Ref: SCART-2021-0045

Large eddy simulations of the Martian convective boundary layer: Towards developing a new planetary boundary layer scheme

Temel, Orkun ; Senel, Cem ; Porchetta, Sara ; Muñoz- Esparza, Domingo ; Mischna, Michael A. ; Van Hoolst, Tim ; van Beeck, Tim ; Karatekin, Ozgur

published in Atmospheric Research , Volume 250 (2021)

Abstract: The grid resolutions typically employed in atmospheric global circulation and mesoscale models are not sufficient to explicitly resolve the turbulence processes within the planetary boundary layer (PBL). turbulent fluxes are, therefore, fully parameterized in those models, based on empirical relationships for the mixing length scale using PBL schemes. However, microscale models use the large-eddy simulation (LES) technique to resolve turbulence processes. Here, we perform LES computations for the daytime Martian planetary boundary layer, ranging from weakly to strong convective conditions, using the Mars implementation of planetWRF, the MarsWRF model. In this study, our main focus is to investigate the turbulence statistics and turbulent spectrum utilizing our LES results. Then, using the computed turbulence kinetic energy and its dissipation rate, a generic formulation for the mixing length scale variation in the Martian convective boundary layer is proposed. This mixing length formulation is used to derive a Mars-specific PBL scheme and its performance is compared to the PBL scheme currently in use by the MarsWRF model, the MRF scheme. The proposed scheme is tested both in global and mesoscale simulations, which are used to evaluate the convective boundary layer height and near-surface meteorology conditions at the InSight landing site. The presently proposed PBL scheme results in an improved prediction of convective boundary layer height that agree better with the observational estimations acquired by radio occultations of Mars Express in comparison to the MRF scheme. Also, the prediction of near-surface winds at the InSight landing site is slightly improved.

DOI: /10.1016/ j.atmosres.2020.105381
Links: link

The record appears in these collections:
Royal Observatory of Belgium > Reference Systems & Planetology
Science Articles > Peer Reviewed Articles

 Record created 2021-01-31, last modified 2021-01-31