Sentences with phrase «aerosol radiative»

Fridlind, A.M., and M.Z. Jacobson, 2003: Point and column aerosol radiative closure during ACE 1: Effects of particle shape and size.

The complexity of radiative - dynamical response forced volcanic impacts suggests that it is important to calculate aerosol radiative effects interactively within the model rather than prescribe them.

When partnered with cloud remote sensing observations the radiation measurements and retrievals allow the characterization of cloud and aerosol radiative effects at the surface, which is essential in order to quantify the amount of radiative energy available at the surface to interact with heating the air, evaporating water, and interacting with clouds and greenhouse gasses in the atmosphere.

Moreover, some have argued that a strong aerosol radiative forcing means that the climate sensitivity has to be large in order to still be able to explain the temperature trend of the last 100 years, so they seem to be shooting in their own foot.

These optical depths can be used in conjunction with assumptions about aerosol radiative properties to calculate the direct forcing.

Regional effects of aerosol forcing are large; regional mean values of anthropogenic aerosol radiative forcing can be factors of 5 to 10 higher than the global mean values of 0.5 to 1.5 W m − 2 (IPCC, 2001).

It can also strengthen the Asian summer monsoon circulation and cause a local increase in precipitation, despite the global reduction of evaporation that compensates aerosol radiative heating at the surface (Miller et al., 2004b).

The current focus of the program is aerosol radiative forcing of climate: aerosol formation and evolution and aerosol properties that affect direct and indirect influences on climate and climate change.»

These differences are primarily due to aerosol radiative forcing, not climate sensitivity.

The global annual mean top of the atmosphere DMS aerosol all sky radiative forcing is − 2.03 W / m2, whereas, over the southern oceans during SH summer, the mean DMS aerosol radiative forcing reaches − 9.32 W / m2.»

But this information is not easily translated into aerosol radiative forcing, partly because we do not know what the pre-industrial concentrations were though direct observations, and because of the complexity of cloud - aerosol interactions (see Ch.

The complexity of radiative - dynamical response forced by volcanic impacts suggests that it is important to calculate aerosol radiative effects interactively within the model rather than prescribe them (Andronova et al., 1999; Broccoli et al., 2003).

Despite differences in volcanic aerosol parameters employed, models computing the aerosol radiative effects interactively yield tropical and global mean lower - stratospheric warmings that are fairly consistent with each other and with observations (Ramachandran et al., 2000; Hansen et al., 2002; Yang and Schlesinger, 2002; Stenchikov et al., 2004; Ramaswamy et al., 2006b); however, there is a considerable range in the responses in the polar stratosphere and troposphere.

I may have to re-read the Wild paper and again look exactly for what I failed to find the first time: local temperature observations on the surface matching the expected effects of the aerosol radiative forcings the paper does talk a lot about.

Global sulfate production plays a key role in aerosol radiative forcing; more than half of this production occurs in clouds.

Using the OPAC and SBDART models, optical properties and aerosol radiative forcing (ARF) in the spectral range 0.2 to 4 μm for composite aerosol and without - BC aerosol at the top of the atmosphere, surface and atmosphere were computed.

The effect of anthropogenic black carbon (BC) aerosol on snow is of enduring interest due to its role in aerosol radiative forcing and further consequences for Arctic and global climate change.

JCH — We can calculate the aerosol radiative forcing accurately enough, provided we know the aerosol amount and composition.

Since aerosols, clouds, and the ground surface have very different polarization spectral signatures, it is possible to sort out the aerosol radiative properties from changes in surface albedo and cloud contamination.

Satellite observations do play, however, a key role for evaluating models of the indirect aerosol radiative effect (Ghan et al., 2001b).

Miskolczi appears to have lost his FORTRAN coding skills — there are no new improvements being made to HARTCODE (it still can't calculate cloud or aerosol radiative effects, nor atmospheric LW cooling rates).

They, too, assume an equivalence in radiative forcing between GHG and aerosol, What they do is add different estimates of the aerosol radiative forcing to the GHG forcing, while keeping the temperature response fixed at the observed recent warming.

Moreover, some have argued that a strong aerosol radiative forcing means that the climate sensitivity has to be -LSB-...]

Can any of the experts lurking here refer me to any updates to the anthropogenic direct effect aerosol radiative forcing digram — Figure 6.8 -(Figure 401) in the TAR?

The global mean aerosol radiative forcing caused by the ship emissions ranges from -12.5 to -23 mW / m ^ 2, depending on whether the mixing between black carbon and sulfate is included in the model.

