Abstract
The continuous and significant rise of the sea surface temperature (SST) in the Eastern Mediterranean Sea over the past three decades is not uniform both in temporal and spatial scales. This study aimed to investigate the temporal evolution of the SST in the Cilician Basin on monthly to decadal scales within two partially overlapping periods (1983–2023 and 1995–2023) by utilising three datasets obtained with different methodologies. “The High-Resolution Daily Optimum Interpolation SST” (OISST V2.1), the fifth generation reanalysis (ERA5) “monthly averaged data on single-level”, and the available in-situ observations (1995–2023) were utilised to compare all datasets and analyse the temporal evolution of the SST in the region. The annual mean SST results of the OISST (0.043 ℃/year) and In-Situ (0.042 ℃/year) datasets were almost identical. In both datasets, the highest warming is recorded in fall, and June is recorded with a decreasing trend. In the ERA5 dataset, the SST is increased by 0.054 ℃/year, and the highest warming is recorded in summer. Continuous and consecutive positive SST anomalies have been observed since 2013. The highest three annual mean SSTs since 1983 were recorded in the last six years, and 2018 was the warmest year in the studied period. On the decadal scale, a cooling of the SST was recorded between 1983 and 1993, and the highest warming occurred in the following decade, between 1993 and 2003. The rise of the In-Situ SST in November and December was drastic, especially in 2017 and 2018. This excessive warming (low-efficient cooling) in the fall/early winter is of particular concern as it may affect the physical/biochemical characteristics of the water column, hence the circulation and coastal ecosystem.