Sentences with phrase «multidecadal period»

If ENSO releases more heat than normal from the tropical Pacific over a multidecadal period, surface temperatures have to warm over that multidecadal period.

Indeed, the last thirty years likely represent the warmest multidecadal period for Europe in at least the past half millennium [Luterbacher, J., Dietrich, D., Xoplaki, E., Grosjean, M. and H. Wanner, Science, 303, 1499 - 1503, 2004], while the last decade (1995 - 2004) is likely the warmest decade, and summer 2003 the warmest summer.

CLOSING This post presented graphs and animations that showed Global SST anomalies rose and fell over the past 100 years in response to the dominant ENSO phase; that is, Global SST anomalies rose over multidecadal periods when and because El Niño events prevailed and they fell over multidecadal periods when and because La Niña events dominated.

Longer Title: Do Multidecadal Changes In The Strength And Frequency Of El Niño and La Niña Events Cause Global Sea Surface Temperature Anomalies To Rise And Fall Over Multidecadal Periods?

Again for example, during multidecadal periods when El Niño events dominate, the tropical North Atlantic trade winds would be on average weaker than «normal», there would be less evaporation, less cool subsurface waters would be drawn to the surface, and tropical North Atlantic sea surface temperatures would rise.

Someone is bound to ask, how could the global Sea Surface Temperatures rise over multidecadal periods without an increase in radiative forcing?

The author asks, «Someone is bound to ask, how could the global Sea Surface Temperatures rise over multidecadal periods without an increase in radiative forcing?»

Since Global SST anomalies respond to changes in NINO3.4 SST anomalies, this relationship implies that the strengths and frequencies of El Niño and La Niña events over multidecadal periods cause the multidecadal rises and falls in global sea surface temperatures.

The activity does vary year to year and over multidecadal periods as ocean cycles including El Nino / La Nina, multidecadal cycles in the Pacific (PDO) and Atlantic (AMO) favor some basins over others.

Not exact matches

That was another period when you had the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation chiming in together.

However, multidecadal oscillations can cover 50 - to 60 - year periods.

Most of flood periods coincided with the warm phase of the Atlantic Multidecadal Oscillation (AMO).

Using Empirical Orthogonal Function analysis, we detect multidecadal North Atlantic sea - level pressure anomalies, which are significantly linked to the NAO during the Modern period.

If you are trying to attribute warming over a short period, e.g. since 1980, detection requires that you explicitly consider the phasing of multidecadal natural internal variability during that period (e.g. AMO, PDO), not just the spectra over a long time period.

Maybe, but they are NOT a wash when you are considering a period of the order, or shorter than, the multidecadal time scales associated with these oscillations.

In addition, free - running models have produced this multidecadal cycles in their control runs (i.e. without anthropogenic forcing), although the latest batch of models have problems getting the period right.

Over the 1840 — 2007 time span, two multidecadal low temperature periods (1861 — 1919 and 1963 — 84) in Greenland coincide with periods of multiple major volcanic eruptions.

The thing is, it's not enough to look at a 10 year period in isolation and I would certainly hesitate to draw conclusions about multidecadal variability based on 10 years of data.

Periods of more frequent storm events over the two last centuries are analysed first in order to link these events with possible forcing mechanisms (North Atlantic Oscillation (NAO) and Atlantic Multidecadal Oscillation (AMO) modes) triggering the most destructive storms.

Researchers observed a natural, regular, multidecadal oscillation between periods of Southern Ocean open - sea convection, which can act a release valve for the ocean's heat, and non-convective periods.

The period from 1660 to 1760 with an approximate 60 - year cycle (1.5 cycles) looks suspiciously like the Atlantic Multidecadal Oscillation to me which then reappears in the record after 1880 for another ~ 2 cycles taking us to the present day.

«Estimating changes in global temperature since the pre-industrial period» «A reassessment of temperature variations and trends from global reanalyses and monthly surface climatological datasets» «Deducing Multidecadal Anthropogenic Global Warming Trends Using Multiple Regression Analysis» «Early onset of industrial - era warming across the oceans and continents»

They found a 60 - to 90 - year cycle in Barents and Greenland seas ice extent related to the Atlantic Multidecadal Oscillation (AMO); the AMO is a basin - wide cycle of sea surface temperature variability similar to the El Niño and La Niña cycles in the Pacific, but varying over much longer periods.

