Sentences with phrase «forced decadal variability»

Not exact matches

Or does he perhaps mean that slow components, like the ocean, modulate the clouds, and the resulting cloud radiative forcing amplifies or damps the resulting interannual or decadal variability?

Reliable data on decadal variability of the Earth's radiation budget are hard to come by, but to provide some reality check I based my setting of the scaling factor between radiative forcing and the SOI / PDOI index on the tropical data of Wielecki et al 2002 (as corrected in response to Trenberth's criticism here.)

Ice - sheet responses to decadal - scale ocean forcing appear to be less important, possibly indicating that the future response of the Antarctic Ice Sheet will be governed more by long - term anthropogenic warming combined with multi-centennial natural variability than by annual or decadal climate oscillations.»

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).

[Response: The forcings have been increasing since 1850 (see here), and taking the longest period possible minimises the influence of intrinsic decadal variability in the climate system.

But questions remained concerning the degree of decadal variability, the length of the record and the balance in the models between aerosol forcing and climate sensitivity (which can't really be disentangled using this measure).

The decadal prediction involves both natural decadal variability and anthropogenic forcing.

Of course, if you have a scheme to detect the difference between intrinsic decadal variability and forced variability, we'd love to see it.

IPCC lead author Gerald Meehl stated: «In this case such claims of «no hiatus» are artifacts of questionable interpretation of decadal timescale variability and externally forced response — not problems with the data.»

«Externally Forced and Internally Generated Decadal Climate Variability Associated with the Interdecadal Pacific Oscillation.»

Models all produce natural variability, many of which show temperature flatlines over decadal timescales, and given the wide importance of natural variability over < 10 year time scales and uncertain forcings, one can absolutely not claim that this is inconsistent with current thinking about climate.

The IPCC treats natural internal variability as «noise»; we argue that it is the fundamental climate signal on decadal to century time scales, with external forcing projecting onto these modes.

The stadium wave holds promise in putting into perspective numerous observations of climate behavior, such as regional patterns of decadal variability in drought and hurricane activity, the researchers say, but a complete understanding of past climate variability and projections of future climate change requires integrating the stadium - wave signal with external climate forcing from the sun, volcanoes and anthropogenic forcing.

Where this kind of approach is useful is in assessing shorter decadal trends where variability dominates forcing.

Causes of natural variability include forcings that are external to the climate system (e.g., volcanic eruptions and aerosols and the 11 - year sunspot cycle) and internal fluctuations (weather phenomena, monsoons, El Niño / La Niña, and decadal cycles).

According to IPCC AR5, the mismatch between models and observations during both 1984 - 1998 and 1998 - 2012 may be due to «internal decadal climate variability, which sometimes enhances and sometimes counteracts the long - term externally forced trend» (Chapter 9, p. 769).

Large interdecadal to decadal changes in cloud radiative forcing, decadal to millennial variability in a wide range of factors, abrupt changes in the system state.

Identify how anthropogenic forcing and natural atmosphere - ocean variability contribute uniquely to decadal timescale changes in the width of the tropical belt.

Third, in «ENSO - Forced Variability of the Pacific Decadal Oscillation», Newman et al state in the conclusions, «The PDO is dependent upon ENSO on all timescales.»

Additional proxy records that cover the entire CE are needed to investigate decadal - to centennial - scale responses of climate to changes in radiative forcing as well as internal variability at these time scales.

What is of interest on this timescale is whether natural variability (forced and unforced) can dominate the AGW signal on decadal timescales and produce a «pause» or a «stop».

Meehl, G. A., A. Hu, and B.D. Santer, 2008: The mid-1970s climate shift in the Pacific and the relative roles of forced versus inherent decadal variability, J. Climate, in press.

US CLIVAR Decadal Predictability Working Group, 2011: Distinguishing the roles of natural and anthropogenically forced decadal climate variability: Implications for predictionDecadal Predictability Working Group, 2011: Distinguishing the roles of natural and anthropogenically forced decadal climate variability: Implications for predictiondecadal climate variability: Implications for prediction, Bull.

Define a framework to distinguish natural decadal variability from anthropogenically - forced variability and to quantify their relative magnitude.

