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© Crown copyright Met Office Radiation Parametrisation Current development work with the UM James Manners, visit to Reading University on 19 th February 2008
© Crown copyright Met Office Areas currently being investigated/trialled Split time-stepping scheme (k-terms for the window regions called more often) Orographic correction to surface SW fluxes Simple cloud inhomogeneity schemes (scaling + partially correlated overlap) Cloud generator / McICA Adaptive schemes (find perturbations due to cloud and call radiation when needed) Treatment of gaseous absorption (Zhong / Sun), ice parametrisation (Baran), UM radiance code, Robin Hogans new solvers…
© Crown copyright Met Office Cloud Inhomogeneity Work last year involved CRM tests to identify appropriate scaling values (horiz. Inhom.) and decorrelation lengths (vert. overlap) for LW and SW radiation. This scheme is fully coded in the UM and being trialled for HadGEM3. The cloud generator of Raisanen et al, 2004 is being tested for use within a McICA scheme. Cloud with acceptable radiative properties can be generated using 2 parameters: standard deviation of condensate (horizontal), and decorrelation length of vertical overlap. Single Column Scheme: Sub-grid Scheme:
© Crown copyright Met Office Comparison of generated cloud with CRM cloud. The x-axis displays sub- grid column ordered from the left by total column cloud condensate.
© Crown copyright Met Office Cloud generator parameters suitable for Cloud-Net data over Chilbolton. One set of parameters can be used for all the cases studied over Chilbolton. CRM studies of the tropical west pacific require a larger overlap parameter.
© Crown copyright Met Office Possible adaptive schemes for the future… Speed of the radiation scheme is an issue for the desired new resolutions of the UM. A fast scheme (eg. using a very simple spectral file) calculates perturbations due to changes in cloud. When the perturbations are too large the full radiation scheme is called again. Full calculations at some grid-points, others use the results from a nearby grid-point that has the closest cloud properties. Temporal scheme: Spatial scheme:
© Crown copyright Met Office Questions and answers
© Crown copyright Met Office A New Radiative Time- stepping Scheme A short description of the time-stepping scheme test Peter Hill, 19 Feb 2008.
Robin Hogan Anthony Illingworth, Sarah Kew, Jean- Jacques Morcrette, Itumeleng Kgololo, Joe Daron, Anna Townsend Quantifying sub-grid cloud structure and.
Robin Hogan Ewan OConnor Anthony Illingworth Department of Meteorology, University of Reading UK PDFs of humidity and cloud water content from Raman lidar.
Dynamical and Microphysical Evolution of Convective Storms (DYMECS) University: Robin Hogan, Bob Plant, Thorwald Stein, Kirsty Hanley, John Nicol Met Office:
Robin Hogan Anthony Illingworth, Ewan OConnor, Jon Shonk, Julien Delanoe, Andrew Barratt University of Reading, UK And the Cloudnet team: D. Bouniol, M.
Robin Hogan (with input from Anthony Illingworth, Keith Shine, Tony Slingo and Richard Allan) Clouds and climate.
19 February The Tripleclouds scheme Jon Shonk and Robin Hogan.
© Crown copyright Met Office Towards understanding the mechanisms responsible for different cloud-climate responses in GCMs. Mark Webb, Adrian Lock (Met.
Page 1© Crown copyright 2005 Use of EPS at the Met Office Ken Mylne and Tim Legg.
Robin Hogan, Julien Delanoe Department of Meteorology, University of Reading, UK Richard Forbes European Centre for Medium Range Weather Forecasts Alejandro.
Robin Hogan Julien Delanoe University of Reading Remote sensing of ice clouds from space.
© Crown copyright Met Office Regional climate model formulation PRECIS Workshop, Reading University, 23 rd – 27 th April 2012.
Robin Hogan Julien Delanoë Nicola Pounder Chris Westbrook University of Reading Approaches for variational liquid-cloud retrievals using radar, lidar and.
Robin Hogan & Anthony Illingworth Department of Meteorology University of Reading UK Parameterizing ice cloud inhomogeneity and the overlap of inhomogeneities.
Predictable Chaotic Exhibits memory Equilibrium Towards non-equilibrium Acknowledgements LD is supported by NERC CASE award NER/S/A/2004/ Conclusions.
1 00/XXXX © Crown copyright Carol Roadnight, Peter Clark Met Office, JCMM Halliwell Representing convection in convective scale NWP models : An idealised.
Clouds and their turbulent environment Robin Hogan, Andrew Barrett, Natalie Harvey Helen Dacre, Richard Forbes (ECMWF) Department of Meteorology, University.
University of Reading 2007www.nerc-essc.ac.uk/~rpa Surface radiative fluxes: comparison of NWP/Climate models/reanalyses with.
Robin Hogan Ewan OConnor Julien Delanoe Anthony Illingworth Use of ground-based radar and lidar to evaluate model clouds.
A variational cloud retrieval scheme combining radar, lidar and radiometer observations Robin Hogan & Julien Delanoe University of Reading, UK. The CloudSat.
ESA Climate Change Initiative Climate Modelling User Group CMUG
6. Equilibrium fluctuations for time-varying forcing. Values of constant term larger than expected from RCE run correspond to fluctuations greater than.
Robin Hogan Julien Delanoe, Ewan OConnor, Anthony Illingworth, Jonathan Wilkinson University of Reading, UK Quantifying the skill of cloud forecasts from.
Sampling and monitoring the environment-I Marian Scott August 2008.
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DYMECS: Dynamical and Microphysical Evolution of Convective Storms (NERC Standard Grant) University of Reading: Robin Hogan, Bob Plant, Thorwald Stein,
Robin Hogan Department of Meteorology University of Reading Cloud and Climate Studies using the Chilbolton Observatory.
4. First look Initial analysis of contrasting timeseries (Figure 2) shows: Shorter timescales have a smaller range of mass fluxes with lower maxima and.
Numerical Weather Prediction Parametrization of diabatic processes Clouds (4) Cloud Scheme Validation Richard Forbes and Adrian Tompkins
Sampling and monitoring the environment Marian Scott Sept 2006.
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