Sentences with phrase «of observational uncertainty»

As in Y12, we used the point-wise difference between each pair of data sets as an indication of observational uncertainty, although this is likely to be somewhat of an underestimate of the true error.

The observed rate of warming given above is less than half of this simulated rate, and only a few simulations provide warming trends within the range of observational uncertainty.

You have to remember that the 5 year forecast is derived from a large number of individual runs each with slightly different starting conditions matching the range of the observational uncertainty in the real starting conditions.

First, what is and is not considered an extreme event needs an appropriate definition and is confronted with the problem of observational uncertainty.

Few detection studies have explicitly considered the influence of observational uncertainty on near - surface temperature changes.

We recently published a paper exploring the impact of observational uncertainty on an attribution analysis.

«Although the different estimates of OHCA (ocean heat content anomaly) produce seemingly different estimates of interannual ocean heating rate variability, these differences are all within the range of observational uncertainty.

The suggested «correction» of sunspot numbers by roughly 30 % goes far beyond the traditional estimates of observational uncertainties of sunspots.

Not exact matches

Among the advances achieved since the 2001 IPCC report is that scientists have quantified the uncertainties associated with each individual forcing mechanism through a combination of many modeling and observational studies.

But the year's worth of data that has arrived from Titan has allowed him to check his studies against new observational data and to improve his assessment of the impact of data uncertainties.

We've narrowed the uncertainty in surface warming projections by generating thousands of climate simulations that each closely match observational records for nine key climate metrics, including warming and ocean heat content.»

The form of the Jeffreys» prior depends on both the relationship of the observed variable (s) to the parameter (s) and the nature of the observational errors and other uncertainties, which determine the form of the likelihood function.

However, the recommendation to eat fruit and vegetables to prevent chronic diseases is mainly based on observational epidemiological studies, which leaves much uncertainty regarding the causal mechanism of this association.

We find that the difference between the heat balance at the top of the atmosphere and upper - ocean heat content change is not statistically significant when accounting for observational uncertainties in ocean measurements3, given transitions in instrumentation and sampling.

But since there are reasonable estimates of the real world GMT, it is a fair enough question to ask why the models have more spread than the observational uncertainty.

Here we quantify the effects of key parametric uncertainties and observational constraints on thermosteric SLR projections using an Earth system model with a dynamic three - dimensional ocean, which provides a mechanistic representation of deep ocean processes and heat uptake.

We ultimately face a question of what we trust more: our estimate of our cumulative emissions to date combined with our full knowledge of how much warming that might imply, or an estimate of how warm the system was in 2014 which is subject to error due to observational uncertainty and natural variability.

For the slope to be significant, it has to be greater than the uncertainty (which in cases of observational measurement, is the variance around the determination of the mean).

The first part of this sentence seems to demand a high level of uncertainty with respect to the later assertion, especially when one considers that the work seems to be based on 4 years of observational data, the post-2007 ice decline.

Observational uncertainties are likely to be more important for surface temperature changes averaged over small regions (Section 9.4.2) and for analyses of free atmosphere temperature changes (Section 9.4.4).

However, Hegerl et al. (2001) show that inclusion of observational sampling uncertainty has relatively little effect on detection results and that random instrumental error has even less effect.

In addition, owing to observational uncertainties and the presence of internal variability, the observational record against which models are assessed is «imperfect».

In this context even models whose predictors are far outside of the observational range can be valuable for clarifying the slope and uncertainty of the predictive relationship.

Morice, C. P., J. J. Kennedy, N. A. Rayner, and P. D. Jones, 2012: Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 dataset.

«despite increased observational uncertainty in the pre-satellite era, the trend in [Arctic sea ice extent] over this longer period [1953 — 2010] is more likely to be representative of the anthropogenically forced component.»

It also exhibits retreat of springtime snow generally greater than observational estimates, after accounting for observational uncertainty and internal variability.

It is hoped that providing these 100 realisations in a form identical to the median estimate will encourage users to explore the sensitivity of their analysis to observational uncertainty with little extra effort.

Improvements in seasonal forecasting practice arising from recent research include accurate initialization of snow and frozen soil, accounting for observational uncertainty in forecast verification, and sea - ice thickness initialization using statistical predictors available in real time.

Knutti states: «So the best we can hope for is to demonstrate that the model does not violate our theoretical understanding of the system and that it is consistent with the available data within the observational uncertainty.»

