Strategy # 2 bypasses the need to calibrate the climate
models against observations.
To this end, they compare the output of
the models against observations for present climate.
• Lack of formal model verification & validation, which is the norm for engineering and regulatory science • Circularity in arguments validating climate
models against observations, owing to tuning & prescribed boundary conditions • Concerns about fundamental lack of predictability in a complex nonlinear system characterized by spatio - temporal chaos with changing boundary conditions • Concerns about the epistemology of models of open, complex systems
«Its existence was predicted by the standard model of particle physics and the fact that there's — we got a glimpse of it, it looks like it may very well be there — is a real victory for that model of science where you test, you put forward conceptual models of the way the world or the universe works and test
those models against the observations and see the extent to which they can predict new observations and when they do, it gives you increased confidence in the models.
Not exact matches
Scientific
models lead to theories which can be tested
against observations.
By validating
model results
against geological
observations, the study indicates that changes in runoff, sea level and wave energy have profoundly affected the past evolution of the Great Barrier Reef not only in regard to reefs evolution but also sediment fate from source - to - sink.
They tested high - performance computational
models against known geological and geophysical
observations of the Central Anatolian Plateau, and demonstrated that a drip of lithospheric material below the surface can account for the measured elevation changes across the region.
But, says Mezzacappa, «At the end of the day, we're going to need some
observations against which we can check our
models.»
They go on to suggest that «lowering levels of TNF may be an effective strategy in improving host defense
against S. pneumoniae in older adults,» and that, «although it may be counterintuitive to limit inflammatory responses during a bacterial infection, [some existing] clinical
observations and our animal
model indicate that anti-bacterial strategies need to be tailored to the age of the host.»
In fact, the way science progresses is by conceptual
models being put forward and then testing them
against observations.
Likewise, while
models can not represent the climate system perfectly (thus the uncertainly in how much the Earth will warm for a given amount of emissions), climate simulations are checked and re-checked
against real - world
observations and are an established tool in understanding the atmosphere.
They tested the
model against regional forest mortality
observations from scientific forest plots, aerial surveys done by the U.S. Forest Service, and satellite measurements.
«Climate
models need to be validated
against observations,» she said.
The
models need to be tested
against observations, to make way for new and improved
models.
An adjustment is necessary because as climate
models are continually evaluated
against observations evidence has become emerged that the strength of their aerosol - cloud interactions are too strong (i.e. the
models» «aerosol indirect effect» is larger than inferred from
observations).
The universe is home to countless galaxies more massive than the Milky Way, which should, in theory, be bursting with star formation, but they aren't — an
observation that goes
against most current
models of the universe and star formation.
Lin, W.Y., and M.H. Zhang, 2004: Evaluation of clouds and their radiative effects simulated by the NCAR Community Atmospheric
Model against satellite
observations.
Individual components continue to be improved via systematic evaluation
against observations and
against more comprehensive
models.
Working with Tom Chase, a colleague at the institute, the researchers were comparing climate simulations from the Community Land
Model — part of a select group of global
models used in the Intergovernmental Panel on Climate Change's 2007 climate change report —
against observations.
Regarding all these hypotheticals of Earth - ssytem timescale feedbacks, etc - before results are brought forward with high confidence and reach a level of minimal academic disagreement, they should be understood physically, be exhibited in a range of
models from simple to complex, begin to emerge in
observations against natural variability, are shown to be robust to methodological choices and interpretation, and are borne out paleoclimatically.
Once calibrated, the
model can be run and evaluated
against observations not included in the calibration process.
To wit: Those who work with computer
models of climate trust them more than is warranted by the validation that can be done
against the (limited) available
observations.
And are those predictions in different cases then tested
against observations again and again to either validate those
models or generate ideas for potential improvements?
It is argued that uncertainty, differences and errors in sea ice
model forcing sets complicate the use of
models to determine the exact causes of the recently reported decline in Arctic sea ice thickness, but help in the determination of robust features if the
models are tuned appropriately
against observations.
The
model variables that are evaluated
against all sorts of
observations and measurements range from solar radiation and precipitation rates, air and sea surface temperatures, cloud properties and distributions, winds, river runoff, ocean currents, ice cover, albedos, even the maximum soil depth reached by plant roots (seriously!).
Are ocean
models so robustly based on first principles that they can be trusted without validation
against sound
observations over the time scales of interest?
The
models are gauged
against the following
observation - based datasets: Climate Prediction Center Merged Analysis of Precipitation (CMAP; Xie and Arkin, 1997) for precipitation (1980 — 1999), European Centre for Medium Range Weather Forecasts 40 - year reanalysis (ERA40; Uppala et al., 2005) for sea level pressure (1980 — 1999) and Climatic Research Unit (CRU; Jones et al., 1999) for surface temperature (1961 — 1990).
