Inside Barents Ice Crystal Ball
By Paul Homewood
More from Ron Clutz on how changing North Atlantic currents affect Arctic ice extent:
On a previous post (here), I linked to a recent study positing that variations in Barents Sea ice extent are predictive of Arctic extent for at least 1-2 years later. In other words, they concluded based upon measurements of ice extent and ocean heat transfers: As winter ice extent goes in Barents Sea, so goes annual ice extent across the Arctic ocean. The physical cause is changing fluxes of warm North Atlantic water penetrating through the Barents Sea into the rest of the Arctic. They acknowledge that other factors, especially winds are also in play, but believe that the ocean influx (also affected by winds) makes the largest influence. The full study is here.
Arctic Ice Dynamics
Here’s how researchers are connecting the dots:
NAO (North Atlantic Oscillation)► BSO(Heat transport by Atlantic Water (AW) through Barents Sea Opening)► Winter ice extent in Barents Sea► Winter ice extent in Arctic Ocean► Annual ice extents in Barents and Arctic Ocean.
A key scientist in this work is Randi Ingvaldsen of Geophysical Institute, University of Bergen, Institute of Marine Research. Several of her published articles are part of her doctoral thesis available here. It comprises an informative look into the extensive body of research in this area.
The Barents Sea climate fluctuates between warm and cold periods. By comparing decade by decade we found that although the 1990s had high temperatures, both the 1930s and the 1950s were warmer. This indicates that the warming of the 1990s may very well be related to natural variability rather than anthropogenic effects.
The above results indicate a positive correlation between the NAO winter index and the area occupied by AW, a result clearly evident when investigating the total area across the BSO occupied by AW (Figure 6d). Earlier investigations have shown a positive correlation between the NAO winter index and the mean AW temperature in the BSO (also evident in
Figure 6e). This means that both the temperature and the extent of AW increase with increasing NAO winter index (Figure 6 a and d-e), although with different lags.
In summary, this preliminary investigation has shown that both the mean temperature and lateral extent of AW in the BSO is positively correlated to the strength of the Icelandic low, although with lags.
Read the full story here.