Sentences with phrase «quasi-60 year oscillation»

The records document that the Laschamp Excursion was characterized locally by (1) declination changes of ± 120 °, (2) inclination changes of more than 140 °, (3) ~ 1200 - year oscillations in both inclination and declination, (4) near 90 ° out - of - phase relationships between inclinations and declinations that produced two clockwise loops in directions and virtual geomagnetic poles (VGPs) followed by a counterclockwise loop, (5) excursional VGPs during both intervals of clockwise looping, (6) magnetic field intensities less than 10 % of normal that persisted for almost 2000 years, (7) marked similarity in excursional directions over ~ 5000 km spatial scale length, and (8) secular variation rates comparable to historic field behavior but persisting in sign for hundreds of years.

Mike's work, like that of previous award winners, is diverse, and includes pioneering and highly cited work in time series analysis (an elegant use of Thomson's multitaper spectral analysis approach to detect spatiotemporal oscillations in the climate record and methods for smoothing temporal data), decadal climate variability (the term «Atlantic Multidecadal Oscillation» or «AMO» was coined by Mike in an interview with Science's Richard Kerr about a paper he had published with Tom Delworth of GFDL showing evidence in both climate model simulations and observational data for a 50 - 70 year oscillation in the climate system; significantly Mike also published work with Kerry Emanuel in 2006 showing that the AMO concept has been overstated as regards its role in 20th century tropical Atlantic SST changes, a finding recently reaffirmed by a study published in Nature), in showing how changes in radiative forcing from volcanoes can affect ENSO, in examining the role of solar variations in explaining the pattern of the Medieval Climate Anomaly and Little Ice Age, the relationship between the climate changes of past centuries and phenomena such as Atlantic tropical cyclones and global sea level, and even a bit of work in atmospheric chemistry (an analysis of beryllium - 7 measurements).

However, if the roughly 10 - year oscillation of global temperature we have seen over the last several decades (be it due to the solar cycle or internal) holds on, we will see a considerable temperature increase during the coming years, since we are at the minimum now.

These events are crucial for the decadal frequency of the temperature at that time and produce something like a 9 year oscillation.

«The 20 - Year Oscillation in Eastern North American Temperature Records.»

Once you include the 60 year oscillation (AMO?)

I would not dispute 100 - 300 year oscillations as a possibility, but my reading of the climate records reveals no evidence for a significant role for such oscillations — or at least, no role substantial enough on a global scale to have created a discernible signal outside of changes occasioned by solar variations, volcanism, and other known entities (changes on a regional scale are a very different matter and may have involved such oscillations).

The accepted forcing series do not include these frequencies (apart from some aerosol fudges which inconsistently explain a small part of the amplitude of variation of the 61 - year oscillation), and so GCMs typically explain all of the late 20th heating with GHG forcing.

A slightly more rigourous application of the steady - state formula to account for transient behaviour should take his long wavelength temperature projection to exactly where it should sit in my view — i.e. cutting through the peaks and troughs of the 61 year oscillation.

Looking at the NOAA 50 year trend graph tells us why so many papers have identified a 60 year Oscillation and unless the entire period is considered no longer term trend can be reliable.

«one should be cautious about computations of acceleration in sea level records unless they are longer than two cycles of the oscillation or at least account for the possibility of a 60 - year oscillation in their model.

And yes, there is a 60 - year oscillation in global mean sea level.

It was shown that the detected earlier ∼ 60 - year oscillations of the amplitude and sign of SA / GCR effects on the troposphere pressure at high and middle latitudes (Veretenenko and Ogurtsov, Adv.Space Res., 2012) are closely related to the state of a cyclonic vortex forming in the polar stratosphere.

About the future, it predicts that the sun is entering in a grand minimum modulated by a quasi 60 year oscillation, with a minimum in the 2030s.

When a 60 - year oscillation 10 is modeled along with an acceleration term, the estimated acceleration in GMSL since 1900 ranges from: 0.000 -LSB--- 0.002 to 0.002] mm yr — 2 11 (90 % confidence) in the Ray and Douglas (2011) record, 0.013 [0.007 to 0.019] mm yr — 2 in the Jevrejeva et al. (2008) record, and 0.012 [0.009 to 0.015] mm yr — 2 12 (90 % confidence) in 13 the Church and White (2011) record.

And, when you have fully two cycles of a 60 year oscillation evident within the higher accuracy, directly measured data spanning the previous century, and it appears all over the place in proxy reconstructions over thousands of years as well... Then, by gum, there's a 60 year quasi-cyclic phenomenon influencing global temperatures.

The 60 - year oscillation revisited It is a well - known feature of climate change that since 1850 multiple climate datasets present a ~ 60 - year oscillation.

The GMST and AMO trends shown in Figure 6 show a low in the 1960s and high in the 1990s, suggestive of a 60 - year oscillation, as reported for the global mean sea level by Chambers et al. (2012).

I don't know why there is a 1000 year oscillation in temperatures.

Changes on a time scale of 30 years would be hard to see in most proxy records, particularly if they are preceded and followed by 20 - 50 year oscillations.

