Μείωση της βροχόπτωσης στην Α. Μεσόγειο και η σχέση της με το φαινόμενο Enso: διερεύνηση με τις μεθόδους της δενδροκλιματολογίας: [υπό] Δημητρίου Δ. Σαρρή

• Published in: Forest Ecosystems
• Main Authors: Sarris, Dimitrios, Σαρρής, Δημήτριος
• Format: Doctoral or Postdoctoral Thesis
• Language: Greek
• Published: University of Patras 2008
• Subjects: Κλιματική αλλαγή; Βροχόπτωση; Δείκτης της νότιας κύμανσης (SOI); Δείκτης της βορειοατλαντικής κύμανσης (ΝΑΟΙ); Αυξητικοί δακτύλιοι; Ξηρασία; Ελλάδα; Climate changes; Precipitation; Pinus halepensis; Southern oscillation index (SOI); North Atlantic oscillation Index (NAOI); Tree-rings; Drought; Greece; Φυσικές Επιστήμες; Βιολογία; Natural Sciences; Biological Sciences; Pacific; Soi; North Atlantic; North Atlantic oscillation
• Online Access: http://hdl.handle.net/10442/hedi/17960; https://doi.org/10.12681/eadd/17960

The Southern Oscillation Index (SOI) describes atmospheric circulation in the eastern tropical pacific related to ENSO (El Nino-Southern Oscillation), a phenomenon of global climatic significance. After the late 1970s, SOI’s strongest negative phase in 150 year was found to coincide with the strongest positive phase of the North Atlantic Oscillation Index (NAOI) in 180 years. Correlation analysis between SOI and NAOI during 1950-2007 revealed a statistically significant connection between the 20 strongest negative phases of the Sept.-Nov. SOI and the following winter’s (Dec.-Feb.) NAOI phases only after 1978. Similarly, the 20 strongest positive phases of the Oct.-Dec. and Nov.-Jan. SOI of 1950-2007 produced a statistically significant correlation with the following winter’s (Dec.-Feb.) NAOI phases after the late 1970s. Such relationships coincided with reduced winter precipitation in the eastern Mediterranean. If these SOI-NAOI connections hold, the possibility exists to forecast winter precipitation conditions in regions effected by NAO from the previous autumn’s SOI state (with even a 90% accuracy for regions of Greece). Annual radial stem increment was analysed in Pinus halepensis subsp. halepensis and Pinus halepensis subsp. brutia trees for Thermo-Mediterranean vegetation zones of the Greek islands of Zakinthos, Skiros, Samos and Crete (Ierapetra). Tree-ring width was found to be very sensitive to precipitation and produced a statistically significant correlation with annual rainfall from mean of 37 meteorological stations of the eastern Mediterranean. Tree-rings also indicated that annual rainfall reached its lowest values in nearly 200 years after the 1970s. This reduction in growth coincides with recent global warming. Thus, it is in line with IPCC (2007) climate model projections’ that the Mediterranean will experience a significant decline in precipitation as global warming progresses, as was the case in the recent past. It also raises the question whether recent SOI-NAOI links (involved in the recent ...