We have lots of new readers. This is a quick rehash.
Satellites which monitor Arctic ice (and earth’s temperature) came on line right after the PDO shift of 1977. Their period of record is coincident with a period of time dominated by positive ENSO.
From 1988-1996, most of the multi-year ice melted, and extent has generally declined during the satellite era.
It seems a safe bet that warm Pacific Ocean temperatures have led to ice loss on the Pacific side of the Arctic.
Combine that with the AMO going the warm phase in 2002 and Bob’s your Uncle.
A google image search for “enso 5 year mean” reveals a very similar image at http://digitaldiatribes.wordpress.com/2009/04/22/april-2009-update-on-the-enso-index/.
And from there i got to this very interesting article – May 2009 Sunspot Update in which the author says that if we see a low / extended solar cycle temperatures will cool.
The PDO wasn’t the only thing that shifted around 1977…
So, correct me if I’ve misunderstood, you’re suggesting that a strong negative ENSO period would reverse the downward Arctic Ice trend?
Do any records show that this negative/positive ENSO is cyclic and will a negative ENSO period likely reoccur for as long as or similar durations? When is that expected? Any guesses?
Also what effect would the negative ENSO have on the global average ice and on Antarctic snow/ice?
Chris de Freitas Ph.D., on El Nino, La Nina:
Thanks, that was an excellent video. Short. Sweet. To the point.
It doesn’t line up very well.
Up to 85, large ENSO, little melt.
1987, lower ENSO, large melt.
1992 large ENSO, large recovery.
1996 large ENSO, large recovery.
2000 low ENSO, large melt.
And when you pick another month, in this case September, the data shows the ice extent still declining in contrast to recent ENSO.
But then I think it’s pretty transparent why you picked April out of all months.
Brendan the troll hasn’t been listening very well. It’s the positive PDO cycle (in which positive ENSOs are more common) which has the warmer (than normal) SSTs in the North Pacific of which the cumulative effect would be a greater melt season. Couple that with a warm AMO (warmer waters in the North Atlantic) since 1998, and you have the perfect storm of seasonal melt. Well, the PDO switched to negative in 2007 and low and behold, we have ice recovery.
Global sea ice has being doing very little. Maybe a drop last few years as PDO peaked, but you have have a pretty good imagination to say there’s a trend.
On the other hand if all the Arctic ice migrates to the Antarctic like its been doing lately, maybe the world will flip over and Oz will be at the top not at the bottom anymore.
“But then I think it’s pretty transparent why you picked April out of all months.”
Yes, that’s the first thing that jumps out in this post — why’d he pick April? A quick check reveals that April is the only month of the year in NSIDC data for which the 2010 extent is higher than 2009, creating the cheerful little uptick painted red for visual emphasis in the graphic.
Choose any of the 11 other months, and the last data point would be down. However, the real story is that all 12 months show statistically significant declines over the full 1979-2010 period.
And submarine data indicate ice extent declining through the 1950s through 1970s, as well — when the El Nino hypothesis should imply an increase.
Actually I picked out April because the NSIDC site was down the day I made the graph, and it was the only recent graph I could find on Google images.
Nice paranoid rant though.
For extent, yes, but what about for area? I get the following slopes for Jan-Apr using NSIDC area (km^2/yr):
Unfortunately, the regression add-in is broken on my Mac Excel, and I don’t have the time to run it on my PC right now. However, I doubt that any of these area trends are significant, and if they are, the most likely one to be significant is the positive one.
At one point, someone from WUWT (I believe it was Bill Illis) said that the NSIDC data underwent some sort of adjustment in 1987…does this affect these numbers? I just have a hard time believing that NSIDC area shows no trend for those months whereas NSIDC extent and UIUC area show significant negative trends.
“Actually I picked out April because the NSIDC site was down the day I made the graph, and it was the only recent graph I could find on Google images.”
Really? Searching “NSIDC ice extent” on Google images just now turned up a single page with maybe 400 graphs, including recent ones for March, May, June and other months.
But only one time series graph, which was the one I needed.
“But only one time series graph, which was the one I needed”
Nope, the ones I mentioned are all time series graphs. As are most of the 400 or so on that page.
Stop the FUD. It was the only graph of it’s type. If you can’t have an honest discussion then please don’t post.
“Stop the FUD. It was the only graph of it’s type. If you can’t have an honest discussion then please don’t post.”
I am very honest. If you Google “NSIDC ice extent,” you should get the same hundreds of images that I’m looking at. Here’s the April graph you chose,
But from the same page of search results here is March,
all covering 1979-2010, and I’m just partway through those results.
Oh good. You found three more. You have uncovered the massive conspiracy.
Not so much a massive conspiracy, just more of the usual expected behaviour.
“Oh good. You found three more. You have uncovered the massive conspiracy.”
I found exactly what I said I found, although you called me dishonest.
Right – you said there were “hundreds”
“Right – you said there were “hundreds”
I said exactly this, which is true:
“Really? Searching “NSIDC ice extent” on Google images just now turned up a single page with maybe 400 graphs, including recent ones for March, May, June and other months.”
I take it there was increasing ice before that and you will be posting the evidence shortly, confirming the cold ENSO period increases sea ice extent. Thanks in advance.
Now NSIDC is up again how about changing April to the latest month, it’s more relevant currently 😉
Ah – you must mean October which is the highest since 2006.