Sentences with phrase «on observational estimates»

«Dessler's study is just showing that the observational estimates of ECS are plausibly estimates from the bottom of the spread and that the difference between observational and ensemble based estimates is plausibly the effects of internal variability on the observational estimates.»

I note that the key Sulphate aerosols component was derived using the HadCM3 AOGCM, rather than being based directly on observational estimates.

TCR is not that uncertain and a growing body of research focused on observational estimates of TCR shows is isn't likely larger than 1.2 - 1.4 C, indicating transient climate feedbacks are small.

Not exact matches

The team compared the scattering coefficient obtained by their approach with the scattering coefficient measured on board the aircraft and found good agreement between the estimated and measured scattering coefficients for a wide range of observational conditions.

[11] Asteroseismic analyses that incorporate the tight observational constraints on the stellar parameters for α Cen A and / or B have yielded age estimates of 7000484999999999999 ♠ 4.85 ± 0.5 Gyr, [7] 7000500000000000000 ♠ 5.0 ± 0.5 Gyr, [27] 5.2 — 7.1 Gyr, [28] 6.4 Gyr, [29] and 7000652000000000000 ♠ 6.52 ± 0.3 Gyr.

The visualization covers the period June 2005 to December 2007 and is based on a synthesis of a numerical model with observational data, created by a NASA project called Estimating the Circulation and Climate of the Ocean, or ECCO for short.

On the other hand, the observational estimates for charter schools that contribute to the lottery study are larger than the observational estimates for other charter schools (though the latter are still positive and significantly different from 0).

In an effort to gauge the external validity of our lottery estimates, we computed observational estimates that rely solely on statistical controls, with separate effects for schools in and out of the lottery sample.

In the end, what can be more fairly and appropriately asserted from this research report is that the Marzano model is indeed correlated with value - added estimates, and their correlation coefficients fall right in line with all other correlation coefficients evidenced via other current studies on this topic, again, whereby researchers have correlated multiple observational models with multiple value - added estimates.

However, what we have seen since 2009, when states began to adopt what were then (and in many ways still are) viewed as America's «new and improved» or «strengthened» teacher evaluation systems, is that for 70 % of America's teachers, these teacher evaluation systems are still based only on the observational indicators being used prior, because for only 30 % of America's teachers are value - added estimates calculable.

Evaluations in years one and two (1) assessed preschool quality using two observational measures, (2) measured children's gains in receptive vocabulary, literacy, math and executive functions, and (3) compared gains of SPP attendees to those of a non-equivalent comparison group to estimate SPP impacts on children's learning and development.

She used R (i.e., a free software environment for statistical computing and graphics) to simulate correlation scatterplots (see Figures below) to illustrate three unique situations: (1) a simulation where there are two indicators (e.g., teacher value - added and observational estimates plotted on the x and y axes) that have a correlation of r = 0.28 (the highest correlation coefficient at issue in the aforementioned post); (2) a simulation exploring the impact of negative bias and a moderate correlation on a group of teachers; and (3) another simulation with two indicators that have a non-linear relationship possibly induced or caused by bias.

In short, irrespective of what observational dataset was used — it's likely that an estimate of forced response made in 2014 would be biased cold, which on its own would translate to an overestimate of the available budget of about 40GtC.

I agree that the models tend to show less decadal ocean variability than observed (given the obvious caveats on the observational side), but absolutely disagree that this implies that longer term estimates are off.

Whether you are gullible enough to accept the figures as accurate depends on how much credibility you put in the multitude of observational measurements taken by different methods over many decades by diverse groups of researchers that form a strong consilience of mutually supporting evidence for the validity of the estimates and the possible errors.

Observational errors on any one annual mean temperature anomaly estimate are around 0.1 deg C, and the errors from the linear fits are given in the text.

These estimates are generally model - based because of difficulties in obtaining reliable internal variability estimates from the observational record on the spatial and temporal scales considered in detection studies.

