Long-term precipitation variability in the Ionian Islands, Greece (Central Mediterranean): climatic signal analysis and future projections

Abstract

The present study examines the variability of the precipitation regime across the Ionian Islands complex, Greece (Central Mediterranean), for a period spanning more than one century. Significant negative long-term linear trends in the annual precipitation totals are observed, more pronounced in the southern parts of the studied area, while a climatic discontinuity possibly occurred during the 1970s, manifested first in the southern Ionian. Statistically significant nonlinear trends and subdecadal intermittent oscillations were detected using Monte Carlo singular spectral analysis. The correlation of the winter precipitation variability at Ionian complex with the North Atlantic Oscillation anomalies was also investigated and extended in the frequency domain. Finally, future projections were performed using an ensemble of Regional Climatic Models. Model simulations suggested a decrease of the order of ∼20% or more in the mean annual precipitation of the area by the end of the century.

On the relationships between forest fires and weather conditions in Greece from long-term national observations (1894–2010)

“…Precipitation trends were not significant, but a positive long-term tendency was observed in the amount of spring precipitation and a negative one in the summer precipitation. Autocorrelation peaks found at 7 years in the winter, spring and fire-season precipitation, are possibly associated with the 7-8-year oscillatory mode of NAO (Kalimeris et al 2012). Climatic signals in the 3.5-year band related to ENSO have been reported by many researchers.…”

Temporal variations and change in forest fire danger in Europe for 1960–2012

“…This is the main reason for the identification of significant breakpoints in the Spanish data but not in the Greek data. However, respective breaks in the mean air temperature time series over various regions in Greece in the early 1970s and middle 1990s (Nastos et al, 2011;Kolokythas and Argiriou, 2013) and in the precipitation time series between 1970 and 1980 (in the broader sense) (Pnevmatikos and Katsoulis, 2006;Feidas et al, 2007;Kalimeris et al, 2012) lead to the conclusion that an actual break in FWI series in the decade between 1970 and 1980 is also plausible. It should be noticed, however, that further testing is required in order to identify whether the breakpoints are artificial and due to exogenous variables or whether they actually indicate altering periods in the FWI values.…”

“…The annual number of fires and area burnt was strongly correlated with the maximum temperatures and summer heat waves. An evaluation of FWI performed recently using fire observations of a 15-year period for Greece confirmed that the index is capable of predicting fire occurrence (Karali et al, 2014). Additionally, Dimitrakapoulos et al (2011a) found that there was a positive correlation between the annual drought and fire occurrence in Greece during the years 1961-1997.…”

Temporal variations and change of forest fire danger in Europe in 1960–2012

“…Similarly, the mean annual air temperature in Greece was found to exhibit cooling trends from early 50s to mid-70s, then stabilizing at low levels before increasing again after early 90s (Nastos et al, 2011). Regarding precipitation, there were some marked breaks between the period 1971-1978 in some weather stations in the Ionian islands (north-west Greece) indicating shifts in the time-series towards reduced precipitation amounts during the latter periods (Kalimeris et al, 2012). According to Feidas et al (2007) an approximation of the starting period of decreasing trend of the precipitation amounts in Greece is the decade between 1974 to 1984.…”