Variations between glacial and interglacial are primarily driven by the 100,000 — year oscillation of the elliptical orbit of the Sun, a major part of the Milankovitch cycle.

Here, we show that distinct, ~ 55 - to 70 - year oscillations characterized the North Atlantic ocean - atmosphere variability over the past 8,000 years.

tallbloke says: July 31, 2011 at 12:54 pm Please also explain why you now believe a 121.9 year oscillation possible, when you have previously denied the possibility of oscillations in the Sun at planetary periods shorter than this.

Richard — I interpret Bart's «We can say there is a ~ 60 year oscillation, and that its phase is such that it added to whatever else was occurring in the late 20th century» as saying that the late 20thC contained only an upswing of the oscillation and no downswing.

But a quasi-millennial cycle would not significantly interfer with the 60 - year oscillation but would determine the long forecast.

Now, we can't rule out that this recent «knee - point» is due to an other explanation (2 1/2 cycles isn't enough to rule out that the 60 - year oscillation is spurious).

We can say there is a ~ 60 year oscillation, and that its phase is such that it added to whatever else was occurring in the late 20th century.

It is not possible to state with absolute precision whether the amplitude of this 60 - year oscillation will stay the same, will increase or will decrease.

Please also explain why you now believe a 121.9 year oscillation possible, when you have previously denied the possibility of oscillations in the Sun at planetary periods shorter than this.

Then the fact that this cycle is a variable cycle and not a perfect harmonic cycle, or that it may be split in two astronomical cycles close to 20 years such as a 20 and 22 year cycles throgh various mechanisms, etc. does not change the fact that a major quasi-20 year oscillation is a astronomical oscillation, such as the ~ 10 year oscillation and the ~ 60 year oscillation and the other oscillations I am talking in my paper.

As it can be seen from the above the CET has no 60 year oscillation present, the main characteristic of the AMO.

Variations in this overturning are suspected be responsible for the apparent 65 - year oscillation in temperature around the Atlantic (AMO).

The response of temperature to the eleven year oscillations in solar irradiation associated with sunspots is almost immediate.

There is an underlying logarithmic warming trend due to increasing levels of CO2 combined with a natural 60 year oscillation of amplitude 0.14 C

As Curry alludes to, the stadium wave hypothesis posits that there is a regular, propagating, approximately 60 - year oscillation in the climate system that, among other things, affects global temperatures.

Note the both the 20 and the 60 year oscillations were at their minimum in the 1970s and in their maximum in the 2000s, and contributed at least.25 K of the about 0.5 K observed warming.

Is there a 60 - year oscillation in global mean sea level?

Although the tide gauge data are still too limited, both in time and space, to determine conclusively that there is a 60 - year oscillation in GMSL, the possibility should be considered when attempting to interpret the acceleration in the rate of global and regional mean sea level rise.

The observed pattern is compatible with a quasi 60 - year oscillation commonly observed in climate and solar records throughout the Holocene (e.g.: Chambers et al. 2012, Klyashtorin et al. 2009, Knudsen et al. 2011, Mazzarella and Scafetta 2012, Ogurtsov et al. 2002, Qian and Lu 2010, Scafetta 2010, 2012a, b, 2013a, b, c, Scafetta and Willson 2013a).

70 - 90 years oscillations in global mean temperature are correlated with corresponding oscillations in solar activity.

Further, I don't see that the 50 (+) year oscillation is discarded, as that is clearly present in the PCA for winter pattern B (see Fig. 5).

The time period (~ 150 years) is short relative to the ~ 70 year oscillations of interest.

Most likely the sensitivity is 1.5 C, since a natural 60 year oscillation is evident in the temperature data.

The model's response agrees with observations, including the long record of geopotential height variations (a function of temperature throughout the lower atmosphere), implying that these observed 10 - 12 year oscillations are likely driven, at least partially, by solar variability.

A single 1000 year simulation is inadequate for ~ 70 year oscillations.

The records document that the Laschamp Excursion was characterized locally by (1) declination changes of ± 120 °, (2) inclination changes of more than 140 °, (3) ~ 1200 - year oscillations in both inclination and declination, (4) near 90 ° out - of - phase relationships between inclinations and declinations that produced two clockwise loops in directions and virtual geomagnetic poles (VGPs) followed by a counterclockwise loop, (5) excursional VGPs during both intervals of clockwise looping, (6) magnetic field intensities less than 10 % of normal that persisted for almost 2000 years, (7) marked similarity in excursional directions over ~ 5000 km spatial scale length, and (8) secular variation rates comparable to historic field behavior but persisting in sign for hundreds of years.

The assumption that a complete quasi-60 year oscillation just happens to be within the temperature range being studied is silly.

I would be interested how you find a diurnal or even annual pattern after 3 multimonth smoothings looking at a 60 year oscillation.

During an interval when sea level is forced upward from a major low stand by a Milankovitch response acting either alone or in combination with an internally driven, higher - frequency process, ice sheets grounded on continental shelves become unstable, mass wasting accelerates, and the resulting deglaciation sets the phase of one wave in the train of 100,000 - year oscillations.

1976 S.J. Mock and III W.D. Hibler, «The 20 - Year Oscillation in Eastern North American Temperature Records.»