Poster about superparameterization of clouds, convection and turbulence in the global atmospheric model OpenIFS, using DALES, a high-resolution, three-dimensional large-eddy simulation code

Chertova, Maria

Crommelin, Daan

Grönqvist, Johanna

Jansson, Fredrik

Pelupessy, Inti

Siebesma, Pier

van den Oord, Gijs

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High-resolution superparameterizationof OpenIFS with DALESFredrik Jansson, Gijs van den Oord, Inti Pelupessy, Maria Chertova, Johanna Grönqvist, Daan Crommelin, Pier Siebesma one DALES instance inside each OpenIFS column1D physicsin rest of heightconnect toDALES3D ﬂux1D physicswithin columnconvection,dynamicsconnecting to other OpenIFS columnsThe earth is covered with a gridof OpenIFS columns.OpenIFS is a global atmos-pheric model, used for weatherforecasts and climatesimulations.DALESOMUSEOpenIFScoupling in PythonOMUSEDALESDALESClouds and convection takeplace on length scales smallerthan the grid size and cannotbe explicitly resolved.To explicitly simulate clouds inan OpenIFS column, we coupleit to a local 3D atmosphericmodel: DALES.The coupling to DALES replacesparts of the 1D column physicsin OpenIFS: clouds, convection,boundary layer schemes.The global model OpenIFS andthe local DALES are written inFortran. We have connectedthem through a Pythonprogram, using the OMUSEframework to connect to theFortran code.In DALES, the grid is ﬁneenough to resolve clouds andconvection in three dimensions.the OpenIFS gridDALES box4°E 6°E52°N53°N0 100 kmSuperparameterization: W. Grabowski, An Improved Framework for Superparameterization, J. Atmos. Sci. 61, 1940 (2004) D. Randall et al, Breaking the cloud parameterization deadlock, BAMS 84, 1547 (2003).M. Khairoutdinov, D. Randall, C. DeMott, Simulations of the atmospheric general circulation using a cloud-resolving model as a superparameterization of physical processes. Journal of the Atmospheric Sciences 62(7), 2136 (2005)OMUSE: I. Pelupessy et al., The Oceanographic Multipurpose Software Environment (OMUSE v1.0), Geosci. Model Dev. 10, 3167-3187 (2017).S. Portegies Zwart, et al., Multi-physics Simulations Using a Hierarchical Interchangeable Software Interface, Computer Physics Communications 183, 456-468 (2013). DALES: T. Heus, et al., Formulation of the Dutch Atmospheric Large-Eddy Simulation (DALES) and overview of its applications, Geoscientiﬁc Model Development 3, 415 (2010).Coupler:https://github.com/CloudResolvingClimateModeling/sp-couplerF. Jansson, G. van den Oord, I. Pelupessy, J. H. Grönqvist, A. P. Siebesma, D. T. Crommelin:Selective superparameterization of clouds and convection with 3D LES models in OpenIFS (under revision)0100020003000400050006000ERA5 re-analysisRadiosonde observationDALESOpenIFS standaloneOpenIFS superparametrizedtot. humidity(g/kg air)temperature (K)liquid water(g/kg air)potentialtemperature θ(K)height (m)250 275 0 5 0 0.1285 290 295MODIS cloud top heightCloudnet baseCloudnet top0 2000 4000communicationOpenIFSDALESWall-clock time (s)40 kmresolution 200m4 kmresolution 25mOpenIFS T5112012-04-13 11:35 UTCSimulation started at 00 UTCImage from theTerra satellitewith MODISComputational requirements:21h simulation took 39h on10 nodes of the ECMWF Cray- 360 cores total.Most time is spent on DALES.Grid points with more cloudsrequire shorter time stepsand take longer to simulate.We present a superparameterization ofclouds, convection and turbulence in theglobal atmospheric model OpenIFS, usinga high-resolution, three-dimensionallarge-eddy simulation, DALES.Superparameterization can be enabled for a selected region tocontrol the computational cost, leaving the global model's regularparameterization in use on the outside. Previously, superpara-meterization has been applied uniformly over all columns in theglobal model, limiting the resolution or the local model's extent.Comparing altitude dependence of atmospheric quantities;model results and observations.The superparameterized run shows higher clouds than the ERA5 dataset and standalone OpenIFS. Cloud height observationsfrom MODIS, Cloudnet, and radiosonde match the super-parameterized clouds.Superparameterized simulation over theNetherlands. Different DALES instancesshow clearly different cloud patterns.Especially the difference between cloudsover sea and land conform well to thesatellite image.The purple background shows the liquid water path in OpenIFS, the blue squares show the liquid water path in the DALES instances. References

High-resolution superparameterization of OpenIFS with DALES

https://zenodo.org/record/2657368/files/Superparameterization%20of%20OpenIFS%20with%20DALES.pdf

High-resolution superparameterization of OpenIFS with DALES

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