It is the average long - wave cloud forcing error derived from comparing
against observations, 20 years of hindcasts made by 26 CMIP5
models.
One could take the outcomes of different starting conditions, or use of different
model parameters, and compare them
against observations.
In general, the more complex a
model, the less it assumes, and the more easily its individual assumptions can be tested
against observations and other
models.
Improving the representation of feedbacks in climate
models, and checking them
against observations, is probably the most important area of climate
modelling research at present.
He concluded: «
Model conditioning need not be restricted to calibration of parameters against observations, but could also include more nebulous adjustment of parameters, for example, to fit expectations, maintain accepted conventions, or increase accord with other model res
Model conditioning need not be restricted to calibration of parameters
against observations, but could also include more nebulous adjustment of parameters, for example, to fit expectations, maintain accepted conventions, or increase accord with other
model res
model results.
Lee, Y.H., P.J. Adams, and D.T. Shindell, 2015: Evaluation of the global aerosol microphysical ModelE2 - TOMAS
model against satellite and ground - based
observations.
Looks like a
model is used as proof
against observations.
It also seems unfair to say that the
model - weighting approach is better because it doesn't rely on the existence of a linear relationship when you * chose * the variable to compare
against observations on the basis of that variable providing a good linear fit to your predictand.
Each climate
modeling group evaluates its own
model against certain
observations.
Errors associated with using this statistical
model to determine the global average time series is estimated by subsampling the
observations (primarily ship tracks) in the earlier period
against reanalysis data for the modern period.
• Calibrate the retrospective simulations of ice thickness from our numerical
model against the aggregate of all the observation systems by removing the mean difference between the model and the observations to create a Calibrated Model Ice Thickness Re
model against the aggregate of all the
observation systems by removing the mean difference between the
model and the observations to create a Calibrated Model Ice Thickness Re
model and the
observations to create a Calibrated
Model Ice Thickness Re
Model Ice Thickness Record.
As I said, when comparing with
observations over the short period being considered here, it makes more sense to compare with
models that include natural internal variability (i.e.: GCMs — as in the final version) than against models that do not include this and only include externally - forced changes (ie: Simple Climate Models, SCMs, — as in the SOD ver
models that include natural internal variability (i.e.: GCMs — as in the final version) than
against models that do not include this and only include externally - forced changes (ie: Simple Climate Models, SCMs, — as in the SOD ver
models that do not include this and only include externally - forced changes (ie: Simple Climate
Models, SCMs, — as in the SOD ver
Models, SCMs, — as in the SOD version).
How hard would it be to just collect source code for the various
models, and test them
against different input parameters, as well as newer
observations, and see which physics is likely to be more realistic?
Gray's crusade
against global warming «hysteria» began in the early 1990s, when he saw enormous sums of federal research money going toward computer
modeling rather than his kind of science, the old - fashioned stuff based on direct
observation.
None of current
models have a sufficient number of runs to overcome chaotic uncertainty and therefore can not be validated
against observations.
This was established on the systematic comparison between
models» predictions with actual
observations obtained over almost one solar cycle (1998 — 2007) at four European ionospheric locations (Athens, Chilton, Juliusruh, and Rome) and on the comparison of the
models» performance
against two standard prediction strategies, the median - and the persistence - based predictions.
Note that the Russians validated their
model tuning
against observations — I think this is a major breakthrough.
Not all that is performed in
models is for the purpose of direct comparison
against observations.
Likewise, to properly represent internal variability, the full
model ensemble spread must be used in a comparison
against the
observations, as is well known from ensemble weather forecasting (e.g., Raftery et al., 2005).
Personally I don't expect the IPCC to find science that compares
observations against every single
model projection ever made, whereas you seem to think they ought to.
And if they have the millions of dollars to make a
model why wouldn't we expect them to test THAT
model (and all of its cohort)
against the
observations and publish those results?
Models, like all scientific theory, have to be tested
against real - world
observations.
Model forecasts are verified against model control simulations (perfect model experiments), thus overcoming to some extent issues of uncertainties in the observations and / or model parameterizat
Model forecasts are verified
against model control simulations (perfect model experiments), thus overcoming to some extent issues of uncertainties in the observations and / or model parameterizat
model control simulations (perfect
model experiments), thus overcoming to some extent issues of uncertainties in the observations and / or model parameterizat
model experiments), thus overcoming to some extent issues of uncertainties in the
observations and / or
model parameterizat
model parameterizations.