The performance of FLake in the Met Office Unified Model

We present results from the coupling of FLake to the Met Office Unified Model (MetUM). The coupling and initialisation are first described, and the results of testing the coupled model in local and global model configurations are presented. These show that FLake has a small statistical impact on screen temperature, but has the potential to modify the weather in the vicinity of areas of significant inland water. Examination of FLake lake ice has revealed that the behaviour of lakes in the coupled model is unrealistic in some areas of significant sub-grid orography. Tests of various modifications to ameliorate this behaviour are presented. The results indicate which of the possible model changes best improve the annual cycle of lake ice. As FLake has been developed and tuned entirely outside the Unified Model system, these results can be interpreted as a useful objective measure of the performance of the Unified Model in terms of its near-surface characteristics.

[1]  N. Wood,et al.  The Pressure force induced by neutral, turbulent flow over hills , 1993 .

[2]  H. Paerl,et al.  Blooms Like It Hot , 2008, Science.

[3]  N. Wood,et al.  Parametrizing the effects of orography on the boundary layer: An alternative to effective roughness lengths , 2001 .

[4]  J. C. B. da Silva,et al.  Remote sensing of water quality parameters over Alqueva Reservoir in the south of Portugal , 2011 .

[5]  J. Fölster,et al.  Predicting the depth and volume of lakes from map-derived parameters , 2011 .

[6]  Jan Polcher,et al.  A Proposed Structure for Coupling Tiled Surfaces with the Planetary Boundary Layer , 2004 .

[7]  W B Lewis,et al.  Neon: the UK Met office electro-optic tactical decision aid-current and future capability , 2010, Remote Sensing.

[8]  John P. Smol,et al.  Lakes and reservoirs as sentinels, integrators, and regulators of climate change , 2009 .

[9]  P. Cox,et al.  The Joint UK Land Environment Simulator (JULES), model description – Part 2: Carbon fluxes and vegetation dynamics , 2011 .

[10]  Pedro M. A. Miranda,et al.  Deriving an effective lake depth from satellite lake surface temperature data: a feasibility study with MODIS data , 2010 .

[11]  M. J. Costa,et al.  Satellite remote sensing of water turbidity in Alqueva reservoir and implications on lake modelling , 2011 .

[12]  D. G. George,et al.  UK lake plankton and the Gulf Stream , 1995, Nature.

[13]  H. Lean,et al.  The benefits of the Met Office variable resolution NWP model for forecasting convection , 2013 .

[14]  C. Hannay,et al.  Evaluation of Near-Surface Parameters in the Two Versions of the Atmospheric Model in CESM1 using Flux Station Observations , 2013 .

[15]  Christopher J. Merchant,et al.  Surface water temperature observations of large lakes by optimal estimation , 2012 .

[16]  G. Rooney,et al.  Coupling the 1-D lake model FLake to the community land-surface model JULES , 2010 .

[17]  E. Martin,et al.  Climate data for parameterisation of lakes in Numerical Weather Prediction models , 2012 .

[18]  Ekaterina Kourzeneva.  External data for lake parameterization in Numerical Weather Prediction and climate modeling , 2010 .

[19]  Tingjun Zhang,et al.  Northern Hemisphere freezing/thawing index variations over the twentieth century , 2007 .

[20]  E. Heise,et al.  Implementation of the lake parameterisation scheme FLake into the numerical weather prediction model COSMO , 2010 .

[21]  P. Jones,et al.  Uncertainty estimates in regional and global observed temperature changes: A new data set from 1850 , 2006 .

[22]  B. Henderson-Sellers,et al.  Turbulent Penetrative Convection , 1991 .

[23]  B. Lofgren.  Simulated Effects of Idealized Laurentian Great Lakes on Regional and Large-Scale Climate* , 1997 .

[24]  A. Staniforth,et al.  A new dynamical core for the Met Office's global and regional modelling of the atmosphere , 2005 .

[25]  Limin Yang,et al.  Development of a global land cover characteristics database and IGBP DISCover from 1 km AVHRR data , 2000 .

[26]  Dmitrii Mironov,et al.  An improved lake model for climate simulations: Model structure, evaluation, and sensitivity analyses in CESM1 , 2012 .

[27]  P. Cox,et al.  The Joint UK Land Environment Simulator (JULES), model description – Part 1: Energy and water fluxes , 2011 .

[28]  A. Jones,et al.  The Land Cover Map of Great Britain: an automated classification of Landsat Thematic Mapper data , 1994 .