Jan 8, 2016

The North Atlantic Ocean and climate change in the UK and northern Europe

by
Wells, Neil C.
,
Weather
  • Indicates that the North Atlantic Ocean is showing changes in its circulation as represented by the Meridional Overturning Circulation (MOC) at 26°N in the last 10 years
  • Finds that the MOC can change significantly from one year to the next
  • Highlights that in 2009 it was observed that the MOC at 26°N reduced by 30% from its mean transport over a year and the northward heat transport was reduced by a similar amount, resulting in a cooling of the region from 30 to 40°N in the upper ocean (surface to 1000 m including the main thermocline); the event did not appear to influence the region poleward of 50°N
  • States the downward trend in the MOC from 2004 to 2012 is related to a decrease in the southward Upper Mid-Ocean transport, whilst the Gulf Stream shows little or no trend and the Ekman transport shows a small increase in the northward direction 
  • Notes the atmosphere in 2009–2010 also showed some interesting behavior, including exceptional cold winters in northern Europe associated with extremely low values of the North Atlantic Oscillation (NAO), coincident with MOC reduction, which leads to the observation that the role of the atmosphere in the changes in the MOC in this region, in particular on interannual and decadal timescales, is still not well understood