CR 61:157-176 (2014)  -  DOI: https://doi.org/10.3354/cr01250

ABSTRACT: Five indices of extreme precipitation are analysed over the Croatian Adriatic region on a seasonal and annual basis from 19 meteorological stations and a 3-member ensemble of the Regional Climate Model (RegCM3) simulations in the reference (1961-1990) and the near-future (2011-2040) climate. Future climate integrations are performed under the IPCC A2 emission scenario. Uncertainty of projected changes is assessed by comparing RegCM3 results with those from a subset of the ENSEMBLES regional climate models. Observed wet extremes exhibit large values in the areas close to the coastal mountains. Interannual variability in the number of very wet days (R95) and the fraction of precipitation associated with very wet days (R95T) is relatively large in all seasons, indicating a variable synoptic activity over the Adriatic region from one year to the next, as well as variable intense showers in the summer. The most prominent feature is a statistically significant decrease in the observed maximum number of consecutive dry days (CDD) during the autumn. When compared against the observations, RegCM3 overestimates observed precipitation and maximum 5 d precipitation amounts (Rx5d) in all seasons except the summer with statistically significant differences. Simulated number of dry days (DD) is generally underestimated and, consequently, R95 is mostly overestimated. Of all indices considered, R95T is best simulated by the model. The interannual variability of precipitation and indices is generally well reproduced. The projected changes in the mean and indices of extreme precipitation in the near future are weak overall, except in the autumn, in both the RegCM3 ensemble and selected ENSEMBLES models. Although the Mediterranean region is characterised as one of the regions most responsive to climate change, our results indicate that over the eastern Adriatic region, significant changes may not occur in the near future.

KEY WORDS: Precipitation extremes · Croatian Adriatic region · RegCM3 · Climate change