Expected heat load of Dubrovnik, Osijek, Rijeka, Zadar and Zagreb based on projections of regional climate models

U ovom radu ispitano je buduće stanje klime u pet hrvatskih gradova: Dubrovniku, Zadru, Rijeci, Zagrebu i Osijeku. To je napravljeno analiziranjem klimatskih indeksa FD, ID, SU, TR, DTR i ETR te srednjih, maksimalnih i minimalnih dnevnih temperatura dobivenih klimatskim simulacijama korištenjem dvaju različitih regionalnih klimatskih modela, RegCM4 i SMHIRCA4 horizontalne rezolucije 12.5 km, u kombinaciji s dva globalna klimatska modela, EC-EARTH i MPI-ESM-MR, za dva različita scenarija buduće klime, RCP 4.5 i RCP 8.5. Uspoređivanjem ovih varijabli u razdoblju 2041. – 2070. god. u odnosu na dosadašnju klimu, iz razdoblja 1991. – 2020. god., uočen je značajan porast srednjih, maksimalnih i minimalnih temperatura u svim korištenim kombinacijama regionalnih i globalnih klimatskih modela za sve promatrane gradove, a najveći je uglavnom u toplom dijelu godine. U Dubrovniku i Rijeci ovaj se porast pokazao najbržim, a zbog malih vrijednosti trendova u rasponu temperatura možemo zaključiti da se minimalne i maksimalne temperature u promatranim gradovima povećavaju podjednakim brzinama. U uvjetima toplije klime u svim se promatranim gradovima povećava broj dana s maksimalnom temperaturom zraka iznad 25 °C (posebice u Dubrovniku) i minimalnom iznad 20 °C (osobito u Rijeci i Zadru). Nadalje, u svim je gradovima dobiveno smanjenje broja dana s maksimalnom i minimalnom temperaturom ispod 0 °C.This paper examines the future climate state in five Croatian cities: Dubrovnik, Zadar, Rijeka, Zagreb and Osijek. This was done by analyzing climate indices FD, ID, SU, TR, DTR and ETR and mean, maximum and minimum daily temperatures obtained by climate simulations using two different regional climate models, RegCM4 and SMHI-RCA4, with a horizontal resolution of 12.5 km, combined with two global climate models, EC-EARTH and MPI-ESM-MR, for two different future climate scenarios, RCP 4.5 and RCP 8.5. By comparing these variables for the period 2041-2070 in relation to the current climate, from the period 1991-2020, a significant increase in mean, maximum and minimum temperatures was observed in all used combinations of regional and global climate models for all observed cities, and the largest increase was mainly in the warm part of the year. In Dubrovnik and Rijeka, this increase proved to be the fastest, and due to the small values of trends in the temperature range, we can conclude that the minimum and maximum temperatures in all of the observed cities are increasing at similar rates. In warmer climate conditions, in all observed cities,the number of days with a maximum air temperature above 25 °C increases (especially in Dubrovnik) as well as the number of days with minimum air temperature above 20 °C (especially in Rijeka and Zadar). Furthermore, a reduction in the number of days with maximum and minimum temperatures below 0 °C was obtained in all cities