Testing Various Morphometric Methods for Determining the Vertical Profile of Wind Speed Above Krakow, Poland

Abstract

Various morphometric methods used for wind-speed determination in urban areas inside the roughness sublayer have been tested in Krakow, Poland, using a hybrid modelling system. The hybrid modelling system combines the classic numerical meteorological modelling using ALADIN, MM5, and CALMET models with empirical, non-logarithmic relations determined on the basis of a wind-tunnel experiment. In the hybrid modelling system, the horizontally-averaged wind speed is determined using the displacement height d, roughness length z 0 , and an attenuation coefficient α. These parameters are determined using laser scanning data obtained in the MONIT-AIR project. The variability of the selected morphometric parameters in Krakow, the role of the size of the area from which they are determined and the consequences of replacing the frontal area index by the plan area index are analyzed. The different methods used to determine d, z 0, and α are compared and the correctness of the procedures describing the wind profile are verified by comparisons with wind-speed data from road stations, with the wind speed measured between the traffic lanes or at the roadside at a height of 4 m, at standard meteorological stations, and from masts situated on buildings. It is shown that the use of a parametrization based on large-eddy simulations prepared for explicitly resolved buildings in Tokyo and Nagoya in Japan, and taking the maximum instead of the average height of building in empirical relations, significantly improves the modelling results, especially above the average height of buildings.

Archives of Environmental Protection

“…Such an analysis carried out for several years of publishing the forecasts showed that the most common cause of misses in PM 10 forecasts in Krakow are difficulties in forecasting wind speed in the city and a delay of several hours in response to changing wind conditions. As shown by the research carried out in Krakow (Godłowska & Kaszowski 2019), if in the FAPSS system one applies the parameterization of wind within canopy layer developed with the use of large--eddy simulation (Kanda et al 2013), it will enable a better description of the behavior of meteorological parameters important for the transport of pollutants in the city. Due to the widespread availability of data from laser scanning, it is possible to determine the morphometric parameters of cities necessary for this parameterization.…”

Analysis of wind energy resources from high rise building for micro wind turbine: A review

“…Where U H represent velocity of wind at the height H, “a” is constant depends on the building morphology (Godłowska and Kaszowski, 2019).…”

“…When seen from below the average building height, wind speed exhibits an exponential distribution. Where U H represent velocity of wind at the height H, ''a'' is constant depends on the building morphology (God1owska and Kaszowski, 2019).…”