Sentences with phrase «of multidecadal»

Analyses of global climate from measurements dating back to the nineteenth century show an «Atlantic Multidecadal Oscillation» (AMO) as a leading large - scale pattern of multidecadal variability in surface temperature.

IPCC's warming rate of 0.2 deg C / decade is not the climate signal as it includes the warming rate due to the warming phase of the multidecadal oscillation.

IPCC's climate sensitivity of about 3 deg C is incorrect because it includes the warming rate due to the warming phase of the multidecadal oscillation.

Whereas each model demonstrates some sort of multidecadal variability (which may or may not be of a reasonable amplitude or associated with the appropriate mechanisms), the ensemble averaging process filters out the simulated natural internal variability since there is no temporal synchronization in the simulated chaotic internal oscillations among the different ensemble members.

And finally, attribution studies can't simply rely on model simulations, since model simulations (even if they capture the correct spectrum of variability) won't match the observed realization of the multidecadal modes in terms of timing.

The modes of natural internal variability of greatest relevance are the Atlantic modes (AMO, NAO) and the Pacific models (PDO, often referred to as IPO) of multidecadal climate variability, with nominal time scales of 60 - 70 + years.

As discussed in our posting above, Emanuel's analyses also cast doubt on the proposition that the recent Atlantic basin trends can be dismissed as simply part of multidecadal cycle alone.

«Accompanied by significant peaks at 60.2 and 73 years, the continuously periodicities around 49 — 114 years in our regional temperature reconstruction might tentatively be related to PDO, Atlantic Multidecadal Oscillation... as well as solar activity... The AMO was an important driver of multidecadal variations in summer climate not only in North America and western Europebut also in the East Asia... The 60.2 - year peak associated with AMO demonstrated that multidecadal variations in late summer temperature in the NWSP NWSP [northwestern Sichuan Plateau, China] might be controlled by AMO.»

The presence of multidecadal internal variability superimposed on the secular trend gives the appearance of accelerated warming and cooling episodes at roughly regular intervals.

This result is important because the statistical significance of this multidecadal oscillation in the long records has not been established previously either in Greenland ice core data (17) or in a previous analysis of CET (18).

Third: There was no cooling in the 1920s; in fact that was the start of a multidecadal warming trend that lasted until just after World War II (followed by a brief cooling trend, possibly due to increased aerosols dimming incoming sunlight together with some pretty big volcanic eruptions which did the same thing).

On the time - varying trend in global - mean surface temperature ``... we showed that the rapidity of the warming in the late twentieth century was a result of concurrence of a secular warming trend and the warming phase of a multidecadal (~ 65 - year period) oscillatory variation and we estimated the contribution of the former to be about 0.08 deg C per decade since ~ 1980.»

«Internal and external forcing of multidecadal Atlantic climate variability over the past 1,200 years» Authors: Jianglin Wang1, Bao Yang1, Fredrik Charpentier Ljungqvist2, 3, Jürg Luterbacher4, 5, Timothy J. Osborn6, Keith R. Briffa6, Eduardo Zorita7, Available at — https://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2962.html Nature Geoscience (2017) doi: 10.1038 / ngeo2962

Instead, the find the historical records dominated by periods of multidecadal variability.

«An analysis of multidecadal modulation of flood risk is achieved using the interdecadal Pacific Oscillation (IPO) index.

Although the secular trend is mild (~ 0.25 K / century), there is nearly double that trend in the January data, which is poorly correlated with the yearly averages (R ^ 2 = 0.27) and shows persistently rising bottoms of multidecadal cycles since the latter half of the 18th century.

However, I am convinced that if Dr. Spencer did a regression against ALL available variables including CO2 (instead of «cherry picking» only three), then his regression would put CO2 in its proper place as driving the very long term trend while the AMO would assume its proper place in driving much of the multidecadal variation and boosting the recent warming.

Paul Vaughan says: July 26, 2011 at 7:06 am so spatial aggregation criteria alone can be responsible for observed amplitudes of multidecadal variation.

Given that the past 30 — 50 years is a relatively short period for evaluating long - term trends, the SST trends themselves could be viewed as a manifestation of large - scale modes of multidecadal Pacific variability (e.g. Zhang et al. 1997; Deser et al. 2004) or as part of the century scale positive SST trends associated with climate change (e.g. Deser et al. 2010); it is likely that both multidecadal climate variability and climate change have contributed to the SST trend pattern evident in Fig. 9 and used to force the model.

The terrestrial surface is not of uniform heat capacity, so spatial aggregation criteria alone can be responsible for observed amplitudes of multidecadal variation.

We note however that we have not separated the relative roles of multidecadal variability and externally forced climate change, nor fully discriminated the relative roles of tropical SSTs and extratropical SSTs and sea ice in explaining the circulation trends at high Southern latitudes.

I emphasize the importance of multidecadal oscillations (e.g. AMO, PDO) and allow for the possibility of longer scale oscillations.

In Wu et al. (2007) we showed that the rapidity of the warming in the late twentieth century was a result of concurrence of a secular warming trend and the warming phase of a multidecadal (~ 65 - year period) oscillatory variation and we estimated the contribution of the former to be about 0.08 C per decade since ~ 1980.

