Sentences with phrase «for multidecadal variability»

The reason this choice matters is that this bias correction will be applied to the 21st century simulations, and the bias corrections are useless if you are merely correcting for multidecadal variability that is out of phase with the observations.

Not exact matches

Nonetheless, even if the substantial recent trend in the AO pattern is simply a product of natural multidecadal variability in North Atlantic climate, it underscores the fact that western and southern Greenland is an extremely poor place to look, from a signal vs. noise point of view, for the large - scale polar amplification signature of anthropogenic surface warming.

In that case, one needs to use some technique for separating the multidecadal variability from the long - term trend.

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).

Nonetheless, even if the substantial recent trend in the AO pattern is simply a product of natural multidecadal variability in North Atlantic climate, it underscores the fact that western and southern Greenland is an extremely poor place to look, from a signal vs. noise point of view, for the large - scale polar amplification signature of anthropogenic surface warming.

You can even argue that the 100 + years of instrumental record are still not sufficient to calibrate the proxies for multidecadal and longer variability, the relatively few years available from the satellites (which of course have calibration issues themselves) is not going to help.

As noted in that post, RealClimate defines the Atlantic Multidecadal Oscillation («AMO») as, «A multidecadal (50 - 80 year timescale) pattern of North Atlantic ocean - atmosphere variability whose existence has been argued for based on statistical analyses of observational and proxy climate data, and coupled Atmosphere - Ocean General Circulation Model («AOGCM») Multidecadal Oscillation («AMO») as, «A multidecadal (50 - 80 year timescale) pattern of North Atlantic ocean - atmosphere variability whose existence has been argued for based on statistical analyses of observational and proxy climate data, and coupled Atmosphere - Ocean General Circulation Model («AOGCM») multidecadal (50 - 80 year timescale) pattern of North Atlantic ocean - atmosphere variability whose existence has been argued for based on statistical analyses of observational and proxy climate data, and coupled Atmosphere - Ocean General Circulation Model («AOGCM») simulations.

Then when climategate triggered me to closely examine everything, notably the IPCC's attribution argument, I realized that the fingerprints were «muddy», the climate models are running too hot, the forcing data is uncertain, no account is made for multidecadal and longer internal variability, and they have no explanation for the warming 1910 - 1940, the cooling 1940 - 1976, and the hiatus since 1998.

The two studies to be discussed are: Atlantic Multidecadal Oscillation and Northern Hemisphere's climate variability (2012) and Role for Eurasian Arctic shelf sea ice in a secularly varying hemispheric climate signal during the 20th century (2013)

- ARAMATE (The reconstruction of ecosystem and climate variability in the north Atlantic region using annually resolved archives of marine and terrestrial ecosystems)- CLIM - ARCH-DATE (Integration of high resolution climate archives with archaeological and documentary evidence for the precise dating of maritime cultural and climatic events)- CLIVASH2k (Climate variability in Antarctica and Southern Hemisphere in the past 2000 years)- CoralHydro2k (Tropical ocean hydroclimate and temperature from coral archives)- Global T CFR (Global gridded temperature reconstruction method comparisons)- GMST reconstructions - Iso2k (A global synthesis of Common Era hydroclimate using water isotopes)- MULTICHRON (Constraining modeled multidecadal climate variability in the Atlantic using proxies derived from marine bivalve shells and coralline algae)- PALEOLINK (The missing link in the Past — Downscaling paleoclimatic Earth System Models)- PSR2k (Proxy Surrogate Reconstruction 2k)

(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;

Regionally, climate models underestimate the amount of sea level rise that occured, but do show reasonable agreement for interannual and multidecadal variability.

For this, we evaluated the collective behavior of higher - frequency variability of the residual signal in the fifteen indices, from which the multidecadal signal had been removed.

The BEST team found that greenhouse gases and volcanic eruptions could account for most of the observed temperature change, and suggest that the remainder of the variability is fairly consistent with the Atlantic Multidecadal Oscillation (AMO), an ocean cycle, and very little contribution from changes in solar activity (Figure 2).

«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.

The results obtained from the five Coupled Global Climate Model, version 3, (CGCM3)- driven CRCM runs are similar, suggesting that the multidecadal internal variability is not a large source of uncertainty for the Peace River basin.

Moreover, 370 years of tropical cyclone data from the Lesser Antilles (the eastern Caribbean island chain that bisects the main development region for landfalling U.S. hurricanes) show no long - term trend in either power or frequency but a 50 - to 70 - year wave pattern associated with the Atlantic Multidecadal Oscillation, a mode of natural climate variability.

Our results have important implications concerning the influence of North Atlantic sea surface temperatures on East Asian climate, and provide support for the possibility of an AMO signature on global multidecadal climate variability.»

Necessary (but not sufficient) for a credible fingerprinting attribution is to understand the fingerprints associated with natural internal variability on multidecadal and longer timescales, which is essentially ignored.

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.

b) failure of the climate models to predict a > 17 year plateau raises questions about the suitability of the climate models for detection and attribution analyses, particularly in terms of accounting adequately for multidecadal modes of climate variability...

Current GCMs inadequate for simulating natural internal variability on multidecadal time scales.

The multidecadal variability is also important for decadal predictions.

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.

For example, there is natural multidecadal variability (which has also been discussed on this blog), which is interpreted as unforced.

Quantitatively, the recurrent multidecadal internal variability, often underestimated in attribution studies, accounts for 40 % of the observed recent 50 - y warming trend.

A focus of paleo reconstructions for the past 2000 years should be detecting multidecadal variability, rather than trying to convince that the recent decade is the warmest decade, etc..

This interest in natural variability led to an irony: one of Mann's first papers, a collaboration with Jeffrey Park, provided evidence for the existence of a natural cycle, the Atlantic Multidecadal Oscillation, or AMO.

Bob Tisdale has already effectively dealt a death - blow to Michael Mann's claims, here: On Steinman et al. (2015)-- Michael Mann and Company Redefine Multidecadal Variability And Wind Up Illustrating Climate Model Failings But, this recent press release deserves some exposure for the sheer audacity of the claims made by Mann in it.