RT info:eu-repo/semantics/article
T1 Wind Flow Analysis Beyond Orographic Effects: A Direction Turning-Gradient Approach for Urban Impact Quantification in Germany
A1 Pérez Bartolomé, Isidro Alberto
A1 García Pérez, María Ángeles
A1 Valdés Lorenzo, Orelvis
K1 Física aplicada
K1 Meteorología
K1 Ingeniería civil
K1 Urbanismo
K1 Ciencias atmosféricas
K1 Rosa de los vientos
K1 Campo de direcciones
K1 Mesoescala
K1 Ventilación urbana
K1 2501 Ciencias de la Atmósfera
K1 2502 Climatología
AB Wind direction is a variable that plays a secondary role in wind analyses since air flow is first studied. This paper focuses on its behaviour in ten cities and at two rural sites to investigate urban impact on wind direction. The database covered 18 years with a resolution of 1 km2, and hourly values were used. Two main procedures were followed. The first calculated the wind rose with high angular resolution from the average wind in each region studied as opposed to the usual calculations, where wind direction is measured at only one site. Two smoothing procedures were posited to acquire information about the data structure and specific details in one-degree roses. Bandwidth selection was based on the agreement with observations. Results revealed that westerly directions prevailed, although three patterns were observed. The most frequent was formed by a wide westerly sector, which may be attributed to synoptic flow, followed by wind roses with well-determined directions, such as Munich, where a mixture of relief and synoptic pattern could explain the rose shape. Finally, orographic influence is noticeable in specific roses, such as in Cologne, where the Rhine valley influence prevails. The second procedure is based on the direction turning field followed by the gradient calculation. This analysis was performed following wind direction, and two noticeable patterns of clear turning changes were occasionally found. The first pattern was formed by very close turning centres, which appear to be linked to the city, such as in Frankfurt for the easterly flow with a turning of around 65 degrees. Stuttgart, where the direction rose was barely affected by orographic features, showed a similar value of direction turning for the southerly flow, although following a different pattern formed by turning bands. Robust statistics showed the urban-rural contrast. Finally, three groups may be formed following the response against the turning field, with the weakest being for the largest cities –Berlin and Hamburg– where pollutant dispersion could prevail. An intermediate response was observed for most of the studied sites. However, Stuttgart and Frankfurt stood out due to their accused turnings that might determine complex pollution transport.
PB Springer Nature
SN 2509-9426
YR 2026
FD 2026
LK https://uvadoc.uva.es/handle/10324/83728
UL https://uvadoc.uva.es/handle/10324/83728
LA eng
NO Earth Systems and Environment (online record)
NO Producción Científica
DS UVaDOC
RD 22-mar-2026