Bernacchia, Nicola
(2025)
Circulation analysis and characteristic time
scales in an urban canopy.
[Laurea magistrale], Università di Bologna, Corso di Studio in
Fisica del sistema terra [LM-DM270], Documento full-text non disponibile
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Abstract
The concept of ”city breathability”, namely the concept of ventilating the urban
environment, is a topic of growing interest within the scientific community, as it is strongly linked to the dangers that atmospheric pollutants can pose to human
health. Studying air circulation down to the smallest scales of the urban boundary layer allows for a general understanding of how pollutant concentrations are
transported within the city. Atmospheric pollutants in urban environments can
be harmful to health, particularly in relation to their residence time within the
urban canopy. For these reasons, the objectives of this thesis are to characterize
air circulation in two urban canyons in the city of Bologna and to provide turbulence time scales that can be used as indicators of pollutant residence time in the
air. To carry out these analyses,
data were selected from the dataset from the experimental field campaign con-
ducted in Bologna during the summer of 2023 within the framework of the H2020
I-CHANGE (Individual Change of HAbits Needed for Green European transition) project. Measurements were taken in Irnerio and Berti Pichat, two urban areas
with different morphological characteristics, streets orientation and vegetation cov-
erage. The study led to the characterization of four different snapshots of the air
circulations in the two canopies according to the different direction of the wind
approaching each canyon, highlighting differences in the
turbulent aspects of wind flow between the two areas, mainly due to the diverse
morphological and geometrical characteristics of the two areas and the uneven pres-
ence of vegetation in one site compared to the other. The use of time scales related
to mechanical turbulence, combined with the characterization of airflow regimes
and turbulent mechanisms favouring air refreshing through the canyon top inter-
face, proved effective in describing the temporal evolution of nitrogen monoxide
concentrations at street level.
Abstract
The concept of ”city breathability”, namely the concept of ventilating the urban
environment, is a topic of growing interest within the scientific community, as it is strongly linked to the dangers that atmospheric pollutants can pose to human
health. Studying air circulation down to the smallest scales of the urban boundary layer allows for a general understanding of how pollutant concentrations are
transported within the city. Atmospheric pollutants in urban environments can
be harmful to health, particularly in relation to their residence time within the
urban canopy. For these reasons, the objectives of this thesis are to characterize
air circulation in two urban canyons in the city of Bologna and to provide turbulence time scales that can be used as indicators of pollutant residence time in the
air. To carry out these analyses,
data were selected from the dataset from the experimental field campaign con-
ducted in Bologna during the summer of 2023 within the framework of the H2020
I-CHANGE (Individual Change of HAbits Needed for Green European transition) project. Measurements were taken in Irnerio and Berti Pichat, two urban areas
with different morphological characteristics, streets orientation and vegetation cov-
erage. The study led to the characterization of four different snapshots of the air
circulations in the two canopies according to the different direction of the wind
approaching each canyon, highlighting differences in the
turbulent aspects of wind flow between the two areas, mainly due to the diverse
morphological and geometrical characteristics of the two areas and the uneven pres-
ence of vegetation in one site compared to the other. The use of time scales related
to mechanical turbulence, combined with the characterization of airflow regimes
and turbulent mechanisms favouring air refreshing through the canyon top inter-
face, proved effective in describing the temporal evolution of nitrogen monoxide
concentrations at street level.
Tipologia del documento
Tesi di laurea
(Laurea magistrale)
Autore della tesi
Bernacchia, Nicola
Relatore della tesi
Correlatore della tesi
Scuola
Corso di studio
Ordinamento Cds
DM270
Parole chiave
Exchange processes,Turbulent scales,Urban canopy,Urban boundary layer,City breathability
Data di discussione della Tesi
24 Marzo 2025
URI
Altri metadati
Tipologia del documento
Tesi di laurea
(NON SPECIFICATO)
Autore della tesi
Bernacchia, Nicola
Relatore della tesi
Correlatore della tesi
Scuola
Corso di studio
Ordinamento Cds
DM270
Parole chiave
Exchange processes,Turbulent scales,Urban canopy,Urban boundary layer,City breathability
Data di discussione della Tesi
24 Marzo 2025
URI
Gestione del documento: