BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Testing eddy compensation and eddy saturation in the Southern Ocea
 n - Dan Jones (British Antarctic Survey)
DTSTART:20131030T110000Z
DTEND:20131030T120000Z
UID:TALK47341@talks.cam.ac.uk
CONTACT:Dr Dan Jones
DESCRIPTION:The Southern Ocean (SO) is a unique and dynamic component of t
 he climate system.\nDue in part to its cold temperatures and large surface
  area\, the SO is an important region for\nthe transfer of heat\, momentum
 \, and climatically relevant gases between the atmosphere and\nthe interio
 r ocean. The strong westerly winds above the SO help drive a powerful curr
 ent\n(i.e. the Antarctic Circumpolar Current or ACC) that connects Earth
 ’s ocean basins in a\nglobal overturning circulation. In recent decades\
 , these winds have strengthened and shifted\npoleward. Despite this change
  in surface forcing\, no clear observational signal of the oceanic\ndensit
 y structure’s response has yet been detected. The eddy compensation hypo
 thesis posits\nthat changes in the direct wind-driven overturning circulat
 ion are balanced by changes in\nthe eddy-induced meridional circulation\, 
 effectively rendering SO stratification insensitive to\nwind stress. The c
 losely related (but not identical) eddy saturation hypothesis suggests tha
 t\nthe ACC is also insensitive to increased wind stress\, since additional
  energy ends up in the\nmesoscale eddy field instead of in the zonal mean 
 circulation. In this talk\, we examine the\nviability of the eddy compensa
 tion and saturation hypotheses on interannual\, decadal\, and\ncentennial 
 timescales.\n\nUsing a combination of theory and idealized numerical simul
 ations\, we show that it\nmay take the Southern Ocean many decades to cent
 uries to fully equilibrate with the world\nocean following a change in win
 d stress. As such\, it may be difficult to detect changes in\nisopycnal sl
 ope using the few decades of available observational data.  Our results su
 ggest that departures\nfrom the eddy compensation regime may be important 
 on decadal and centennial timescales\,\non which the interaction between r
 egional Southern Ocean circulation and global ocean circulation is signifi
 cant. As such\, we suggest that Southern Ocean overturning circulation\nis
  likely to strengthen in response to recent and future climate change\, wi
 th implications for\nthe global carbon cycle and climate.
LOCATION:British Antarctic Survey\, Room 330B
END:VEVENT
END:VCALENDAR