Warming of the global ocean : consistency of thermal and altimetric fields and dominance of descending density surfaces

Sirpa Hakkinen (NASA Goddard Space Flight Center, United States)


Peter B. Rhines (University of Washington, USA); Denise Worthen (Wyle STE Group/NASA GSFC, USA)

Event: 2015 Ocean Surface Topography Science Team Meeting

Session: Science III: Large scale and global change ocean processes: the ocean's role in climate

Presentation type: Type Poster

We have investigated the multidecadal warming and interannual and decadal heat content changes in the upper ocean from observational data sets and from a modeled state estimate. Multidecadal warming is dominated by a contribution from deepening of the mid-thermocline isopycnals, resulting in an expansion of the subtropical mode water volume, rather than shifts of the temperature/salinity relationship. In fact temperatures of the same mode waters have cooled slightly. The contribution from this volume increase outweighs the surface warming contribution in the upper ocean heat content. The multidecadal isopycnal sinking has been the strongest over the southern basins. On interannual to decadal scales, sinking and shoaling of density surfaces dominates ocean heat content changes, while the contribution from temperature changes along density surfaces decreases as time scales shorten. Decomposition of ocean heat content changes into heaving and isopycnal temperature changes is shown to provide insight to the satellite sea surface height measurements of the last two decades.

Poster show times:

RoomStart DateEnd Date
Grand Ballroom Foyer Thu, Oct 22 2015,11:00 Thu, Oct 22 2015,18:00
Sirpa Hakkinen
NASA Goddard Space Flight Center
United States