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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 Radiation developments Latest work on the radiation code in the Unified Model James Manners, Reading collaboration meeting.
© Crown copyright Met Office A New Radiative Time- stepping Scheme A short description of the time-stepping scheme test Peter Hill, 19 Feb 2008.
19 February The Tripleclouds scheme Jon Shonk and Robin Hogan.
Robin Hogan Ewan OConnor Anthony Illingworth Department of Meteorology, University of Reading UK PDFs of humidity and cloud water content from Raman lidar.
Quantifying sub-grid cloud structure and representing it GCMs
© Crown copyright Met Office Radiation scheme for Earth’s atmosphere …and what might not work for exoplanets James Manners 6/12/11.
Robin Hogan & Anthony Illingworth Department of Meteorology University of Reading UK Parameterizing ice cloud inhomogeneity and the overlap of inhomogeneities.
Tuesday 17 November Buffet Lunch Plenary session (overviews of work at each institute) – 1.15 Radiation work at Reading (Hogan) – 1.30.
Two adaptive radiation parameterisations Annika Schomburg 1), Victor Venema 1), Felix Ament 2), Clemens Simmer 1) 1) Department of Meteorology, University.
(A) Future of Radiation Parameterizations in CAM Bill Collins National Center for Atmospheric Research
Robin Hogan Julien Delanoe University of Reading Remote sensing of ice clouds from space.
Dynamical and Microphysical Evolution of Convective Storms (DYMECS) University: Robin Hogan, Bob Plant, Thorwald Stein, Kirsty Hanley, John Nicol Met Office:
Initial 3D isotropic fractal field An initial fractal cloud-like field can be generated by essentially performing an inverse 3D Fourier Transform on the.
Cloud feedbacks in ECHAM5: preparatory results for CMIP5 Daniel Klocke Johannes Quaas, Marco Giorgetta Max-Planck-Institut für Meteorologie KlimaCampus,
Robin Hogan (with input from Anthony Illingworth, Keith Shine, Tony Slingo and Richard Allan) Clouds and climate.
© Crown copyright Met Office Towards understanding the mechanisms responsible for different cloud-climate responses in GCMs. Mark Webb, Adrian Lock (Met.
Shortwave Radiation Options in the WRF Model
© Crown copyright Met Office Systematic Biases in Microphysics: observations and parametrization Ian Boutle, Steven Abel, Peter Hill, Cyril Morcrette QJ.
© Crown copyright Met Office Convection Permitting Modelling Humphrey Lean et al. Reading, UK Leeds April 2014.
Korea Institute of Atmospheric Prediction Systems (KIAPS) ( 재 ) 한국형수치예보모델개발사업단 Comparison of Radiation Schemes Using a Single Colum Model Joonsuk Lee Jung-Yoon.
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