The wind turning in the atmospheric boundary layer (ABL), the angle between the surface friction and wind just above the ABL, is greatly affected by the interaction between turbulence, Coriolis effects and density stratification within the layer. The wind-turning angle can be used as an indicator of cross isobaric mass flow which is notable in the formation and lifespan of synoptic scale cyclones (Holton & Hakim 2013, Beare 2007). It is therefore also good an indicator of how parameterization of sub-grid processes can affect outcome in climate and numerical weather prediction models.
By examining different ways of modelling turbulence in the ABL and boundary conditions we aim to find an explanation for why many state-of-the-art numerical weather prediction and climate models have such different results for the wind turning amongst themselves and compared to observations and large eddy simulations (LES). As a benchmark for our study, we use the first GEWEX Atmospheric Boundary-Layer Study (GABLS1) (Svensson & Holtslag 2009).
We anticipate to find variations in the representation of the turning of the wind by running suites of experiments by exploring parameter variations using a single column model of the ABL. We vary surface boundary conditions and internal turbulence parameterization parameters, and different temporal and vertical resolutions.
In the study we will use LES data (Sullivan et al. 2016), supersite observations, worldwide dataset of radio soundings (the Integrated Global Radiosonde Archive), and climate models.
References
Beare, R. J., 2007, ‘Boundary Layer Mechanism in Extratropical Cyclones’, Quarterly Journal of the Royal Meteorological Society, 133 (623), 503-515.
Holton, J. R. & Hakim, G. J, 2013, An Introduction to Dynamic Meteorology, 5th edn Academic Press, Oxford.
Svensson G. & A. A. M. Holtslag, 2009, ‘Analysis of model results for the turning of the wind and related momentum fluxes in the stable boundary layer’, Boundary Layer Meteorology, 132 (2), 261-277.
Sullivan, P. P., Weil, J. C., Patton, G., E., Jonker, H., J., J. & Mironov, D., V., 2016, ‘Turbulent Winds and Temperature Fronts in Large-Eddy Simulations of the Stable Atmospheric Boundary Layer’, Journal of the Atmospheric Sciences, 73 (4), 1815-1840.
How to cite: Þórarinsson, P. Á., Svensson, G., and Wallin, S.: Wind Turning in the Atmospheric Boundary Layer from Differences in Turbulence Parameterization and its Impact on Climate Modelling Results , EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-561, https://doi.org/10.5194/ems2022-561, 2022.