Studies surveyed Millar, R. et al. (2017) Emission budgets and pathways consistent with limiting warming to 1.5 C, Nature Geophysics, doi: 10.1038 / ngeo3031 Matthews, H.D., et al. (2017) Estimating Carbon Budgets for Ambitious Climate Targets, Current Climate Change Reports, doi: 10.1007 / s40641 -017-0055-0 Goodwin, P., et al. (2018) Pathways to 1.5 C and 2C warming based on observational and geological constraints, Nature Geophysics, doi: 10.1038 / s41561 -017-0054-8 Schurer, A.P., et al. (2018) Interpretations of the Paris climate target, Nature Geophysics, doi: 10.1038 / s41561 -018-0086-8 Tokarska, K., and Gillett, N. (2018) Cumulative carbon emissions budgets consistent with 1.5 C global warming, Nature Climate Change, doi: 10.1038 / s41558 -018-0118-9 Millar, R., and Friedlingstein, P. (2018) The utility of the historical record for assessing the transient climate response to cumulative emissions, Philosophical Transactions of the Royal Society A, doi: 10.1098 / rsta.2016.0449 Lowe, J.A., and Bernie, D. (2018) The impact of Earth system feedbacks on carbon budgets and climate response, Philosophical Transactions of the Royal Society A, doi: 10.1098 / rsta.2017.0263 Rogelj, J., et al. (2018) Scenarios towards limiting global mean temperature increase below 1.5 C, Nature Climate Change, doi: 10.1038 / s41558 -018-0091-3 Kriegler, E., et al. (2018) Pathways limiting warming to 1.5 °C: A tale of turning around in no time, Philosophical Transactions of the Royal Society A, doi: 10.1098 / rsta.2016.0457

Carbon budgets have been estimated by a number of different methods, including complex ESMs (shown in yellow), simple climate models employed by Integrated Assessment Models (IAMs, shown in red), and by using observational data on emissions and warming through present to «constrain» the ESM results (shown in blue).

As an extension, systematic observational errors could perhaps be corrected as part of the regression by estimating a constant shift to apply to each thermometer (treating changes in technology as creating a new thermometer on the same site), though this may make the problem too large.

«Lewis & Crok perform their own evaluation of climate sensitivity, placing more weight on studies using «observational data» than estimates of climate sensitivity based on climate model analysis.»

Depending on the observational data set, the GMST trend over 1998 — 2012 is estimated to be around one - third to one - half of the trend over 1951 — 2012 (Section 2.4.3, Table 2.7; Box 9.2 Figure 1a, c).

Based on our assumptions of observational values, we conclude the AR4 model - mean or — best estimate ‖ of the SR (1.38 ± 0.08) is significantly different from the SRs determined by observations as described above.

The fact that our pf ′ values (even for 30 - year TLT trends) are sensitive to the addition of a single year of observational data indicates the dangers of ignoring the effects of interannual variability on signal estimates, as was done, for example, in Douglass et al. [2007].

Carrick «Keep in mind the estimates for the half - life of CO2 emissions is on the order 800 years (based on correlational studies)» niclewis September 24, 2014 at 3:00 pm I'm not sure that is supported by good observational evidence.

An independent estimate of global - mean evaporation provides additional support, but critical assumptions on relative humidity and the air - sea temperature difference changes are made that do not have adequate observational basis and are inconsistent with climate models.»

There are also a substantial number of observational climate sensitivity estimates below 1 C. e.g. Lindzen & Choi (2009) at 0.5 C. See my comment on apparent bimodal distribution of climate sensitivity estimates.

Climate scenarios based on model estimates of future climate can be constructed either by adopting the direct model outputs or by combining model estimates of the changed climate with observational climate data.

Attempts to understand trans - basin AMOC variability over the modern observational record traditionally have had to rely on indirect estimates assessed from hydrography.

These data provide an important observational constraint on estimates of radiative forcing and temperature response.

The traditional global mean radiative forcing provides no information about this regional structure, so many researchers have begun to present estimates of radiative forcing on a regional scale as derived from models or observational campaigns.

To better assess confidence in the different model estimates of climate sensitivity, two kinds of observational tests are available: tests related to the global climate response associated with specified external forcings (discussed in Chapters 6, 9 and 10; Box 10.2) and tests focused on the simulation of key feedback processes.

The [climate models] overestimate future warming by 1.7 — 2 times relative to an estimate based on the best observational evidence.

, which are in fact the excess of AFari + aci over RFari, need adjusting (scaling down by (0.73 − 0.4) / (0.9 − 0.4), all years) to obtain a forcing dataset based on a purely observational estimate of aerosol AF rather than the IPCC's composite estimate.

[8] Brient and Schneider justify using a divergence measure based on the similarity of the model and observational estimate PDFs on the basis that «they are estimated from time series of the same length L so that their sampling variability can be expected to be equal if a [statistical] model is adequate».

Although there exist observational estimates of the SAMOC, the decadal and multi-decadal variability of the SAMOC and its influence on climate and weather can not be assessed due to its short temporal record.

The 0C - 10C range for 2xCO2 climate sensitivity encompasses ALL the published estimates I have seen, from the Spencer and Lindzen lower end of 0.6 C (from CERES and ERBE satellite observations) and the Forster and Gregory range of 0.9 C to 3.7 C (based on «purely observational evidence» — see earlier thread) to IPCC's range of 2.0 C to 4.5 C (from model simulations based largely on theoretical deliberations rather than physical observations).

However, it has been absent in almost all observational estimates on decadal timescales — upon which non-climatic artefacts project most strongly.