Very recent scientific publications show that the North Atlantic heat content and surface temperatures have been cooling significantly, and so may lead to a rebound in Arctic sea ice in the region. Already Arctic sea ice has stabilized over the past 10 years and Greenland has shown a surprising ice mass gain.
Kenneth wrote about this here not long ago.
Climate scientists agree that variations in the North Atlantic temperatures and ocean currents have a great impact on sea ice in the North Atlantic Arctic region and Europe’s climate.
Dramatic fall in North Atlantic heat content
For example recent findings published in Nature by a team led by David J. R. Thornalley of Department of Geography, University College London, show that the heat content of the North Atlantic from zero to 700 meters depth has cooled the most dramatically since the 1950s:
North Atlantic ocean heat content (OHC) dives. Source: Thormalloy et al, Nature.
In the 1970s most scientists believed an ice age was approaching after the surface temperature of the North Atlantic had cooled sharply from its 1950s peak.
Another very recent publication appearing in the Geophysical Research Letters by a team of researchers led by D.A. Smeed of National Oceanography Centre, Southampton, UK shows that surface and subsurface temperatures of the North Atlantic have fallen to their lowest levels in in more than 30 years:
The researchers suspect that the decreased lower temperatures are related to the Atlantic Meridional Overturning Circulation (AMOC), which is a powerful system of currents in the Atlantic involving the northward flow of warm water in the upper layers of the Atlantic and a southward flow of colder, deep waters which are part of the thermohaline circulation.
Changes in the Atlantic Meridional Overturning Circulation (AMOC) have significant impacts on North Atlantic climate. Source: R. Curry, Woods Hole Oceanographic Institution/Science/USGCRP
The scientists theorize that melting Arctic sea ice may be responsible for the recent changes, but this remains highly speculative as the data to support this is extremely sparse. Meanwhile other scientists believe it has all more to do with multidecadal scale ocean cycles that have occurred throughout history.
Warming changes over to cooling
Another team of scientists led by Christopher G. Piecuch published a study in the journal Geophysical Research Letters here which shows that the subpolar North Atlantic (SPNA) upper ocean and sea‐surface temperature trends reversed from warming during 1994–2004 to cooling over 2005–2015.
The authors write that the region “is subject to strong decadal variability”, meaning natural cycles are at play. The authors present the following chart, which shows that the North Atlantic heat content has fallen sharply since 2010.
So is it any surprise that Arctic sea ice has stabilized in the wake of the North Atlantic cooling and that Greenland is putting on gigatons of added ice?
Veteran meteorologist Joe Bastardi of WeatherBell Analytics has said repeatedly that when ocean heat content in the regions adjacent to the Arctic falls, it’s only natural for sea ice to recover, and vice versa when ocean heat content rises. Arctic ice extent fluctuates along with the natural Atlantic and Pacific ocean cycles. It has little to do with trace gas CO2.
July 4, 2018 at 08:16AM