testbed
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A parameterization testbed is an environment where model and observational datastreams come together and can easily be inter-compared. The aim is to facilitate the parameterization evaluation and development process, by confronting models with data in a structural and informed manner. While such evaluation can give confidence in the realism of a model simulation, on the other hand the models can help to gain insight into processes as they act in nature, which are not yet fully understood. In this synergy, LES models act as virtual laboratory, Single-Column Model (SCM) simulations are used to better understand and improve parameterizations for GCMs, and GCM output is used to drive process models but also to act as background reference. A relatively new use of LES is to use its three-dimensional domain to virtually test measurement strategies a priori their deployment in the field during experiments. | A parameterization testbed is an environment where model and observational datastreams come together and can easily be inter-compared. The aim is to facilitate the parameterization evaluation and development process, by confronting models with data in a structural and informed manner. While such evaluation can give confidence in the realism of a model simulation, on the other hand the models can help to gain insight into processes as they act in nature, which are not yet fully understood. In this synergy, LES models act as virtual laboratory, Single-Column Model (SCM) simulations are used to better understand and improve parameterizations for GCMs, and GCM output is used to drive process models but also to act as background reference. A relatively new use of LES is to use its three-dimensional domain to virtually test measurement strategies a priori their deployment in the field during experiments. | ||
- | The combined use of fine-scale model output and measurements can be helpful to gain insight into the process that is to be parameterized, | + | The availability of long-term (i.e. multi-year) records of both measurements and model output |
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+ | In practice the InScAPE testbed consists of a database of model simulations, | ||
==== A brief history ==== | ==== A brief history ==== | ||
- | The InScAPE parameterization testbed is a continuation of the [[http:// | + | The InScAPE parameterization testbed is a continuation of the [[http:// |
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+ | ==== Multi-year idealized DALES ==== | ||
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+ | Downscaling of a point-sampled profile from a GCM at a site of interest. | ||
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+ | LES acts as a generator of high-frequency fine-scale variability around this larger-scale state. | ||
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+ | Periodic lateral boundaries, homogeneous prescribed advective forcing. | ||
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+ | These forcings have the shape of prescribed tendencies for the horizontal advection, and prescribed subsidence velocity for the vertical advection. As a result, the latter becomes interactive with vertical gradients as generated by the LES simulation. | ||
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+ | Forcings and boundary conditions are based exclusively on ECMWF analyses and short-range (3hr) forecasts. Automated scripts have been developed to this purpose, and can be used to generate forcings at any location in the world, as far back in time as is covered by the MARS archive of IFS output. | ||
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+ | DALES is equipped with a simplified version of the ECWMF surface and soil scheme, allowing simulation with evolving surface properties and interactive surface heat fluxes. | ||
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+ | Domain size of 12.6x12.6x5km. Interactive radiation, using ECMWF state (including clouds) above the turbulent domain. Background ozone profile. | ||
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+ | While simulations are simplified, it does make them more transparent and computationally efficient. A benefit of simplicity is the huge gain in time coverage that is allowed, allowing for multi-year simulation. Currently our database of DALES simulations covers five years of 6-month (April-September) periods from 2012 to 2016. | ||
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+ | The database of idealized DALES simulations has been used in various studies. ... | ||
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+ | Recently the Inscape group is starting to experiment with blending observations from field campaigns with model-derived forcings for LES simulations. (NARVAL, ACLOUD, PASCAL) | ||
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+ | FIXME | ||
==== ICON-LEM around supersites ==== | ==== ICON-LEM around supersites ==== |
testbed.1505491661.txt.gz · Last modified: 2017/09/15 18:07 by neggers