As long as the temporal pattern of variation in aerosol forcing is approximately correct, the need to achieve a reasonable fit to the temporal variation in global mean temperature and the difference between Northern and Southern Hemisphere temperatures can provide a useful constraint on the net aerosol radiative forcing (as demonstrated, e.g., by Harvey and Kaufmann, 2002; Stott et al., 2006c).

Geoengineering activities are mimicked in the models by modifying the volcanic aerosol radiative inputs, applied as variations in stratospheric optical depth over four zonal bands bounded by the equator, 30degreesN and 30degreesS.

They, too, assume an equivalence in radiative forcing between GHG and aerosol, What they do is add different estimates of the aerosol radiative forcing to the GHG forcing, while keeping the temperature response fixed at the observed recent warming.

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.

Not exact matches

The researchers [3] quantified China's current contribution to global «radiative forcing» (the imbalance, of human origin, of our planet's radiation budget), by differentiating between the contributions of long - life greenhouse gases, the ozone and its precursors, as well as aerosols.

Climate model projections neglecting these changes would continue to overestimate the radiative forcing and global warming in coming decades if these aerosols remain present at current values or increase.

Near - global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about — 0.1 W / m2, reducing the recent global warming that would otherwise have occurred.

Spanish and Portuguese researchers have analysed the composition and radiative effect of desert aerosols during two episodes which simultaneously affected Badajoz (Spain) and Évora (Portugal) in August 2012.

During this event, the aerosols stayed close to the surface due to the presence of a anticyclone hovering over the study region at sea - level, «reducing the amount of shortwave irradiance reaching the surface and causing greater radiative cooling,» states Obregón, who likens the effects of desert dust with those resulting from certain forest fires or episodes of high pollution.

For this reason, a group of researchers from Extremadura (Spain) and Portugal has analysed the radiative effect of a type of natural aerosol (the dust from the desert areas), of great interest to the Iberian Peninsula due to the proximity of the Sahara desert.

Radiative forcing, especially that due to aerosols, is highly uncertain for the period 1750 - 1850 as there is little modeling and even less data to constrain those models.

While a relatively minor part of the overall aerosol mass, changes in the anthropogenic portion of aerosols since 1750 have resulted in a globally averaged net radiative forcing of roughly -1.2 W / m2, in comparison to the overall average CO2 forcing of +1.66 W / m2.

Sally, who was nominated by Dr. Beat Schmid, Associate Director, Atmospheric Sciences and Global Change Division, was honored for her exceptional contribution in the field of atmospheric science, particularly in her efforts to improve understanding of the radiative effect of clouds and aerosols on the Earth's atmosphere and their representation in climate models.

Continuous measurements was used for the first time to estimate the direct radiative feedback of natural aerosols

Forcing caused by changes in the Sun's brightness, by dust in the atmosphere, or by volcanic aerosols can also be translated into radiative forcing.

[Response: There's some good thinking here, but I think you may have confused Gavin's discussion of the attempts by Andrae et al to infer climate sensitivity from recent warming with the question of whether there's a different sensitivity coefficient for aerosol vs GHG radiative forcing.

Steven J. Ghan • Contributing Author, Working Group I, «Aerosols, Their Direct and Indirect Effects,» IPCC Third Assessment Report (2001) • Contributing Author, Working Group I, «Radiative Forcing of Climate Change,» IPCC Third Assessment Report (2001).

The field study was dubbed CARES, short for Carbonaceous Aerosol and Radiative Effects Study.

Jerome Fast has lead a team of PNNL scientists that have contributed a gas - phase chemistry mechanism, an sectional aerosol model, cloud chemistry, cloud - aerosol interactions, and radiative feedback processes into the chemistry version of Weather Research and Forecasting (WRF - chem) model.

In addition, researchers calculated the changes in the shortwave and longwave and net radiation between the pre-industrial simulation and the present - day simulations to estimate the radiative forcing resulting from the aerosol effects on cirrus clouds.

That's far from the worst flaw in his calculation, since his two biggest blunders are the neglect of the radiative cooling due to sulfate aerosols (known to be a critical factor in the period in question) and his neglect of the many links in the chain of physical effects needed to translate a top of atmosphere radiative imbalance to a change in net surface energy flux imbalance.

Areas of expertise: Satellite remote sensing, atmospheric aerosols, climatology, radiative forcing

Takemura, T., et al., 2002: Single scattering albedo and radiative forcing of various aerosol species with a global three - dimensional model.

Stratospheric heating by potential geoengineering aerosols Geoengineering aerosols change stratospheric radiative heating rates Heating rates depend on aerosol species and size

For example, we know the past CO2 radiative forcing to very high accuracy, but there are more uncertainties in the aerosol forcing; applying a consistent climate sensitivity to both CO2 and aerosols, you can get a match to the observed record for a range of different supposed aerosol forcings, but you can't take it too far.