Mid-21st century climate and weather extremes in Cyprus as projected by six regional climate models

摘要

We present climate change projections and apply indices of weather extremes for the Mediterranean island Cyprus using data from regional climate model (RCM) simulations driven by the IPCC A1B scenario within the ENSEMBLES project. Daily time-series of temperature and precipitation were used from six RCMs for a reference period 1976-2000 and for 2026-2050 ('future') for representative locations, applying a performance selection among neighboring model grid-boxes. The annual average temperatures of the model ensemble have a ± 1.5℃ bias from the observations (negative for maximum and positive for minimum temperature), and the models underestimate annual precipitation totals by 4-17%. The climatological annual cycles for the observations fall within the lcr range of the 6-model average, highlighting the strength of using multi-model output. We obtain reasonable agreement between models and observations for the temperature-related indices of extremes for the recent past, while the comparison is less good for the precipitation-related extremes. For the future, the RCM ensemble shows significant wanning of 1℃ in winter to 2℃ in the summer for both maximum and minimum temperatures. Rainfall is projected to decrease by 2-8%, although this is not statistically significant. Our results indicate the shift of the mean climate to a warmer state, with a relatively strong increase in the warm extremes. The precipitation frequency is projected to decrease at the inland Nicosia and at the coastal Limassol, while the mountainous Saittas could experience more frequent 5-15 mm/day rainfall. In future, very hot days are expected to increase by more than 2 weeks/year and tropical nights by 1 month/year. The annual number of consecutive dry days shows a statistically significant increase (of 9 days) in Limassol. These projected changes of the Cyprus climate may adversely affect ecosystems and the economy of the island and emphasize the need for adaptation strategies.