Publication Date:
2022-05-25
Description:
Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 35 (2008): L22601, doi:10.1029/2008GL035619.
Description:
We analyze abyssal temperature data in the western North Atlantic Ocean from the 1980s–2000s, showing that reductions in Antarctic Bottom Water (AABW) signatures have reached even that basin. Trans-basin oceanographic sections occupied along 52°W from 1983–2003 and 66°W from 1985–2003 quantify abyssal warming resulting from deepening of the strong thermal boundary between AABW and North Atlantic Deep Water (NADW), hence a local AABW volume reduction. Repeat section data taken from 1981–2004 along 24°N also show a reduced zonal gradient in abyssal temperatures, consistent with decreased northward transport of AABW. The reduction in the Antarctic limb of the MOC within the North Atlantic highlights the global reach of climate variability originating around Antarctica.
Description:
NOAA and NSF supported the 2003 U.S.
CLIVAR/CO2 Repeat Hydrography Program reoccupations of the 52 W
and 66 W sections, led by Chief Scientists John Toole and Terrence Joyce,
respectively. The U.K. National Environment Research Council supported
the 2004 reoccupation of the 24 N section, led by Chief Scientist Stuart
Cunningham. The hard work of all contributing to the collection and
processing of data analyzed here is gratefully acknowledged. The NOAA
Office of Oceanic and Atmospheric Research and the NOAA Climate
Program Office supported the analysis.
Keywords:
Antarctic bottom water
;
Meridional overturning circulation
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf