Sentences with phrase «compared model simulations»

Attribution scientists compare model simulations that include both manmade and natural factors against simulations that include only natural factors.

Not exact matches

«Therefore, we are always trying to compare the simulations with real phenomena to improve the models.

She then created a computer model of wind patterns and compared the simulations to the data to find out what information she still needed.

When they compared the 2 - D results against those of the 3 - D simulations, they found that the 2 - D model underestimated how quickly the flood wave moved across land and overestimated the time at which the maximum flood occurred.

Unfortunately, current simulation models, which combine global climate models with aerosol transport models, consistently underestimate the amount of these aerosols in the Arctic compared to actual measurements during the spring and winter seasons, making it difficult to accurately assess the impact of these substances on the climate.

They then compared their yearly September ozone measurements with model simulations that predict ozone levels based on the amount of chlorine that scientists have estimated to be present in the atmosphere from year to year.

For the RCP8.5 projections, which represents stronger increases in greenhouse gas concentrations than RCP4.5, there was a striking level of consistency in the magnitude of change in AR frequency — all models showed an approximate doubling of the number of future ARs compared to the simulations for 1980 — 2005.

«And when we compare the models to the data, there's a stunning similarity between the star - forming showers we observe and ones that occur in simulations.

Changes in fall - winter rainfall from observations (top panel) as compared to model simulation of the past century (middle panel), and a model projection of the middle of the 21st century.

Computer simulation is similar, it's reductionist; you've got these parts, you want to see how they interact, so you build a model and compare it to the real world.

Until now this type of analysis has been a tedious process that involves comparing actual images of lenses with a large number of computer simulations of mathematical lensing models.

However, unlike the climate model simulations, the new precipitation reconstruction does not show an increase of wet and dry anomalies in the twentieth century compared to the natural variations of the past millennium.

In a unique study set - up, the scientists first compared simulation results from a large ensemble of wheat crop growth models with experimental data, including artificial heating experiments and multi-locational field trials.

To better understand the physical mechanisms of rapid ocean adjustment, the data was compared with a climate model simulation which covers the same period.

A particular emphasis of Hayward's research is on combining hydrodynamic simulations of galaxy formation with radiative transfer calculations to create «forward models» of observable quantities, such as images and spectra, that can be directly compared with data from telescopes such as the Hubble Space Telescope.

Running future simulations in climate models with present - day emissions, Cai and his colleagues find 73 per cent increase in extreme La Niña events in the twenty - first century when compared to the twentieth.

It is a pity that they stopped the simulation before the CO2 decrease (111,000 - 106,000 BP), to see what the model produces for further cooling, compared to reality...

To understand the role of human - induced climate change in these new records they compare simulations of the Earth's climate from nine different state - of - the - art climate models and the very large ensemble of climate simulations provided by CPDN volunteers for the weather@home ANZ experiments for the world with and without human - induced climate change.

They compared the empirical data to the model simulations of the MJO, where much of the MJO processes are currently represented with parameterizations, a way to express complex climate systems in a computationally efficient way.

Detailed simulations of blend models composed of an eclipsing binary plus a third star diluting the eclipses were compared with the observed light curve and used to derive the properties of the three components.

They compared these methods against a detailed model estimate to see how they measured up against the benchmark simulations.

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.

Two groups of students, those who used real equipment and those who used a computer simulation that explicitly modeled electron flow, were compared in terms of their mastery of physics concepts and skills with real equipment.

Compared to the previous Ridgeline model, the coefficient of drag x area (CdA) is reduced 15 percent, as determined by CFD simulations.

When looking for SYSTEMATIC deviations between data and model simulations, one calculates the mean and the standard deviation of the mean for each and compares.

«By comparing the response of clouds and water vapor to ENSO forcing in nature with that in AMIP simulations by some leading climate models, an earlier evaluation of tropical cloud and water vapor feedbacks has revealed two common biases in the models: (1) an underestimate of the strength of the negative cloud albedo feedback and (2) an overestimate of the positive feedback from the greenhouse effect of water vapor.

With error bars provided, we can use the PIOMAS ice volume time series as a proxy record for reality and compare it against sea - ice simulations in global climate models.

