Update on the relationship between the NINO3.4 and global SSTa

More than fifteen months ago I wrote the post “What of the Pause?”, where I tried to analyse the state of the global climate with a special focus on the interesting developments following the 2011/12 La Niña. I have also later discussed that particular time period here.

I have earlier pointed out the close connection between the SSTa in that central-eastern part of the narrow Pacific equatorial zone called “NINO3.4” and “global” SSTa over decadal time frames, how the former consistently seems to lead the latter in a tightknit relationship, firmly constraining the progression of global mean anomalies through time – flat (though with much noise) as long as the NINO3.4 signal remains strong enough to override (and/or control) all other regional signals around the globe, which most of the time it does.

I have then proceeded to show how “global warming” (or “global cooling”) only appears to come about at times when the influence of this tight relationship on the global climate is somehow offset by surface processes elsewhere, meaning outside the NINO3.4 region. This obviously doesn’t happen too often, because it would take a very powerful and persistent process to disrupt and even break the sturdy grip of the NINO3.4 region on the leash with which it controls the generally flat progression of global mean temps over time.

In fact, from 1970 to 2013 it evidently only happened three times. Which means that within these three instances of abrupt extra-NINO surface heat is contained the entire “global warming” between those years. Before, between and after, global temp anomalies obediently follow NINO3.4 in a generally (though pretty noisy) horizontal direction; no intervening gradual upward (or downward) divergence whatsoever.

With the year 2015 completed, I felt an update of this NINO3.4-global SSTa relationship was in order. Is there evidence of a new step as of late …?

My answer to this can only be: ‘It is still too early to tell.’ But interesting things have happened – and are indeed still happening – over the last two to three years, since about mid 2013:

NINO vs. gl

Figure 1.

Continue reading

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Why “GISTEMP LOTI global mean” is wrong and “UAHv6 tlt gl” is right

Ten days ago, Nick Stokes wrote a post on his “moyhu” blog where he – in his regular, guileful manner – tries his best to distract from the pretty obvious fact (pointed out in this recent post of mine) that GISS poleward of ~55 degrees of latitude, most notably in the Arctic, basically use land data only, effectively rendering their “GISTEMP LOTI global mean” product a bogus record of actual global surface temps.

Among other things, he says:

“The SST products OI V2 and ERSST, used by GISS then and now, adopted the somewhat annoying custom of entering the SST under sea ice as -1.8°C. They did this right up to the North Pole. But the N Pole does not have a climate at a steady -1.8°C. GISS treats this -1.8 as NA data and uses alternative, land-based measure. It’s true that the extrapolation required can be over long distances. But there is a basis for it – using -1.8 for climate has none, and is clearly wrong.

So is GISS “deleting data”? Of course not. No-one actually measured -1.8°C there. It is the standard freezing point of sea water. I guess that is data in a way, but it isn’t SST data measured for the Arctic Sea.”

The -1.8°C averaging bit is actually a fair and interesting point in itself, but this is what Stokes does; he finds a peripheral detail somehow related to the actual argument being made and proceeds to misrepresent its significance in an attempt to divert people’s attention from the real issue at hand. The real issue in this case of course being GISS’s (bad) habit of smearing anomaly values from a small collection of land data points all across the vast polar cap regions, over wide tracts of land (where for the main part we don’t have any data), over expansive stretches of ocean (where we do have SST data readily available) AND over complex regions affected by sea ice (where we indeed do have data (SSTs, once again) when and where there isn’t any sea ice cover, but none whatsoever when there is), all the way down to 55-60 degrees of latitude. Continue reading

“The Blob” and global SSTa since 2010

Global SSTa has really been ratcheting up now for a while. At the moment, the strong ongoing El Niño is doing most of the work, but there is no question that even this has been provided with a significantly elevated baseline from which to soar, a raised mean level seemingly establishing itself already years before the current El Niño started moving.

Well, it just so happens that this new level is higher than the old one by quite exactly 0.1 K. How can one tell?

Like this …

We noted and discussed already a year ago how the global lower troposphere has yet to respond to the conspicuous and mostly extratropical accumulation of surface heat in the NE Pacific basin starting in mid 2013.

Under the working hypothesis that this abnormal and persistent NE Pacific surface heat phenomenon (often simply nicknamed “The Blob”) is responsible for the entire 0.1K lift in the mean level of global SSTa since 2013, and positing that the lower troposphere has not yet responded to it, hence giving rise to the distinct divergence seen over the last couple of years between the “gl SSTa” and “tlt” curves, we lower the former en bloc by 0.1K from July 2013 onwards (yellow vertical line in Fig.1) and superimpose it on the latter: Continue reading

What of “The Pause”?

I have previously shown how global temperatures rose in three distinct and abrupt steps from the 70s to the 00s – one in 1979, one in 1988 and one in 1998 – and at all other times, not at all. These three steps occurred relative to the SSTa curve of the NINO3.4 region in the equatorial zone of the central-eastern part of the Pacific Ocean. Before, between and after the three steps, global temperatures appear simply obediently to follow NINO3.4 without any sign of a continued slow, but steady upward drawing away as if from a ‘steady rising background forcing’:

Warming steps

Figure 1.

My opinion on the much talked about “Pause” or “Hiatus” in ‘global warming’ still said to be going on (the considerable final, level stretch of the upper blue curve in Figure 1), is thus naturally coloured by this understanding of how global temperatures normally progress through time, as exemplified by the period from 1970 till today.

Within this perspective, the “Pause” is but one of many temperature ‘plateaus’ between sudden steps up or down (the last time it went down was back in 1964, before the ‘modern warming’). The relevant questions are: When did the last step occur? When will the next one take place? And will it go up? Or down?

At the present time, I would still maintain that the last well-established step in global temperatures happened in 1998, following directly in the wake of the mighty 1997/98 El Niño. Simply because not enough time has elapsed to be able to say anything for certain about more recent events.

But there are definitely a couple of things at work today that deserve some close attention. Continue reading