Αστικοποίηση και κλίμα στο πλαίσιο της παγκόσμιας θέρμανσης: προκλήσεις για την ανθρώπινη υγεία

• Main Authors: Petrou, Ilias, Πέτρου, Ηλίας
• Format: Doctoral or Postdoctoral Thesis
• Language: Greek
• Published: University of Ioannina 2024
• Subjects: Τύποι καιρού; Αστική θερμική νησίδα (ΑΘΝ); Αστικοποίηση; Αστική υπερθέρμανση; Συνοπτικές ταξινομήσεις; Φασματική ταξινόμηση; Weather types; Urban heat island (UHI); Urbanization; Urban overheating; Synoptic classification; Spectral clustering; Γεωεπιστήμες και Επιστήμες Περιβάλλοντος; Φυσικές Επιστήμες; Μετεωρολογία και Επιστήμες της ατμόσφαιρας; Earth and Related Environmental Sciences; Natural Sciences; Meteorology and Atmospheric Sciences; Barents Sea; Greenland; Greenland Sea; Norwegian Sea
• Online Access: http://hdl.handle.net/10442/hedi/55789; https://doi.org/10.12681/eadd/55789

The scope of the present Doctoral Dissertation is to examine the changes in the frequency of weather types over Europe from 1979 to 2019, as well as the study of the urban heat island in 4 European cities (Athens, Barcelona, Luxembourg and Helsinki), during the summer. To meet this latter goal, regional classifications of weather types for each city were defined and the spatial and temporal characteristics of the intensity of the urban heat island effect, as well as the association of specific weather types with the urban overheating, were investigated during the summer (June–September) and during day and night, from 2008 to 2017. At a first stage, in order to investigate the changes in the frequency of weather types in Europe, a newly developed weather type classification system was used (Gridded Weather Type Classification 2- GWTC2), while monthly means of 2-m air temperature, 2-m dew point, and sea surface temperature were obtained from the recent ERA5 reanalysis database of the European Center for Medium-Range Weather Forecasts (ECMWF), in order to analyze the meteorological background of weather types frequencies trends. The obtained results revealed a significant increase in the frequency of warm weather types since 1979, while at the same time, most cold weather types show a significant decrease. The most notable changes in the frequency of weather types occurred primarily over the sea areas of north Europe and secondarily in the region including southern and central Europe, while increases (sea surface temperature and dew point) occurred (3-4 °C) in the polar sea areas (Norwegian Sea, Barents Sea and Greenland Sea). At a second stage, for each city a definition of local weather types for the 70-year period (1950–2020) was conducted. For this purpose, data obtained from the NCEP/NCAR database and are daily values (12UTC) of the following parameters from 1950 to 2020: 500 and 1000 hPa geopotential heights, 850 hPa temperature, and 850 hPa specific humidity, 2m temperature, specific humidity, 10m zonal and ...