Εκτιμήσεις των μελλοντικών κλιματικών αλλαγών στη Μεσόγειο με τη χρήση περιοχικών κλιματικών μοντέλων

• Published in: Marine Chemistry
• Main Authors: Rousi, Eftychia, Ρούση, Ευτυχία
• Format: Doctoral or Postdoctoral Thesis
• Language: Greek
• Published: Aristotle University Of Thessaloniki (AUTH) 2014
• Subjects: Κλιματικές αλλλαγές; Περιοχικά κλιματικά μοντέλα; Πρότυπα τηλεσύνδεσης; Μεσόγειος; Γενικά μοντέλα κυκλοφορίας; Climate change; Regional climate models; Teleconnection Patterns; Mediterranean; General circulation models; Φυσικές Επιστήμες; Γεωεπιστήμες και Επιστήμες Περιβάλλοντος; Natural Sciences; Earth and Related Environmental Sciences; North Atlantic; North Atlantic oscillation
• Online Access: http://hdl.handle.net/10442/hedi/35162; https://doi.org/10.12681/eadd/35162

The aim of this study is an analysis of present and future climate change in the Mediterranean with the use of climate models. In this direction, a recognition of important atmospheric circulation patterns dominating over Europe is attempted and further their effects to climate parameters of the Mediterranean are studied. The methods of pattern recognition used are the Rotated Principal Component Analysis (rPCA) and the Self Organizing Maps (SOM). Three teleconnection patterns were chosen, the North Atlantic Oscillation (NAO), which is a basic variability mode that mostly affects the climate of Western Europe, the North Sea–Caspian Pattern (NCP) and the Eastern Mediterranean Pattern (EMP) that mainly affect eastern Mediterranean and the Balkan Peninsula. The patterns are studied on a seasonal basis for 500 hPa geopotential height anomalies over Europe based on reanalysis (NCEP/NCAR) and simulated data of the ECHAM5/MPI GCM, for reference (1971-2000) and future period (2071-2100). According to the results, both PCA and SOM methodologies capture the main variability mode over the study area, represented by the NAO pattern, but SOM is capable of capturing even less pronounced patterns, such as the NCP and the EMP. In the future simulations, the atmospheric circulation seems to be more pronounced with stronger teleconnection patterns over Europe. On the next step, the SOM method was used in order to redefine the centers of the teleconnection indices for each dataset and their timeseries were calculated. Days characterized by extreme teleconnection indices were taken into consideration in order to examine their effects on the climate parameters of temperature, precipitation, wind (speed and direction) and frequency of low pressure systems in the Mediterranean. The data consists of 3 Regional Climate Models (RCM) simulations (KNMI-RACMO2, MPI-M-REMO, ICTP-REGCM3), that are all forced by the same GCM (ECHAM5) and cover the reference and future period. One important result is that the effects of the teleconnection ...