I see everyone posting graphs of average annual ENSO relative to the minimum extent. That's where the least ENSO influence is expected.
I don't see why this would be. Regardless of the time of year energy is transferred, is it not the total transferred that matters in the end? If an EN, for example, pushes ice melt in the Spring, that's still less ice to be melted. Etc.
ENSO's affects the ice in two ways that I can think of.
1. Directly: The influence of warm pacific humidity on the ice is visually undeniable.
Yes, I know of two studies that say this, though they looked at/found different effects, iirc.
2. Indirectly: A positive ENSO means, in general, a warmer world. A warmer world means, in general, more ice melt.
This would seem logical, yes. Scientific? Should be, but... the pedant(s) will say if not proven, it's not so!
I agree with you.
Then there is the problem of perspective. You are all looking at September minimum extent vs annual average ENSO.
In my case, I'm looking at your second effect. I think the immediate effect of heat and misture is clearly happening, but is the goosing of atmospheric heat content and ocean surface heat content having a long-term effect that comes into play directly with the ice? I think there is enough correlation for investigation. (Others disagree, but who cares? If I like ice cream and you don't, I go buy some, you don't. Don't go throwing out others' ice cream because you don't like ice cream, go do something else!
ENSO must have it's highest effect on the Pacific side of the Arctic.
It seems some of the effects in one or both of the papers I saw was a counter-intuitive response w/ effects in unexpected places, but I may be misremembering. However, wrt to ocean surface heat, or other, content, it would seem this would be true.
ASI response must have a lag to ENSO
Given how long it takes for the world's oceans' water to move about the planet, agreed.
ASI response to ENSO is much greater now that the thick ice is gone.
Logical, but true? As stated elsewhere, yes, I think so.
By increasing water content in the atmosphere, snow fall might be increased, the oppossite applies to La Niña.
I have never looked at this issue. Insulating effect? Melt effect? Hmmm...
If interested, here is my metric: Two years from the end an El Nino should show some relatively low numbers in one or more of the three measures that are commonly used: ASIE, ASIA, and/or ASIV. (
****I have only looked at extent.**** I have no opinion at present whether there is a correlation with area or volume.) There is often a near-low and some actual lows during this time frame in far more than 50% of the cases. If there were no effect, and a couple here have cherry-picked - and poorly did so, literally choosing two out of a long list that they thought did not meet the criteria - but you should not see an EN and a relatively low measurement far more than 50% of the time if there is zero effect. It should be completely random, and is not.
Is it an artifact of the nature of the two data sets, thus correlation without causation? Possible. But I don't think so. E.g., if EN has a negative effect on the ASI, should LN not have a positive one in some way? Yet, I found no correlation with LN at all. Not difinitive, but that finding increased my confidence there is some effect here.
Cheers