RELATIONSHIP BETWEEN THE SEA SURFACE AND SURFACE AIR TEMPERATURE: A CASE OF THE ISLAND OF HVAR (ADRIATIC SEA, CROATIA)

Relationship of Sea Surface Temperature (SST) and Surface Air Temperature (SAT) measured at the small island of Hvar (Adriatic Sea) are examined on annual and monthly time scales using data for a period of 55 years (1964-2018). The following three SST and SAT indices were analysed: (1) absolute minimum; (2) mean; (3) absolute maximum. The results highlighted a statistically significant increasing trend for all three SST analysed annual indices. In the case of SAT absolute minimum increasing trend is not statistically significant. For the other two indices the trends are statistically significant at the level, p<0.01. Monthly analysis for SST indices almost in all months (except October) have statistically significant increasing trends. In the case of SAT, a statistically significant increasing trend for all analysed indices occurred in summer (July and August). All results point out that the analysed region, especially small Adriatic islands are endangered of climate change, i.e. global warming during the summertime. Using the RAPS method on the minimum annual SST, a statistically significant shift upward was detected in 1988. Ten years later, in 1998, a statistically significant shift upward was detected on the mean and maximum SST and SAT indices. In the case of SAT minimum annual values, a statistically significant shift downward is detected, starting in 1979. In the analysed case of the Island of Hvar, the warming of SST indices is higher than the warming of SAT indices and occur during the whole year (except in October).