Sentences with phrase «aerosol model simulations»

These emissions will be used as boundary conditions for chemistry / aerosol model simulations in ACC - MIP.

Not exact matches

This critical question is addressed using simulations from climate models based on projections of future emissions of greenhouse gases and aerosols.

Each model had run simulations that included anthropogenic climate influences like human - released greenhouse gases and aerosols as well as simulations run without those human influences.

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.

FMI has been involved in research project, which evaluated the simulations of long - range transport of BB aerosol by the Goddard Earth Observing System (GEOS - 5) and four other global aerosol models over the complete South African - Atlantic region using Cloud - Aerosol Lidar with Orthogonal Polarization (CALIOP) observations to find any distinguishing or common model aerosol by the Goddard Earth Observing System (GEOS - 5) and four other global aerosol models over the complete South African - Atlantic region using Cloud - Aerosol Lidar with Orthogonal Polarization (CALIOP) observations to find any distinguishing or common model aerosol models over the complete South African - Atlantic region using Cloud - Aerosol Lidar with Orthogonal Polarization (CALIOP) observations to find any distinguishing or common model Aerosol Lidar with Orthogonal Polarization (CALIOP) observations to find any distinguishing or common model biases.

In a defining document about the future of aerosol research, Pacific Northwest National Laboratory scientist Steve Ghan teamed with Brookhaven National Laboratory's Steve Schwartz, Chief Scientist for the Department of Energy's Atmospheric Science Program, to describe a disciplined process for successfully moving aerosol research from the observational stage to model simulations.

To flesh out the role of different aerosols, the PNNL and UW - led team used computer model to simulation of both marine organic matter and sulfates.

The PNNL team is currently applying the approach, which grew out of the Aerosol Climate Initiative, to other types of simulations, so that future high - resolution climate models will solve the mystery surrounding aerosol - cloud interaAerosol Climate Initiative, to other types of simulations, so that future high - resolution climate models will solve the mystery surrounding aerosol - cloud interaaerosol - cloud interactions.

The new model has a stronger physical basis and produces clouds and cloud - aerosol interactions simulations that are more realistic than those using traditional cloud parameterizations.

First computer model simulation of aerosol production done based on laboratory measurements

High - resolution simulations are being performed that resolve the local and regional variations of particulate characteristics to obtain a better understanding of important aerosol processes that need to be incorporated into larger - scale climate models.

To provide guidance for future high - resolution simulations, Dai et al. used a computationally cheaper, two - dimensional chemical transport model to systematically estimate the effects of injecting sulfur dioxide and sulfate aerosols at a range of altitudes, latitudes, and time frames for 62 separate scenarios.

To better understand what Kilimanjaro and other tropical glaciers are telling us about climate change, one ultimately ought to drive a set of tropical glacier models with GCM simulations conducted with and without anthropogenic forcing (greenhouse gases and sulfate aerosol).

These uncertainties are reflected in the model simulations of aerosol concentrations which all show similar total amounts, but have very different partitions among the different types.

But models are not tuned to the trends in surface temperature, and as Gavin noted before (at least for the GISS model), the aerosol amounts are derived from simulations using emissions data and direct effects determined by changes in concentrations.

The total warming from methane, nitrous oxide and aerosol emissions were each estimated from climate model simulations driven by historical forcing pathways for each gas, and were allocated to individual countries as described in section 2.

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.

Simulations of the more interesting and better observed twentieth century have been extensively done, and it's widely known that models can do very well with reasonable representations of aerosol and greenhouse forcing

Recently I have been looking at the climate models collected in the CMIP3 archive which have been analysed and assessed in IPCC and it is very interesting to see how the forced changes — i.e. the changes driven the external factors such as greenhouse gases, tropospheric aerosols, solar forcing and stratospheric volcanic aerosols drive the forced response in the models (which you can see by averaging out several simulations of the same model with the same forcing)-- differ from the internal variability, such as associated with variations of the North Atlantic and the ENSO etc, which you can see by looking at individual realisations of a particular model and how it differs from the ensemble mean.

We can derive the underlying trend related to external forcings from the GCMs — for each model, the underlying trend can be derived from the ensemble mean (averaging over the different phases of ENSO in each simulation), and looking at the spread in the ensemble mean trend across models gives information about the uncertainties in the model response (the «structural» uncertainty) and also about the forcing uncertainty — since models will (in practice) have slightly different realisations of the (uncertain) net forcing (principally related to aerosols).

They used climate model simulations that took into account the changes in aerosol emissions.

He chose a figure which represented model simulations of temperature responses only to greenhouse gas changes, which neglects for example the temperature response to the cooling effects of aerosols.

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.

If only GHG forcing is used, without aerosols, the surface temperature in the last decade or so is about 0.3 - 0.4 C higher than observations; adding in aerosols has a cooling effect of about 0.3 - 0.4 C (and so cancelling out a portion of the GHG warming), providing a fairly good match between the climate model simulations and the observations.

The models used the Intergovernmental Panel on Climate Change's «A1B» mid-range projected emission scenarios for ozone and aerosol precursors, independently calculated the resulting composition change, and then performed transient simulations to 2050 examining the response to projected changes in the short - lived species and to changes in both long - lived and short - lived species together.

This allowed the development and validation of more realistic simulations that replicated the aircraft measurements and thus quantified more reliably the entities that can not be obtained directly by the aircraft measurements to improve understanding and modeling of aerosol - cloud - precipitation interactions.

Additionally, changes in anthropogenic sulfate aerosol forcing have been proposed as the dominant cause of the AMV and the historical multidecadal variations in Atlantic tropical storm frequency, based on some model simulations including aerosol indirect effects.

