Sentences with phrase «multidecadal variability using»

Assessing the Climate Impacts of the Observed Atlantic Multidecadal Variability Using the GFDL CM2.1 and NCAR CESM1 Global Coupled Models (Journal of Climate)

Ruprich - Robert, Y., F. Castruccio, R. Msadek, S. G. Yeager, T. Delworth, and G. Danabasoglu, 2016: Assessing the climate impacts of the observed Atlantic multidecadal variability using the GFDL CM2.1 and NCAR CESM1 global coupled models.

Not exact matches

Using simulations of the last millennium to understand climate variability seen in palaeo - observations: Similar variation of Iceland - Scotland overflow strength and Atlantic Multidecadal Oscillation.

Since the CMIP5 models used by the IPCC on average adequately reproduce observed global warming in the last two and a half decades of the 20th century without any contribution from multidecadal ocean variability, it follows that those models (whose mean TCR is slightly over 1.8 °C) must be substantially too sensitive.

Patterns of variability that don't match the predicted fingerprints from the examined drivers (the «residuals») can be large — especially on short - time scales, and look in most cases like the modes of internal variability that we've been used to; ENSO / PDO, the North Atlantic multidecadal oscillation etc..

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).

This study uses several independent data sources to demonstrate that century - long warming around the northeast Pacific margins, like multidecadal variability, can be primarily attributed to changes in atmospheric circulation.

- 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)

Using this ensemble, we show, firstly, that recent NH mean temperatures fall within the range of expected multidecadal variability.

«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.

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.

What was done, was to take a large number of models that could not reasonably simulate known patterns of natural behaviour (such as ENSO, the Pacific Decadal Oscillation, the Atlantic Multidecadal Oscillation), claim that such models nonetheless accurately depicted natural internal climate variability, and use the fact that these models could not replicate the warming episode from the mid seventies through the mid nineties, to argue that forcing was necessary and that the forcing must have been due to man.