Sea-surface temperatures at the sub-Antarctic islands Marion and Gough during the past 50 years

Mélice, J-L; Lutjeharms, J R E; Rouault, M; Ansorge, I J

Sea-surface temperatures at the sub-Antarctic islands Marion and Gough during the past 50 years

Journal Article

2003

Journal Title

South African Journal of Science

Link to Journal

https://www.sajs.co.za/

Publisher

University of Cape Town

Department

Department of Oceanography

Faculty

Faculty of Science

Abstract

Sea-surface temperatures (SSTs) have been measured at Marion and Gough islands for nearly 50 years. These are some of the longest records of their kind in the sub-Antarctic. We present the trend, the seasonal cycle, and the time-frequency characteristics of the SST for both islands, which rose by 1.4°C at Marion Island and by 0.5°C at Gough Island over the 50-year period. Intermittent temperature oscillations, with periods of between 1 and 5 years, were observed throughout the record. A 5-year periodicity, compatible with an Antarctic CircumpolarWave signature, dominated after 1990 in both records. We also observed a strong low-frequency component with a period varying from 9.3 to 11.4 years at Marion Island, and a much weaker component with a period varying from 9.9 to 11.8 years at Gough Island.