A new study using a high - resolution stalagmite record from Australia with cave sites in southern China reveal a close coupling of monsoon rainfall on both continents, with numerous synchronous pluvial and drought periods, suggesting that the tropical rain belt expanded and contracted numerous times at multidecadal to centennial scales.

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?

(A) coordinate programs at the National Oceanic and Atmospheric Administration to ensure the timely production and distribution of data and information on global, national, regional, and local climate variability and change over all time scales relevant for planning and response, including intraseasonal, interannual, decadal, and multidecadal time periods;

It is intriguing to note a shared rhythm among the following: successful synchronizations of high - frequency indices, shifts between periods of alternating character of interannual variability, and the stadium - wave's multidecadal tempo.

... 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 entire idea of higher - frequency components (the power spectrum of the Nino3.4 record peaks at ~ 5.5 a periods) producing multidecadal oscillations upon integration is mathematically impossible.

The global warming signal itself is a multidecadal feature of the climate, but just like the seasonal example above, it has been possible at times to take one period of one temperature record - surface air temperatures in most cases - and do a «January - February» job with it, thereby making the claim that temperatures are flatlining or even cooling.

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 SSMultidecadal (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 SSmultidecadal variations in NINO3.4 SST anomalies.

The near - linear rate of anthropogenic warming (predominantly from anthropogenic greenhouse gases) is shown in sources such as: «Deducing Multidecadal Anthropogenic Global Warming Trends Using Multiple Regression Analysis» «The global warming hiatus — a natural product of interactions of a secular warming trend and a multi-decadal oscillation» «The Origin and Limits of the Near Proportionality between Climate Warming and Cumulative CO2 Emissions» «Sensitivity of climate to cumulative carbon emissions due to compensation of ocean heat and carbon uptake» «Return periods of global climate fluctuations and the pause» «Using data to attribute episodes of warming and cooling in instrumental records» «The proportionality of global warming to cumulative carbon emissions» «The sensitivity of the proportionality between temperature change and cumulative CO2 emissions to ocean mixing»

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 latter, of course, is characterized by many short term peaks, dips, and flat intervals, with recent years unexceptional in this regard, but the critical issue is the extent to which multidecadal influences are competing to explain the rise during this time period.

During this period, the rate of this rise has varied on multidecadal time scales making identifying exact reasons behind upswings, such has been observed over the past few decades, difficult.

«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.

Their analysis revealed a close coupling of monsoon rainfall on both continents, with numerous synchronous pluvial and drought periods, suggesting that the tropical rain belt expanded and contracted numerous times at multidecadal to centennial scales.

We show that in the latter case, the multidecadal oscillatory mode of the smoothed AMO index with an assigned period length of 50 — 70 years can be a simple statistical artifact, a consequence of limited record length.

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.

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.

Let's take the period 1944 to 1998 — because that's the inflection points in HadCRUT4 that include the last 2 complete cooler and warmer multidecadal regimes.

At multidecadal and longer timescales, evidence from treeline, glacier, and chironomid studies suggests southwestern North America and adjacent regions experienced elevated temperatures on the order of 1 °C or less above long - term means during some or all of the medieval period (refs.

You write, in reference to it: «his choice of ocean heat uptake is based on taking a short term trend over a period in which the observed warming is markedly lower than the longer - term multidecadal value.»

It does not show an obvious signature of drought in the medieval period, as do the streamflow and DAI records, but there is a multidecadal episode of warm season drought beginning in the 12th century that would have contributed to the overall dry conditions at the time (48).

These include the Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO), both operating over a period of a few decades, and the El Niño Southern Oscillation (ENSO), which has a period of three to seven years.

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

OVERVIEW This post illustrates what many people envision after reading scientific papers about the predicted multidecadal persistence of the hiatus period — papers like Li et al. (2013) and Wyatt and Curry (2013).

Although the calculations of 18 - year rates of GMSL rise based on the different reconstruction methods disagree by as much as 2 mm mm yr - 1 before 1950 and on details of the variability (Figure 3.14), all do indicate 18 - year trends that were significantly higher than the 20th century average at certain times (1920 — 1950, 1990 — present) and lower at other periods (1910 — 1920, 1955 — 1980), likely related to multidecadal variability.The IPCC AR5 found that it is likely that a sea level rise rate comparable to that since 1993 occurred between 1920 and 1950.

My NCM is not dependent on the solar aspect as long as an alternative mechanism can be proposed for the variability of the polar high pressure cells over multidecadal time periods.

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.»