Here we apply such a method using near surface air temperature observations over the 1851 — 2010 period, historical simulations of the response to changing greenhouse gases, aerosols and natural forcings, and simulations of future climate change under the Representative Concentration Pathways from the second generation Canadian Earth System Model (CanESM2).

I'm puzzled by your assignment of only a 30 percent probability to the proposition that «Global climate model simulations that include anthropogenic forcing (greenhouse gases and pollution aerosol) provide better agreement with historical observations in the second half of the 20th century than do simulations with only natural forcing (solar and volcanoes).»

ACCMIP will take advantage of these measurements by performing extensive evaluations of the models, especially as regards their simulations of tropospheric ozone and aerosols, both of which have substantial climate forcing that varies widely in space and time.

Global climate model simulations that include anthropogenic forcing (greenhouse gases and pollution aerosol) provide better agreement with historical observations in the second half of the 20th century than do simulations with only natural forcing (solar and volcanoes).

Climate projection — A projection of the response of the climate system to emission or concentration scenarios of greenhouse gases and aerosols, or radiative forcing scenarios, often based upon simulations by climate models.

2.10 All model simulations, whether they were forced with increased concentrations of greenhouse gases and aerosols or with increased concentrations of greenhouse gases alone, show the follow - ing features: greater surface warming of the land than of the sea in winter; a maximum surface warming in high northern latitudes in winter... All these changes are associated with identifiable physical mechanisms.

««Climate model simulations that consider only natural solar variability and volcanic aerosols since 1750 — omitting observed increases in greenhouse gases — are able to fit the observations of global temperatures only up until about 1950.»

According to model simulations, an eruption this large can pump so much sulfur dioxide gas into the stratosphere that the atmosphere does not have the capacity to oxidize all the SO2 to sulfuric acid aerosol.

However, there is not compelling evidence that anthropogenic CO2 was sufficient to influence Earth's temperatures prior to 1950, i.e. «Climate model simulations that consider only natural solar variability and volcanic aerosols since 1750 — omitting observed increases in greenhouse gases — are able to fit the observations of global temperatures only up until about 1950.»

«Here, it is sufficient to note that many of the 20CEN / A1B simulations neglect negative forcings arising from stratospheric ozone depletion, volcanic dust, and indirect aerosol effects on clouds... It is likely that omission of these negative forcings contributes to the positive bias in the model average TLT trends in Figure 6F.

«In our mor recent global model simulations the ocean heat - uptake is slower than previously estimated, the ocean uptake of carbon is weaker, feedbacks from the land system as temperature rises are stronger, cumulative emissions of greenhouse gases over the century are higher, and offsetting cooling from aerosol emissions is lower.

Based on Monte Carlo simulations and considering experimental designs with a fixed budget for the number of simulations that modeling centers can perform, the most accurate estimate of historical greenhouse gas — induced warming is obtained with a design using a combination of all - forcings, natural forcings — only, and aerosol forcing — only simulations.

Model simulations of the Asian monsoon project that the sulphate aerosols» direct effect reduces the magnitude of precipitation change compared with the case of only greenhouse gas increases (Emori et al., 1999; Roeckner et al., 1999; Lal and Singh, 2001).

The second and more interesting (to me) observation is that the simulated temperature changes are punctuated by multiple short term peaks and dips, differing from one model run to another, although the climate variables mentioned above were omitted from the simulations — there were no changes in model input in solar or aerosol forcing, and ENSO was largely eliminated by smoothing.

In CMIP5 there is no correlation between aerosol forcing and sensitivity across the ensemble, so the implication that aerosol forcing affects the climate sensitivity in such «forward» calculations is false... The spread of model climate sensitivities is completely independent of historical simulations.»

The IPCC, and the climate science community as a whole, evidently considers this observationally - based - scaling approach to be a more robust way of identifying the influence of aerosols and other inhomogeneous forcings than the almost purely climate - model - simulations - based approach used by Shindell.

Secondly, the paper relies on the simulation of the response of the CMIP5 models to aerosol, ozone and land use changes being realistic, and not overstated.

While climate contrarians like Richard Lindzen tend to treat the uncertainties associated with clouds and aerosols incorrectly, as we noted in that post, they are correct that these uncertainties preclude a precise estimate of climate sensitivity based solely on recent temperature changes and model simulations of those changes.

In the rest of this analysis I deal with the question of to what extent the model simulations used by Shindell can be regarded as providing reliable information about how the real climate system responds to forcing from aerosols, ozone and other forcing components.

The latter was a composite estimate based on modelled aerosol forcing in GCM simulations, and on their «expert assessment» of a range of − 0.68 to − 1.52 W / m ² for inverse estimates of aerosol forcing, in addition to the satellite observations derived estimates.

In a new set of simulations using an updated model accounting for dust and sea salt aerosols, Chuang et al. (2000b) obtained a forcing of 1.51 Wm - 2 for the first indirect effect from carbonaceous aerosols (0.52 and 1.16 Wm - 2 for fossil fuel and biomass burning aerosols, respectively).

At present, no transient climate simulation accounts for all aerosol - cloud interactions, so that the net aerosol effect on clouds deduced from models is not conclusive.

In the article «Global atmospheric particle formation from CERN CLOUD measurements,» sciencemag.org, 49 authors concluded «Atmospheric aerosol nucleation has been studied for over 20 years, but the difficulty of performing laboratory nucleation - rate measurements close to atmospheric conditions means that global model simulations have not been directly based on experimental data.....