The existence of the multidecadal variability makes climate change detection a challenge, since Global Warming evolves on a similar timescale.

Recent accelerated warming of the Arctic results from a positive reinforcement of the linear warming trend (due to an increasing concentration of greenhouse gases and other possible forcings) by the warming phase of the multidecadal climate variability (due to fluctuations of the Atlantic Ocean circulation).»

A lot of work was devoted during the last years to understand the dynamics of the multidecadal variability, and external as well as internal mechanisms were proposed.

For detailed evidence with graphs see Relationship of Multidecadal Global Temperatures to Multidecadal Ocean Oscillations Ch.

Together they create a pattern of multidecadal Pacific variability.

Parker, D. E., P. Jones, T. C. Peterson, and J. Kennedy, 2009: Comment on Unresolved issues with the assessment of multidecadal global land surface temperature trends.

«Bias might be introduced in cases where the spatial coverage is not uniform (e.g., of the 24 original chronologies with data back to 1500, half are concentrated in eastern Siberia) but this can be reduced by prior averaging of the chronologies into regional series (as was done in the previous section)... Eight different methods have been used... They produce very similar results for the post-1700 period... They exhibit fairly dramatic differences, however, in the magnitude of multidecadal variability prior to 1700... highlighting the sensitivity of the reconstruction to the methodology used, once the number of regions with data, and the reliability of each regional reconstruction, begin to decrease.

In Wu et al. (2007) we showed that the rapidity of the warming in the late twentieth century was a result of concurrence of a secular warming trend and the warming phase of a multidecadal (~ 65 - year period) oscillatory variation and we estimated the contribution of the former [secular warming] to be about 0.08 °C per decade since ~ 1980.

The authors conclude: «Ultimately, the consistency of our results suggests an exceptionally high risk of a multidecadal megadrought occurring over the Central Plains and Southwest regions during the late 21st century, a level of aridity exceeding even the persistent megadroughts that characterised the Medieval era.»

Again, the peaks in the «GISS Multidecadal (31 - year span) Changes In Global SST anomaly» data represent the periods with the greatest linear trends, and, as shown in Figure 7, they lag the peaks of the multidecadal variations in NINO3.4 SST anomalies.

Claims of multidecadal «stadium wave» patterns of variation across multiple climate indices are also shown to likely be an artifact of this flawed procedure for isolating putative climate oscillations.

The evolution of the multidecadal oscillations (e.g. where you are at on the stadium wave wheel) 2.

The PDO, therefore, can not be the cause of the multidecadal rises and falls in global SST anomalies.

... we showed that the rapidity of the warming in the late twentieth century was a result of concurrence of a secular warming trend and the warming phase of a multidecadal (~ 65 - year period) oscillatory variation and we estimated the contribution of the former to be about 0.08 deg C per decade since ~ 1980.

THE ANIMATION OF MULTIDECADAL CHANGES IN SST ANOMALIES The Goddard Institute of Space Studies (GISS) Global Map - Making webpage allows users to create maps of global SST anomalies and maps of the changes in global SST anomalies (based on local linear trends) over user - specified time intervals.

2) D'Aleo, J. and Easterbrook, D.J., 2011, Relationship of multidecadal global temperatures to multidecadal oceanic oscillations: in Easterbrook, D.J., ed., Evidence - Based Climate Science, Elsevier Inc., p. 161 - 184.

Or is the recent warming trend of 0.2 deg C per decade for the period 1970 - 2000 is just the warming phase of the multidecadal oscillation similar to that for the period 1910 - 1940?

al. do, or do you believe they are part of the multidecadal PDO and are likely to last a long time, as Kosaka and Xie do.

What we can say is that the three curves in the figure to the upper left give one plausible account of multidecadal climate, MUL, since 1850.

1) Unless I am misunderstanding you are not using a physical model of multidecadal cycles.

However if one chooses to interpret the last 50 years of MRES as somehow part of multidecadal climate, namely as extra upticks around 1970 and 2000 from the baseline set by 1850 - 1950, as I proposed in the first sentence of the conclusion, «plus a miniscule amount from MRES after 1950,» then I would think around a mK is fair when those upticks are included as part of «modern multidecadal climate.»

Have a competition to produce independent models of the natural and artificial components of multidecadal HadCRUT3 and evaluate them according to (a) how reasonable each is separately, and (b) how well their combination fits the data.

Except that we know from the paper itself that the surface phenomena aren't causing more than 14 % of the multidecadal change in LOD.

Because even if we'd never heard of CO2 we'd still have this separation of multidecadal climate between Figures 1 and 2 into an oscillating component and a rising component, whose upward - curvature has continually been getting steeper and shows no sign of abruptly turning into a downward curvature.

I'm fitting a model of multidecadal climate, namely SAW+AGW, to HadCRUT3.

I am very grateful to Mike Rossander for proposing an alternative description of multidecadal climate, which I've been asking for ever since I posted on December 4.

Girma,» about 0.12 deg C per decade is due to the warming phase of the multidecadal oscillation» === is EVEN BIGGER FRAUD!!!