Global and regional evolution of sea surface temperature under climate change

Abstract

Sea surface temperature (SST) has important local and remote influence on global climate through the distribution and transport of heat and moisture, which in turn affect precipitation and air temperature patterns across the globe. Thus, this work aims to assess the worldwide regionalization of the SST evolution for the 21 st century under the influence of climate change by means of: 1) division of the worldwide SST data in regions applying a K-means cluster procedure and validation of the most suitable CMIP5 models by a comparative analysis with SST data from Era-Interim reanalysis; 2) calculation of SST trends along the 21 st century and assessment of future SST differences between RCP 4.5 and RCP 8.5 greenhouse gas emission scenarios and historical SST data. Global climate model (GCM) projections show a SST warming worldwide although with different intensity depending on the region. Northern Hemisphere regions present a higher seasonal thermal amplitude comparing with equivalent regions in the Southern Hemisphere. Northern Hemisphere has also a higher annual SST increment than clusters in the Southern Hemisphere, independently of the future time period and climate scenario. The Northern Sub-Tropical cluster (STRN) shows the highest significant increment (4.34 °C on RCP 8.5). Under the RCP 4.5 climate scenario, SST trends from 1975 to 2100 range from 0.075 °C dec −1 at South Polar cluster (PRS) to 0.21 °C dec −1 at STRN cluster. Relatively to RCP 8.5 climatic scenario, SST trends change from 0.13 °C dec −1 at PRS cluster to 0.36 °C dec −1 at the North Polar cluster (PRN). • Identification of CMIP5 models with best SST performance. • The optimal worldwide SST division is eight clusters. • Northern Hemisphere clusters will present a higher SST increment.