We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
What Caused the Large‐Scale Heat Deficit in the Subtropical South Atlantic Ocean During 2009–2012?
- Authors
Dong, Shenfu; Lopez, Hosmay; Lee, Sang‐Ki; Meinen, Christopher S.; Goni, Gustavo; Baringer, Molly
- Abstract
The subtropical South Atlantic hosts complex ocean circulation patterns and processes that transport heat to the North Atlantic, thereby playing an important role in global energy redistribution. This study uses several oceanic products to assess ocean heat changes in the subtropical South Atlantic and the associated atmosphere‐ocean processes. A particular focus is placed on the large heat deficit during 2009–2012, which is associated with cooling during 2008–2011 and subsequent warming. This heat deficit was largely driven by a sharp increase in the southward Ekman transport across 35°S during 2008–2011. The anomalous Ekman transport is connected to the persistent positive sea level pressure anomaly over the Atlantic sector of the Southern Ocean, caused by the Southern Annular Mode and the Pacific‐South American Modes. Although the overall correlations of these climate modes with the Ekman transport are modest during 1993–2016, the modes combined to produce large heat content anomalies during 2009–2012. Plain Language Summary: Recent studies have shown that changes in ocean heat content in the South Atlantic can have a pronounced impact on regional and global extreme weather events and long‐term climate variability. Motivated by these findings, this study addresses the physical mechanisms responsible for a large heat content deficit during 2009–2012, which is associated with cooling during 2008–2011 and subsequent warming during 2012–2013. Observation‐based examination of the two main forcing mechanisms for ocean heat content changes, air‐sea heat exchange, and ocean heat convergence indicates that the observed heat deficit is largely driven by oceanic heat transport divergence, especially the direct wind‐forced southward transport anomalies across 35°S. This anomalous southward transport is consistent with positive sea level pressure (SLP) anomalies south of 37°S and negative SLP anomalies to the north during this period. This spatial pattern of the SLP anomalies resembles the SLP spatial structure forced by cooling in the central Pacific. Key Points: The subtropical South Atlantic Ocean showed a large heat deficit during the 2009–2012 periodThis heat deficit is largely driven by oceanic heat transport divergence, especially the reduced Ekman transport across 35°SThe reduced Ekman transport is remotely forced in part by cooling in the central tropical Pacific
- Subjects
ANTARCTIC oscillation; ENTHALPY; MODES of variability (Climatology); HEAT; OCEAN
- Publication
Geophysical Research Letters, 2020, Vol 47, Issue 11, p1
- ISSN
0094-8276
- Publication type
Article
- DOI
10.1029/2020GL088206