Re : Zoekplaatje

Logisch toch? Ik zie over de lange termijn wel een verband. Misschien dat de correlatie het beste is als je de zwarte grafiek wat naar rechts verschuift.

We find as Skagseith et al. found, a strong correlation between temperature and the AMO index. Skagseth et al. suggest, and we agree with, that the strong similarity between these temperature series and the AMO index indicate that the climatic variation in the BS region ‘‘is a local manifestation of a larger-scale climatic fluctuation covering at least the entire North Atlantic Ocean.’’ We note however that the correlation could be fortuitous because the record length is relatively short. General circulation models and paleoclimatic data are necessary to study this phenomenon.

However, despite good qualitative agreement between the BS oceanic climate trends and other climate tendencies in the Arctic, we must draw attention to some caveats inherent to our work. First, there is some uncertainty in ‘‘connecting the dots’’ between a warmer BS and reduced sea ice cover in the central Arctic—the presumed link between the two observables, which is yet to be explained. One of the plausible explanations would be to link AW throughflow in the BS to a lower rate of seasonal sea ice growth in winter in the BS [Wu et al., 2004] and further downstream of the throughflow. However, AW sinks and thus may not have that much impact downstream on ice cover. Recent results suggest that the advection of warming near-surface water from the North Pacific Ocean to the Arctic Ocean through the Bering Strait may play a significant role in Arctic sea-ice retreat [Woodgate et al., 2006]. Thermohaline intrusions of relatively warm water from the Arctic boundary currents into the Arctic interior [McLaughlin et al., 2009] may play a role. Aerosols may also play a role [Shindell, 2007].

Prior to about 1970, there was generally above-average sea ice cover, with the maximum extent observed in the late 1960s. Since the late 1970s sea ice extent has decreased substantially [Comiso et al., 2008], whereas, simultaneously, AW has become warmer and perhaps more abundant in the BS. The warmer air and the gradual decrease of albedo of thinning ice in summer would cause melting from above. Additionally, the sea ice decrease may be due to heating from below, when the water mixing channels heat stored in subsurface layers toward the sea ice base. More and warmer AW may contribute to shortening or complete elimination of seasonal sea ice presence in some part of central and eastern Arctic. It is still not clear whether, or how much, subsurface AW has directly contributed to the substantial ice melting that has been observed during last 20 years in the central Arctic; another plausible explanation for an AW role in this process may be the BS impact on the Arctic climate via ocean-air interaction [Goosse and Holland, 2005].