Near-surface ocean temperature variations across temporal scales in the coastal eastern Adriatic

Abstract

The article aims to quantify a multiyear ocean temperature change at a shallow (5 m) coastal site in the northeastern Adriatic. Measurements were taken between May 2014 and May 2021 with an hourly resolution, allowing for an extraction of temperature variations over longer-term, seasonal, synoptic, quasi-diurnal and hourly timescales. As expected for shallow waters, the seasonal influence is prevalent, while diurnal changes are quasi-persistent throughout the year. Marine heat waves and cold spells are the strongest during spring and summer months. Non-seasonal changes mostly guide longer-term (>10 days) variability, yet rapid temperature changes reach 2 °C/h during stratified seasons. Such rapid changes may impact benthic communities and the physiology of marine species, including bivalves. This is especially important in the era of global warming, in which environmental conditions are already pushed towards their thresholds, and where high-frequency variability analyses can be useful in introducing a precautionary approach for local climate change adaptation.