Fundamental uncertainties arise from insufficient observational evidence, disagreements over how to interpret data, and how to set the parameters of models.

It would be interesting to see Mann's analysis run with observational data properly adjusted for undercount and short - duration storms, or at a minimum considering these factors as part of the uncertainties in the analysis.

We applied the same method used in the observational analysis on general circulation model data to decrease the statistical uncertainty at the expense of an increased systematic uncertainty.

In the long term, the PAGES 2k community recommends the continued development of methods that incorporate network, observational, and chronological uncertainty into quantitative estimates of past climate variability, including approaches that allow for quantitative calibration and validation of low - frequency variability.

Irrespective of what one thinks about aerosol forcing, it would be hard to argue that the rate of net forcing increase and / or over-all radiative imbalance has actually dropped markedly in recent years, so any change in net heat uptake can only be reasonably attributed to a bit of natural variability or observational uncertainty.

Climate scientists disagree because of fundamental uncertainties arise from insufficient observational evidence, disagreements over how to interpret data, and how to set the parameters of models.»

Morice, C. P., J. J. Kennedy, N. A. Rayner, and P. D. Jones (2012), Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 dataset, J. Geophys.

The CRF curves shown in Fig. 7 and Fig. 10 of [Shaviv, 2003] have a CRF maximum near 360 m.y., while that shown in [Shaviv and Veizer, 2003] has a maximum near 320 m.y. [Shaviv, 2003] argues that such a shift of this peak is within the observational uncertainty of the position of the Norma Galactic spiral arm and would «increase the agreement» with climate data.

This study addresses the challenge by undertaking a formal detection and attribution analysis of SCE changes based on several observational datasets with different structural characteristics, in order to account for the substantial observational uncertainty.

In context of the way climate sensitivity is defined by the IPCC, uncertainty in climate sensitivity is decreasing as errors in previous observational estimates are identified and eliminated and model estimates seem to be converging more.

«In conclusion, the detection of the global temperature response to greenhouse gas increases is robust to 22 model and observational uncertainty, and methods applied to detect it.

In physical sciences, where an OLS regression model with normally distributed errors is validly used to estimate a slope parameter between two variables with observational data, errors in the regressor variable contributing a small part of the total uncertainty, it is usual to accept the uniform prior in the slope parameter (here Y) implied by the regression model.

He also presented evidence that much of the discrepancy was due to observational uncertainty, resulting from stratospheric cooling contaminating satellite measurements of tropospheric temperature (a point that's been noted by the NOAA satellite analysis team since at least 2004; see: «Contribution of stratospheric cooling to satellite - inferred tropospheric temperature trends»).

States that, instead, one has to consider additional factors such as internal variability, the tuning of the model, observational uncertainty, the temporal change in dominant processes or the uncertainty in the forcing

But, there is a way to eliminate, or at least, think differently about the uncertainty aerosols contribute to the determination of TCR with observational data.

The very high significance levels of model — observation discrepancies in LT and MT trends that were obtained in some studies (e.g., Douglass et al., 2008; McKitrick et al., 2010) thus arose to a substantial degree from using the standard error of the model ensemble mean as a measure of uncertainty, instead of the ensemble standard deviation or some other appropriate measure for uncertainty arising from internal climate variability... Nevertheless, almost all model ensemble members show a warming trend in both LT and MT larger than observational estimates (McKitrick et al., 2010; Po - Chedley and Fu, 2012; Santer et al., 2013).

«So the best we can hope for is to demonstrate that the model does not violate our theoretical understanding of the system and that it is consistent with the available data within the observational uncertainty.»

Provided that rapid losses in sea ice may be predictable, there is additional uncertainty regarding what is required in terms of an observational network and modeling system to predict such events.

They are perhaps the largest uncertainty in our understanding of climate change, owing to disagreement among climate models and observational datasets over what cloud changes have occurred during recent decades and will occur in response to global warming2, 3.

When the bottom - up approach is used to extrapolate the emissions to larger scales, uncertainty results from the inherent large temporal and spatial variations of fluxes and the limited range of observational conditions.

It should be emphasized that solving (the solvable) problems of climate prediction (or, just as important, making a realistic assessment of the ultimate limits to climate prediction set by the inherent uncertainties within the system) requires the deployment and long - term maintenance of massively expensive observational satellite and oceanographic programs.