Understanding and modelling of multiscale phenomena in the urban atmosphere

Abstract

Η διατριβή αφορά τη μελέτη αλληλεπίδρασης μεταξύ των φυσικών διεργασιών στην ατμόσφαιρα και παράλληλα η εισήγηση μεθόδων ώστε τα διάφορα προγνωστικά μοντέλα ατμοσφαιρικής ροής να μοντελοποιούν με συνεκτικό τρόπο αυτές τις διεργασίες, ανάλογα με την κλίμακα μελέτης του φαινομένου. Η προτεινόμενη μέθοδος είναι η πολυκλιμακωτή ανάλυση (Multiresolution Analysis) με χρήση του μετασχηματισμού κυματιδίων (Wavelet Transform).

Atmosphere is host of a wide range of phenomena taking place over a wide range of spatial and temporal scales. The motivation of this work is to investigate the interactions between different atmospheric processes that occur in this range of spatial and temporal scales by explicitly addressing this mutli‐scale nature. Specifically, the Multi-Resolution Analysis (MRA) is used on real urban‐morphology data. The analysis demonstrates the capacity of MRA for multi‐scale representation and its advantages for multi‐scale and multi‐resolution numerical modelling. Besides the scale-adaptive and spatially-varying parametrization and representation of urban-related data, monitored meteorological and air-quality data were collected from a sub-urban station in the form of time-series and they were analysed using multi-fractal analysis to gain insight into the multi-scale behavior of the sub-urban atmosphere.