The authors compared recently constructed temperature data sets from Antarctica, based on data from ice cores and ground weather stations, to 20th century simulations from computer models used by scientists to simulate global climate.

Decadal hindcast simulations of Arctic Ocean sea ice thickness made by a modern dynamic - thermodynamic sea ice model and forced independently by both the ERA - 40 and NCEP / NCAR reanalysis data sets are compared for the first time.

In a related paper, Santer et al compare the surface / lower - troposphere coupled tropical variability at different timescales in the data and in model simulations performed for the new IPCC assessment.

As a check of this, one could comparing the climate model simulations of temperature change using the historical forcing runs with the temperature change produced by the same models under CO2 - only forcing runs * at times of equivalent total forcing change *.

I did so, and in so doing pointed out a number of problems in the M&N paper (comparing the ensemble mean of the GCM simulations with a single realisation from the real world, and ignoring the fact that the single GCM realisations showed very similar levels of «contamination», misunderstandings of the relationships between model versions, continued use of a flawed experimental design etc.).

Vecchi et al. compared the observed trend in the Walker circulation between 1861 and 1992 to that yielded by simulations from the GFDL CM2 general circulation model, run with and without anthropogenic forcing.

Julie Hargreaves has a new paper out on this precise question and shows that the early model simulations had substantial skill compared to any naive model.

A detailed reanalysis is presented of a «Bayesian» climate parameter study (Forest et al., 2006) that estimates climate sensitivity (ECS) jointly with effective ocean diffusivity and aerosol forcing, using optimal fingerprints to compare multi-decadal observations with simulations by the MIT 2D climate model at varying settings of the three climate parameters.

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0628.1 In our discussion exploring the (very minor) differences in results when using different datasets we said: - «Dataset creation approaches that infill missing data areas may give overconfidence to climate changes in regions where there are no direct measurements, when compared with model simulations that have data in those regions.»

It is a pity that they stopped the simulation before the CO2 decrease (111,000 - 106,000 BP), to see what the model produces for further cooling, compared to reality...

Interestingly, the long - term variations indicated by the model simulations compared remarkably well with those documented by the tree - ring reconstruction, showing no obvious sign of the potential biases in the estimated low - frequency temperature variations that have been the focus of much previous work (see e.g. this previous RealClimate review).

Forest et al. 2006 compares observations of multiple surface, upper air and deep - ocean temperature changes with simulations thereof by the MIT 2D climate model run at many climate parameter settings.

The aim of increasing resolution in AGCMs is generally to improve the simulation of surface climatology compared to coarser resolution models (Cubash et al., 1995).

Both periods had a substantially different climate compared to the present, and there is relatively good information from data synthesis and model simulation experiments (Braconnot et al., 2004; Cane et al., 2006).

Judith, I think falling best estimates for aerosol offsets in the SOD (compared to AR4) and simultaneous continued use of earlier (larger) aerosol offsets in the climate model simulations borders on daft.

The most popular observationally - constrained method of estimating climate sensitivity involves comparing data whose relation to S is too complex to permit direct estimation, such as temperatures over a spatio - temporal grid, with simulations thereof by a simplified climate model that has adjustable parameters for setting S and other key climate properties.

We can therefore again compare the Scenario A2 multi-model global surface warming projections to the observed warming, in this case since 2000, when the AR4 model simulations began (Figure 9).

In model's simulations, the drop in central pressure is relatively more in the months of May, June, September and October during 2071 — 2100 compared with that during 1961 — 1990.

However, model physics process representations that are supposed to account for the eddy moisture transport effects on convection significantly underestimate them compared to simulations that explicitly resolved eddy moisture transport without using convective representations.

These reconstructions are highly relevant when comparing ocean data with model simulations of global and regional climate change.

I saw a poster a at a meeting last year that compared a simulation with prescribed SST to another with a slab ocean model (SOM) and the results were very striking, so I started thinking that I need to explore this type of modelling more.

> A major advance of this assessment of climate change projections compared with the TAR is the large number of simulations available from a broader range of models.

In your blog post you mentioned a lot of recently published papers that show model simulations don't do well compared to observations even in hindcast.