Historically strong El Nino years do not result in large Arctic Sea Ice losses; however, strong La Nina events normally follow immediately after a strong El Nino event; and historically strong La Nina events do induce conditions that support large Arctic Sea Ice losses. Thus as our current strong El Nino event should likely dissipate by March 2016, expecting a high La Nina assisted Arctic Sea Ice loss by the end of August 2016 seems like a good bet.
Beg to differ, somewhat. I recently posted this at RealClimate:
Further to the discussion on EL/LN (ENSO) and correlation with ASI Extent lows, my original observation noted rough correlations between EN’s followed 1 or 2 years later by new lows. This observation was based on eyeballing graphs and included no other conditions affecting the ice. However, it is clear the ’07 low was strongly affected by winds and weather generally. Likewise, the lack of winds and relative cold correlated well with the last two years of rise in ASIE and this year almost certainly not hitting new lows. In fact, I had not called new lows, or even 2nd or 3rd new records in extent because I think all the open water makes high variation in extent *less* likely. The weather has cooperated to make that still true.
I think, in fact, it makes little sense to look for new lows in extent as the primary metric when it is so easy for ice to spread in open seas. Area and volume both tell us more about the *amount* of ice, anyways, which I have focused on since ’10. Unfortunately, we don’t have good records on those so rely on the continuity of the extent record to check for this correlation.
I went further back, eyeballing from an extent graph through 2010 or so with poor detail (what I could find) and a list of ENSO years and intensities. This is the rough. If anyone has more detailed resources and can nail this down better, please do.
Here is what I found going all the way back to the beginning of ASIE decline @ 1953-ish.
EN ’51 – ’54 = inception of ASI Extent decline.
EN ’57 – ’59 = Near New Low/New Low
EN ’65 – ’66 = Near New Low/New Low
EN ’68 – ’70 = New Low
EN ’72 – ’73 = possible correlation, some delay
EN ’76 – ’78 = New Low
EN ’79 – ’80 = New Low
EN ’82 – ’83 = New Low
EN ’86 – ’88 = New Low (’89,’90)
EN ’94 – ’95 = New Low
EN ’97 – ’98 = Drop from Previous (?)
EN ’04 – ’05 = Near New Low/New Low
EN ’04 – ’05/’06 – ’07 = New Low
EN ’09 – ’10 = New Low (’10, ’12)
EN ’15 – ’16 = New Low ’16,’17?
What about La Nina? First, I don’t care if the actual cause is LN or EN, the correlation with ENSO is the key. However, we have a problem, Houston. I didn’t check the full record of LN because I found this from recent years:
La Nina
’07-’08 After
’10-’11 After
’10-’11, ’11-’12 = New Low
If LN is following big melts, it can’t be contributing to them, so the correlation is already weaker than with EN. Also, the ’10-’11 EN could be said to be correlated with the ’12 low given the hypothesis of near new lows/new lows following EN’s by 1 or 2 years. Feel free to check the LN record, tho.
What I think is going on is the EN’s put a lot of heat into the ocean surface *and* the air, yes? I propose these waters and air temps propagate via multiple routes (directly, storm tracks, etc.) into the Arctic enhancing melt. We know melt from the bottom due to water temps is responsible for up to 2/3 of the ice melt, and also that it takes much longer for energy to propagate through the oceans than the atmosphere. It makes sense an EN correlation might be delayed.
It would be great to correlate wind and storm patterns and temps with all this. Let’s be clear: I am not saying ENSO *is the primary cause of melt*, only that there is what appears to be a strong correlation.
http://www.realclimate.org/?comments_popup=18643#comment-635199
