Mesoscale nesting interface of the PALM model system 6.0

Author:

Kadasch Eckhard,Sühring Matthias,Gronemeier TobiasORCID,Raasch Siegfried

Abstract

Abstract. In this paper, we present a newly developed mesoscale nesting interface for the PALM model system 6.0, which enables PALM to simulate the atmospheric boundary layer under spatially heterogeneous and non-stationary synoptic conditions. The implemented nesting interface, which is currently tailored to the mesoscale model COSMO, consists of two major parts: (i) the preprocessor INIFOR (initialization and forcing), which provides initial and time-dependent boundary conditions from mesoscale model output, and (ii) PALM's internal routines for reading the provided forcing data and superimposing synthetic turbulence to accelerate the transition to a fully developed turbulent atmospheric boundary layer. We describe in detail the conversion between the sets of prognostic variables, transformations between model coordinate systems, as well as data interpolation onto PALM's grid, which are carried out by INIFOR. Furthermore, we describe PALM's internal usage of the provided forcing data, which, besides the temporal interpolation of boundary conditions and removal of any residual divergence, includes the generation of stability-dependent synthetic turbulence at the inflow boundaries in order to accelerate the transition from the turbulence-free mesoscale solution to a resolved turbulent flow. We demonstrate and evaluate the nesting interface by means of a semi-idealized benchmark case. We carried out a large-eddy simulation (LES) of an evolving convective boundary layer on a clear-sky spring day. Besides verifying that changes in the inflow conditions enter into and successively propagate through the PALM domain, we focus our analysis on the effectiveness of the synthetic turbulence generation. By analysing various turbulence statistics, we show that the inflow in the present case is fully adjusted after having propagated for about two to three eddy-turnover times downstream, which corresponds well to other state-of-the-art methods for turbulence generation. Furthermore, we observe that numerical artefacts in the form of grid-scale convective structures in the mesoscale model enter the PALM domain, biasing the location of the turbulent up- and downdrafts in the LES. With these findings presented, we aim to verify the mesoscale nesting approach implemented in PALM, point out specific shortcomings, and build a baseline for future improvements and developments.

Funder

Bundesministerium für Bildung und Forschung

Publisher

Copernicus GmbH

Reference64 articles.

1. André, J. C., De Moor, G., Lacarrère, P., and du Vachat, R.: Modeling the 24-Hour Evolution of the Mean and Turbulent Structures of the Planetary Boundary Layer, J. Atmos. Sci., 35, 1861–1883, https://doi.org/10.1175/1520-0469(1978)035<1861:MTHEOT>2.0.CO;2, 1978. a

2. Baldauf, M., Seifert, A., Förstner, J., Majewski, D., Raschendorfer, M., and Reinhardt, T.: Operational Convective-Scale Numerical Weather Prediction with the COSMO Model: Description and Sensitivities, Mon. Weather Rev., 139, 3887–3905, https://doi.org/10.1175/MWR-D-10-05013.1, 2011. a, b, c, d

3. Baldauf, M., Förstner, J., Klink, S., Reinhardt, T., Schraff, C., Seifert, A., and Stephan, K.: Kurze Beschreibung des Lokal-Modells Kürzestfrist COSMO-DE (LMK) und seiner Datenbanken auf dem Datenserver des DWD, Tech. rep., Deutscher Wetterdienst, available at: https://www.dwd.de/SharedDocs/downloads/DE/modelldokumentationen/nwv/cosmo_de/cosmo_de_dbbeschr_version_2_3_201406.pdf?__blob=publicationFile&v=5 (last access: 13 August 2021), version 2.3, 2014. a, b, c

4. Baldauf, M., Gebhardt, C., Theis, S., Ritter, B., and Schraff, C.: Beschreibung des operationellen Kürzesfristvorhersagemodells COSMO-D2 und COSMO-D2-EPS und seiner Ausgabe in die Datenbanken des DWD, Tech. rep., Deutscher Wetterdienst, available at: https://www.dwd.de/SharedDocs/downloads/DE/modelldokumentationen/nwv/cosmo_d2/cosmo_d2_dbbeschr_version_1_0_201805.pdf?__blob=publicationFile&v=3 (last access: 13 August 2021), version 1.0, 2018. a, b

5. Brost, R. A., Wyngaard, J. C., and Lenschow, D. H.: Marine Stratocumulus Layers. Part II: Turbulence Budgets, J. Atmos. Sci., 39, 818–836, https://doi.org/10.1175/1520-0469(1982)039<0818:MSLPIT>2.0.CO;2, 1982. a, b, c, d, e

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