic
© Crown copyright Met Office Fields from LEM simulation of TOGA-COARE (Tropical convection) Mean qcl in envMean qcf in env Liquid cloud fraction Ice cloud fraction Height (km) Time (hours) Height (km) g/kg
© Crown copyright Met Office Tendencies from the LEM fields d (qcl) / dt d (qcf) / dt d (Cl) / dt d (Cf) / dt 0.36 / hr g/kg/hr
© Crown copyright Met Office Increments from Convection Detrainment dx/dt=D(x plume -x env ) Detrainment Also consider: vertical transport by compensating subsidence evaporation following warming due to compensating subsidence. (These are small effects)
© Crown copyright Met Office Increments from Convection d (qcl) / dt d (Cl) / dt d (qcf) / dt d (Cf) / dt
© Crown copyright Met Office Microphysical effects on d(qcf)/dt Deposition Sublimation Autoconversion of ice crystals to snow Fall of ice g/kg/hr
© Crown copyright Met Office Effects on d(qcf)/dt All microphysics Advection by compensating subsidence
© Crown copyright Met Office Effects on d(Cf)/dt Fall of ice Sublimation Advection by compensating subsidence
© Crown copyright Met Office Effects on d(qcl)/dt Adiabatic warming by compensating subsidence Advection by compensating subsidence Large-scale forcing Boundary-layer processes
© Crown copyright Met Office Effects on d(Cl)/dt Adiabatic warming by compensating subsidence Boundary-layer processes Large-scale forcing Advection by compensating subsidence
© Crown copyright Met Office Parameterized tendencies d (qcl) / dt d (qcf) / dt d (Cl) / dt d (Cf) / dt
© Crown copyright Met Office Comparing Tendencies d (qcl) / dt d (qcf) / dt d (Cl) / dt d (Cf) / dt Truth from LEM Parametrization
© Crown copyright Met Office Conclusions (work in progress) General methodology seems promising. Source from convective detrainment appears to be too high. (This may be due to way detrainment is calculated from LEM data) Future work Consider using a diagnostic cloud fraction for shallow convection which doesnt have large anvils.
© Crown copyright Met Office Questions and answers
© Crown copyright Met Office Extra figures Massflux
1 Numerical Weather Prediction Parameterization of diabatic processes Convection III The ECMWF convection scheme Peter Bechtold and Christian Jakob.
Clouds and their turbulent environment Robin Hogan, Andrew Barrett, Natalie Harvey Helen Dacre, Richard Forbes (ECMWF) Department of Meteorology, University.
© Crown copyright Met Office Regional climate model formulation PRECIS Workshop, Reading University, 23 rd – 27 th April 2012.
© Crown copyright 2006Page 1 CFMIP II sensitivity experiments Mark Webb (Met Office Hadley Centre) Johannes Quaas (MPI) Tomoo Ogura (NIES) With thanks.
R. Forbes, 17 Nov 09 ECMWF Clouds and Radiation University of Reading ECMWF Cloud and Radiation Parametrization: Recent Activities Richard Forbes, Maike.
Numerical Weather Prediction Parametrization of Diabatic Processes Cloud Parametrization 2: Cloud Cover Richard Forbes and Adrian Tompkins
1 PV Generation in the Boundary Layer Robert Plant 18th February 2003 (With thanks to S. Belcher)
Cloud Resolving Models: Their development and their use in parametrization development Richard Forbes, Adrian Tompkins.
© Crown copyright Met Office Convection plans Alison Stirling.
Page 1© Crown copyright 2007 Constraining the range of climate sensitivity through the diagnosis of cloud regimes Keith Williams 1 and George Tselioudis.
© Crown copyright 2006Page 1 The Cloud Feedback Model Intercomparison Project (CFMIP) Progress and future plans Mark Webb (Hadley Centre) and CFMIP contributors.
1 Numerical Weather Prediction Parametrization of diabatic processes Convection II The parametrization of convection Peter Bechtold, Christian Jakob, David.
Numerical Weather Prediction Parametrization of Diabatic Processes Clouds (1) Cloud Microphysics Richard Forbes and Adrian Tompkins
Robin Hogan Ewan OConnor, Anthony Illingworth University of Reading, UK Clouds radar collaboration meeting 17 Nov 09 Ground based evaluation of cloud forecasts.
1 Numerical Weather Prediction Parameterization of diabatic processes Convection III The ECMWF convection scheme Christian Jakob and Peter Bechtold.
© Crown copyright Met Office Scientific background and content of new gridded products Bob Lunnon, Aviation Outcomes Manager, Met Office WAFS Workshop.
Laura Davies University of Reading Supervisors: Bob Plant, Steve Derbyshire (Met Office)
Laura Davies, University of Reading, UK. Supervisors: Bob Plant, Steve Derbyshire (Met Office)
Numerical Weather Prediction Parametrization of diabatic processes Cloud Parametrization Adrian Tompkins.
© Crown copyright Met Office Radiation Parametrisation Current development work with the UM James Manners, visit to Reading University on 19 th February.
Robin Hogan (with input from Anthony Illingworth, Keith Shine, Tony Slingo and Richard Allan) Clouds and climate.
Robin Hogan Alan Grant, Ewan OConnor, Anthony Illingworth, Guy Pearson Department of Meteorology, University of Reading Observations of boundary- layer.
1 00/XXXX © Crown copyright Carol Roadnight, Peter Clark Met Office, JCMM Halliwell Representing convection in convective scale NWP models : An idealised.
Chapter 4 Water in the Atmosphere ATMO 1300 SPRING 2010.
Robin Hogan Department of Meteorology University of Reading Cloud and Climate Studies using the Chilbolton Observatory.
Robin Hogan Julien Delanoe University of Reading Remote sensing of ice clouds from space.
DYMECS: Dynamical and Microphysical Evolution of Convective Storms (NERC Standard Grant) University of Reading: Robin Hogan, Bob Plant, Thorwald Stein,
Robin Hogan Anthony Illingworth, Ewan OConnor, Jon Shonk, Julien Delanoe, Andrew Barratt University of Reading, UK And the Cloudnet team: D. Bouniol, M.
Met Office Hadley Centre, FitzRoy Road, Exeter, Devon, EX1 3PB United Kingdom Tel: +44 (0) Fax: +44 (0)
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