Estimating spatial distributions of design air temperatures for ships and offshore structures in the Arctic Ocean

Abstract

To provide some design references for ships and offshore structures to operate in the Arctic waters, we assessed the spatial distributions of design air temperatures (DATs) in the Arctic Ocean using a 40-year MERRA-2 air temperature reanalysis data (1981–2020). The DATs studied included the design temperature (tD), polar service temperature (PST), lowest anticipated service temperature (LAST), and record lowest temperature (RLT). Higher DATs were observed in the Atlantic Arctic sector than Pacific Arctic sector. The lowest DATs were mainly in the Central Arctic Ocean near Canada. Moreover, the PST was generally lower than the RLT in the summer months. The lowest yearly (summer) tD for the Northeast Passage, the Transpolar Sea Route, and the Northwest Passage were −34.2 °C (−8.7 °C), −33.4 °C (−16.2 °C), and −32.0 °C (−13.2 °C). They are used to determine the steel grade requirements for ships. Not all regions in the Arctic Ocean had a rising trend in the yearly extreme low temperature under Arctic warming, especially in some nearshore areas. Furthermore, a strategy was provided for LAST uncertainties caused by climate change. These results and treatments provided references for future polar engineering designs.