Sentences with phrase «observational uncertainties»

Specific aims of the meeting will be to maximize the robustness and policy relevance of the projections provided in the presence of model error, projection uncertainty, observational uncertainties and a heterogeneous set of models.»

• A full resolution of this issue will require reducing the large observational uncertainties that currently exist.

The first paper cited notes (caveating that observational uncertainties are considerable) that models do not match observed changes in subtropical relative humidity or in global precipitation.

There has been an extensive and sometimes controversial debate in the published literature as to whether the difference between models and observations is statistically significant, once observational uncertainties and natural variability are taken into account (e.g., Douglass et al., 2008; Santer et al., 2008; Christy et al., 2010; McKitrick et al., 2010; Bengtsson and Hodges, 2011; Fu et al., 2011; Santer et al., 2012; Thorne et al., 2011).

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

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

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).

At regional scales, precipitation is not simulated as well, and the assessment remains difficult owing to observational uncertainties.

For Antarctica, large observational uncertainties result in low confidence that anthropogenic forcings have contributed to the observed warming averaged over available stations.

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.

«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.

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.

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

Given the scenario that came closest to the real world, the temperatures predicted by the model are well within the observational uncertainty.

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.

In general, comparing warming from models and obs since the mid-1800s isn't ideal, since there is large observational uncertainty prior to 1900.

Even worse: to numbers with error estimates, it adds a number without proper error estimate (the observational uncertainty for 1993 - 2003 is included, but who would claim this is an error estimation for future ice flow changes?).

Some observational uncertainty in early 20th - century trend (Sections 9.3.3.2, 9.4.1.4; Figures 9.4, 9.5).»

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

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

«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.»

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.

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.»

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.

In my observationally - based studies, observational uncertainty is substantial.

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.

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.

To characterize observational uncertainty, four atmospheric reanalyses are used as climate model surrogates and two gridded observational data sets are used as downscaling target data.

«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.

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

«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.»

So the alarm about «certain» future SLR acceleration is completely overwhelmed by real observational uncertainty.

[10] Weighting models by the likelihood of the observed TLC reflection — SST relationship at the model's best estimate (mean) of it, widening the observational uncertainty to allow for the average uncertainty of the model estimate means, is a more reasonable approach.

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.

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.

What is missing is the more quantitative information on aerosol radiative properties, geographical distributions, trends, and observational results (including uncertainties) that can be found in the IPCC AR4 Report.

These parallactic mass and radius measurements have uncertainties small enough that they may provide observational input into the stellar models themselves.

... Even in the satellite era — the best observed period in Earth's climate history — there are significant uncertainties in key observational datasets.

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.

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.

These recent studies have broken important new ground, but they largely neglect uncertainties surrounding thermal expansion (thermosteric SLR) and / or observational constraints on ocean heat uptake.

[Response: The point was made above that we are not trying to demonstrate the v1.4 or v1.2 is better, merely that there are quantitative and systematic uncertainties in the observational data set that were not reported in this paper.