Observed and simulated turbulent kinetic energy (WRF 3.8.1) overlarge offshore wind farms Journal Article uri icon

Overview

abstract

  • Abstract. Because wind farms affect local weather and microclimates, parameterizations of their effects have been developed for numerical weather prediction models. While most wind farm parameterizations (WFP) include drag effects of wind farms, models differ on whether or not an additional turbulent kinetic energy (TKE) source should be included in these parameterizations to simulate the impact of wind farms on the boundary layer. Therefore, we use aircraft measurements above large offshore wind farms in stable conditions to evaluate WFP choices. Of the three case studies we examine, we find the simulated ambient background flow to agree with observations of temperature stratification and winds. This agreement allowing us to explore the sensitivity of simulated wind farm effects with respect to modeling choices such as whether or not to include a TKE source, horizontal resolution, vertical resolution, and advection of TKE. For a stably stratified marine atmospheric boundary layer (MABL), a TKE source and a horizontal resolution in the order of 5 km or finer are necessary to represent the impact of offshore wind farms on the MABL. Additionally, TKE advection results in excessively reduced TKE over the wind farms, which in turn causes an underestimation of the wind speed above the wind farm. Furthermore, using fine vertical resolution increases the agreement of the simulated wind speed with satellite observations of surface wind speed.;

publication date

  • July 10, 2019

has restriction

  • green

Date in CU Experts

  • November 5, 2020 2:08 AM

Full Author List

  • Siedersleben SK; Platis A; Lundquist JK; Djath B; Lampert A; Bärfuss K; Canadillas B; Schultz-Stellenfleth J; Bange J; Neumann T

author count

  • 11

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