40 years of changes in sea surface temperature along the Western Iberian Coast

Beatriz Biguino; Carlos Antunes; Luísa Lamas; Luke J Jenkins; João Miguel Dias; Ivan D Haigh; Ana C Brito

doi:10.1016/j.scitotenv.2023.164193

40 years of changes in sea surface temperature along the Western Iberian Coast

Sci Total Environ. 2023 Aug 25:888:164193. doi: 10.1016/j.scitotenv.2023.164193. Epub 2023 May 15.

Authors

Beatriz Biguino¹, Carlos Antunes², Luísa Lamas³, Luke J Jenkins⁴, João Miguel Dias⁵, Ivan D Haigh⁴, Ana C Brito⁶

Affiliations

¹ Marine and Environmental Sciences Centre (MARE), Aquatic Research Network (ARNET), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal. Electronic address: bibiguino@fc.ul.pt.
² Instituto Dom Luiz (IDL), Universidade de Lisboa, 1749-016 Lisboa, Portugal; Departamento de Engenharia Geográfica, Geofísica e Energia, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
³ Instituto Hidrográfico (IH), Rua das Trinas 49, 1249-093 Lisboa, Portugal.
⁴ School of Ocean and Earth Science, University of Southampton, National Oceanography Centre, Waterfront Campus, European Way, Southampton SO14 3ZH, UK.
⁵ Centre for Environmental and Marine Studies (CESAM), Departamento de Física, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
⁶ Marine and Environmental Sciences Centre (MARE), Aquatic Research Network (ARNET), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal; Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.

PMID: 37196952
DOI: 10.1016/j.scitotenv.2023.164193

Abstract

Climate change is causing mean sea surface temperatures (SST) to increase worldwide. However, this increase has not been temporally or spatially uniform, with variations observed depending both on the period considered and the geographic region. In this context, this paper aims to quantify relevant changes in SST along the Western Iberian Coast over the last four decades, through the calculation of trends and anomalies of long-term time series of in situ observations and satellite-derived data. Potential drivers of SST changes were considered using atmospheric and teleconnections time series. Changes in the seasonal cycle of SST were also evaluated. We show that SST has increased since 1982, with regional variations between 0.10 and 0.25 °C per decade, with an increase in air temperature appearing to drive the SST trends along the Iberian coast. In the near-shore area, no significant trends or changes in the seasonal cycle of SST were observed, which is likely due to a buffer effect caused by the seasonal upwelling that characterizes the region. Recent decades show a slowdown in the increase rate of SST along the Western Iberian Coast. An upwelling intensification could justify this observation, along with the effect of teleconnections on the regional climate, such as the North Atlantic Oscillation (NAO) and the Western Mediterranean Oscillation Index (WeMOI). Our results suggest that the WeMOI plays a more important role in coastal SST variability than the other teleconnections. The present study quantifies regional changes in SST and enhances knowledge of the role of ocean-atmosphere interactions in regulating climate and weather conditions. Moreover, it provides a relevant scientific context to the development of regional adaptative and mitigation actions in response to climate change.

Keywords: Anomalies; Buffer effect; Climate change; Ocean-atmosphere interactions; Rising temperatures; Seasonality variability; Trends.