Now forced to explain the warming hiatus, Trenberth has flipped flopped about the PDO's importance writing «One of the things emerging from several lines is that the IPCC has not paid enough attention to natural variability, on several time scales,» «especially El Niños and La Niñas, the Pacific Ocean phenomena that are not yet captured by climate models, and the longer term Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO) which have cycle lengths of about 60 years.»

Unforced variability of global temperature is great, as shown in Figure 4, but the global temperature trend on decadal and longer time scales is now determined by the larger human - made climate forcing.

[W] e diagnose annual - to - decadal variability and predictability, both unforced and forced, with an empirically determined linear model of the observed system.

Therefore, decadal hydrological prediction requires an understanding of both the externally forced component and the prediction skill of internally generated decadal hydroclimate variability.

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.

Meehl, G. A., Hu, A., Arblaster, J. M., Fasullo, J. T. & Trenberth, K. E. Externally forced and internally generated decadal climate variability associated with the Interdecadal Pacific Oscillation.

Meehl, G. A., Hu, A., Arblaster, J. M., Fasullo, J. Y. & Trenberth, K. E. Externally forced and internally generated decadal climate variability associated with the Interdecadal Pacific Oscillation.

«The figure clarifies that internal climate variability over a short decadal or 15 - year time scale is at least as important as the forced climate changes arising from greenhouse gas emissions.»

There remains some uncertainty about how much decadal variability of GMST that is attributed to AMO in some studies is actually related to forcing, notably from aerosols.

The fact that clouds may be decreasing over decadal scales does not tell us what external forcing or natural variability they may be responding to, nor does it tell us the direction or magnitude of the feedback they may be supplying.

The large variability of blocking occurrence, on both inter-annual and decadal time scales, underscores the difficulty in separating any potentially forced response from natural variability.

Held argues that decadal wiggles from internal variability complicate the estimation of TCR to GHG forcing.

9.3.1 Global Mean Response 9.3.1.1 1 % / yr CO2 increase (CMIP2) experiments 9.3.1.2 Projections of future climate from forcing scenario experiments (IS92a) 9.3.1.3 Marker scenario experiments (SRES) 9.3.2 Patterns of Future Climate Change 9.3.2.1 Summary 9.3.3 Range of Temperature Response to SRES Emission Scenarios 9.3.3.1 Implications for temperature of stabilisation of greenhouse gases 9.3.4 Factors that Contribute to the Response 9.3.4.1 Climate sensitivity 9.3.4.2 The role of climate sensitivity and ocean heat uptake 9.3.4.3 Thermohaline circulation changes 9.3.4.4 Time - scales of response 9.3.5 Changes in Variability 9.3.5.1 Intra-seasonal variability 9.3.5.2 Interannual variability 9.3.5.3 Decadal and longer time - scale variability 9.3.5.4 Summary 9.3.6 Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on changes in extremes of weather and climate 9.3.6.6 Variability 9.3.5.1 Intra-seasonal variability 9.3.5.2 Interannual variability 9.3.5.3 Decadal and longer time - scale variability 9.3.5.4 Summary 9.3.6 Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on changes in extremes of weather and climate 9.3.6.6 variability 9.3.5.2 Interannual variability 9.3.5.3 Decadal and longer time - scale variability 9.3.5.4 Summary 9.3.6 Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on changes in extremes of weather and climate 9.3.6.6 variability 9.3.5.3 Decadal and longer time - scale variability 9.3.5.4 Summary 9.3.6 Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on changes in extremes of weather and climate 9.3.6.6 variability 9.3.5.4 Summary 9.3.6 Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on changes in extremes of weather and climate 9.3.6.6 Conclusions

Meehl, G. A., Hu, A., Arblaster, J., Fasullo, J. & Trenberth, K. E. Externally forced and internally generated decadal climate variability associated with the Interdecadal Pacific Oscillation.

The reason nobody predicted it is because climatologists are interested in the forced component of clmate change, not in the short term variability (although decadal scale projections are getting to the point of being worth considering).

The quality of agreement between model simulations with 20th century forcing and observations supports the likelihood that models are adequately simulating the magnitude of natural internal variability on decadal to century time scales.

He ignores the possibility that decadal variability may be caused by external forcing such as cosmic rays which are known to cause increased rates of aerosol nucleation.

This will include researchers involved in developing prediction systems, understanding mechanisms of decadal and forced climate variability, and assessing the needs of potential users.