Deep and abyssal ocean warming from 35 years of repeat hydrography. Issue 19 (9th October 2016)

• Record Type: Journal Article
• Authors: Desbruyères, Damien G.; Purkey, Sarah G.; McDonagh, Elaine L.; Johnson, Gregory C.; King, Brian A.
• Is Part Of: Geophysical research letters. Volume 43:Issue 19(2016)
• Page Start: 10, 356
• Page End: 10, 365
• Publication Date: 2016-10-09
• Subjects: repeat hydrography -- ocean heat content -- GO‐SHIP; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL070413
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Global and regional ocean warming deeper than 2000 m is investigated using 35 years of sustained repeat hydrographic survey data starting in 1981. The global long‐term temperature trend below 2000 m, representing the time period 1991–2010, is equivalent to a mean heat flux of 0.065 ± 0.040 W m −2 applied over the Earth's surface area. The strongest warming rates are found in the abyssal layer (4000–6000 m), which contributes to one third of the total heat uptake with the largest contribution from the Southern and Pacific Oceans. A similar regional pattern is found in the deep layer (2000–4000 m), which explains the remaining two thirds of the total heat uptake yet with larger uncertainties. The global average warming rate did not change within uncertainties pre‐2000 versus post‐2000, whereas ocean average warming rates decreased in the Pacific and Indian Oceans and increased in the Atlantic and Southern Oceans. Key Points: Observed oceanic heat uptake (33 ± 21 TW) below 2000 m during 1991–2010, majority (2/3) in deep layer (2000–4000 m) Temperature trends larger with lower uncertainty in the abyss (4000–6000 m) than in the deep (2000–4000 m) ocean Global warming rate did not significantly change from the 1990s to the 2000s but significant variability regionally