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The raw Atlantic SSTs imply 1952 was probably the equivalent of this year in the Atlantic, once you factor in that its a bit warmer globally. Dec 1952 was 20.418C in the Atlantic, Dec 2017 was 20.620C. The 1952 number is the warmest December figure in the previous warm AMO era, and consistent with the AMO being a three / six solar-cycle (33/66 year) cycle, i.e. 1895-1927 = cold, 1928-1962 = warm, 1963-1994 = cold, 1995-?? is warm. Should note, Dec 1944 was 20.348C too - pretty impressive. Dec 2016 was 20.588C, Dec 2017 2017 was 20.620C. The long-term rate of warming in December (1856-2017) implies 2017 is 1952+65 years warming.

https://www.esrl.noaa.gov/psd/data/correlation/amon.us.long.mean.data

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Correlations between Dec & MAM strongly imply Nino 3.4 will warm in MAM, but its less certain in Nino 1.2. Some kind of East-based cold-neutral look is my guess for Spring. My assumption is Nino 1.2 misses low v. the correlation given subsurface there for MAM, and Nino 3.4 v. the correlation given the subsurface there. This is what I got from weighting 13 scenarios based on existing conditions and the subsurface for Spring -

rvJt2hY.png

lBXtnuM.png

9YWaFBT.png

iSbZQWb.png

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The Atlantic/AMO did cool off a lot in January (+0.173C), not warmest on record now. Comparable/behind 2004, 2007, 2011, 2013, 2016, 2017. Couple years in the prior AMO+ cycle (particularly 1944) are very close to January 2018 in raw SSTs. February looks a lot colder than January too.

https://www.esrl.noaa.gov/psd/data/correlation/amon.us.long.mean.data

 2004   19.528   19.082   19.009   19.382   20.146   21.537   22.816   23.632   23.447   22.659   21.542   20.407
 2005   19.431   19.001   19.138   19.569   20.437   21.689   23.038   23.758   23.628   22.657   21.464   20.439
 2006   19.447   18.953   18.917   19.477   20.455   21.698   22.969   23.722   23.576   22.756   21.616   20.397
 2007   19.497   19.098   18.987   19.441   20.261   21.456   22.726   23.379   23.313   22.583   21.506   20.340
 2008   19.359   19.012   19.021   19.328   20.324   21.627   22.806   23.502   23.417   22.530   21.334   20.250
 2009   19.273   18.723   18.705   19.157   20.094   21.495   22.831   23.482   23.278   22.595   21.405   20.317
 2010   19.374   19.067   19.155   19.716   20.617   21.824   23.056   23.858   23.673   22.757   21.574   20.445
 2011   19.481   19.000   18.926   19.385   20.312   21.557   22.700   23.482   23.371   22.499   21.270   20.195
 2012   19.275   18.899   18.899   19.376   20.327   21.682   22.986   23.769   23.677   22.768   21.509   20.384
 2013   19.471   19.013   19.034   19.435   20.267   21.431   22.804   23.535   23.487   22.789   21.475   20.282
 2014   19.283   18.858   18.798   19.208   20.167   21.450   22.838   23.678   23.545   22.736   21.414   20.307
 2015   19.340   18.899   18.753   19.233   20.216   21.419   22.751   23.524   23.537   22.772   21.538   20.480
 2016   19.582   19.061   19.073   19.484   20.518   21.802   23.054   23.805   23.698   22.830   21.745   20.588
 2017   19.579   19.135   19.055   19.593   20.491   21.704   22.927   23.661   23.593   22.886   21.709   20.620
 2018   19.529  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990

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On 1/8/2018 at 9:58 PM, raindancewx said:

The raw Atlantic SSTs imply 1952 was probably the equivalent of this year in the Atlantic, once you factor in that its a bit warmer globally. Dec 1952 was 20.418C in the Atlantic, Dec 2017 was 20.620C. The 1952 number is the warmest December figure in the previous warm AMO era, and consistent with the AMO being a three / six solar-cycle (33/66 year) cycle, i.e. 1895-1927 = cold, 1928-1962 = warm, 1963-1994 = cold, 1995-?? is warm. Should note, Dec 1944 was 20.348C too - pretty impressive. Dec 2016 was 20.588C, Dec 2017 2017 was 20.620C. The long-term rate of warming in December (1856-2017) implies 2017 is 1952+65 years warming.

https://www.esrl.noaa.gov/psd/data/correlation/amon.us.long.mean.data

Is the length of the AMO cycle variable? What governs its length?

 

Also note a sign of the 11 year solar cycle is how we get torch summers every 11 years or so- 1933, 44, 55, 66, 77, 88, 99, 2010...... next one should be 2021.

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Its broadly governed by salinity and where denser waters will/won't surface, but the sun and volcanoes seem to have some influence too. Its interesting that Calbuco, Mayon and Agung are all waking up lately, and have coincided with switches from the warm to the cold AMO phase in the 1890s/1960s. Switch is coming sometime around 2024-2030 I think.

My hunch is that the small differences in solar energy mean more for sea ice extent, and volcanoes mean more for changes for total energy in the tropics. So when you blend them together...and the effect lasts for a couple years, the entire ocean cools. 

 

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The AMO doesn't seem like a good candidate to make that argument. Where do you think all that cold ice water is going when it is melting? It seems like when the natural -AMO comes, but you still have a lot of melt in the Arctic you'd have a pretty cold AMO cycle.

The other issue is, the 1980s/1990s had certainly a warmer Earth than the 1950s right? But the AMO, to use January was never above 19.2C in January from 1964-1994. It was almost every year from 1928-1963. The natural cycles just mean x region of the Earth is going to be cold or warm relative to the rest of the Earth for a while. The Earth warming doesn't change that since you have chaotic imbalances in the natural cycles, but a linear warming signal (i.e. its not chaotic).

The AMO is also more closely correlated to solar cycles than the IOD/PDO from what I've seen in doing statistical tests, might be why "solar minimum" effects seem to focus on the N. Hemisphere in areas where the AMO has the most dominance as a factor in local weather. It seems like, since we may have a grand solar minimum and are due for a major volcanic eruption in the tropics, that those features would preserve the natural flip of the cycle pretty well. Personally, since its been nearly 30-years since a major volcanic eruption in the tropics, I think we're due for 2-3 in a short period of time, whether that's in 10 years, 20 years or 50, who knows? But the models don't know either, and its why its sort of hard to take them seriously except for the signal that some level of warming will continue.

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So the NTA is neutral to negative right now, a lot because of March's Atlantic pattern change and -NAO. There is a really strong correlation to Spring North Atlantic Tripole (NTA) and Hurricane season activity. For example, 2010,2005, 1998, 1995, 1969, were all very +NTA. This year is opposite. 

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