Revisiting the Meteor 1925–1927 hydrographic dataset reveals centennial full‐depth changes in the Atlantic Ocean. Issue 10 (31st May 2013)

• Record Type: Journal Article
• Authors: Gouretski, Viktor; Jungclaus, Johann H.; Haak, Helmuth
• Is Part Of: Geophysical research letters. Volume 40:Issue 10(2013:May)
• Page Start: 2236
• Page End: 2241
• Publication Date: 2013-05-31
• Subjects: ocean climate change -- ocean heat content -- centennial temperature changes; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/grl.50503
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract : [1] The hydrographic data set of the German Atlantic Expedition (GAE) 1925–1927 is compared with the contemporary profiling float and ship‐based hydrography to reveal full‐depth changes in the Atlantic Ocean between 19°N and 64°S. The volume‐mean warming over the last 80 years amounts to 0.119 ± 0.067 °C, accompanied by an increase in salinity of 0.014 ± 0.010. A clear vertical structure of these changes is observed: on average, the ocean has warmed by 0.272 ± 0.093 °C and became saltier by 0.030 ± 0.014 down to about 2000 m, but cooled and freshened slightly in the deeper layers. These changes can be traced throughout the whole hydrographic survey, indicating the basin‐wide character of the observed changes on a centennial timescale. The observed warming is consistent with climate model simulations over the 20th century, suggesting an attribution to anthropogenic forcing. Comparison with the pre‐GAE cruises reveals no discernible warming between the 1870s and 1906/1911. Key Points: Atlantic Ocean warmed /cooled above/below 2000 m since 1900s Atlantic Ocean more/less saline above/below 2000 m since 1900s Upper 2000 m warming started no earlier than the begin of the 20th century