Sentences with phrase «effects of aerosols»

That cooling is a response to the decrease in penetrating solar radiation caused by the «shading» effects of aerosols spewed into the stratosphere by the explosive volcano — not from a decrease in manmade greenhouse gases.

The direct and indirect radiative effects of aerosols suspended in the atmosphere above clouds (ACA) are a highly uncertain component of both regional and global climate.

After the adjustments noted above for latent heat and better accounting for the effects of aerosols and water vapor in the ASR, the revised estimates are 333 and 63 W m − 2 for the downward and net surface LW.

Here, in part I, I'll review some of the basic processes that are important in determining the climate effects of aerosols, focusing in particular on their formation.

«Scientists have talked about Arctic melting and albedo decrease for nearly 50 years,» said Ramanathan, a distinguished professor of climate and atmospheric sciences who has previously conducted similar research on the global dimming effects of aerosols.

The largest uncertainty in that comparison comes from the estimated effects of aerosols in the atmosphere, which can variously shade Earth or warm it.

This section assesses (1) the impact of meteorological (climatic) factors like wind, temperature and precipitation on the natural aerosol burden and (2) possible effects of aerosols on climate parameters and biogeochemistry.

Reflective effects of aerosols recently directly observed have reflected much radiation back to space, reducing warming effects, not just slowing them down.

ACC would also include any «special» regional effects of aerosols; aside from that, though, I think either term works.

He adds that Lindzen has also not accounted for the possible cooling effects of aerosols, which, if ignored, also lead to an underestimate of climate sensitivity.

This is because the net warming it reports includes the cooling effects of aerosols which partly masks the warming caused by greenhouse gases.

Lindzen has also not accounted for the possible cooling effects of aerosols, which, if ignored, also lead to an underestimate of climate sensitivity

More research on the effects of aerosols is still needed, Unger cautions.

These agents include tropospheric and stratospheric ozone, all of the non-sulphate aerosols, the indirect effects of aerosols on cloud albedo and lifetime, the effects of land use and solar variability.

Other types of forcing that vary across the ensemble include solar variability, the indirect effects of aerosols on clouds and the effects of land use change on land surface albedo and other land surface properties (Table 10.1).

effects of aerosols on cloud properties (including cloud fraction, cloud microphysical parameters, and precipitation efficiency), which may modify the hydrological cycle without significant radiative impacts;

IPCC2013 SPM - 10 admitted there may be «in some models, an overestimate of the response to increasing greenhouse gas and other anthropogenic forcing (dominated by the effects of aerosols)», but retained the alarming upper limit of 4.5 º C from IPCC2007.

Considering the surface radiative forcing may enable quantification of the effects of aerosols on the surface

Atmospheric carbon dioxide equivalent levels were around 455 ppm CO2 - e in 2005 if you ignore the cooling effects of aerosols but around 375 ppm CO2 - e in 2005 if you include the cooling effects of aerosols and landuse changes: see the IPCC (2007) Working Group III report at page 102, available at http://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-chapter1.pdf.

Aerosols Many of the proposed feedbacks involve the cooling effects of aerosols.

The direct radiative effects of aerosols can be divided in reflection and absorption.

This is before accounting for the cooling effects of aerosols.

Subject to limitations of the standard TOA forcing except for ability to calculate indirect and semidirect effects of aerosols

This is AF, not RF, since the observed NH and SH temperatures on which it is based reflect all effects of aerosols - they can not and do not distinguish the main RF component from the total AF.

The effects of aerosols and landuse changes reduce radiative forcing so that the net forcing of human activities is in the range of 311 to 435 ppm CO2 - eq, with a central estimate of about 375 ppm CO2 - eq.»

In this paper we present results from various field experiments demonstrating the contribution that the multi-angle multi-spectral photopolarimetric remote sensing measurements of the NASA Glory mission will make to the determination of the direct and indirect radiative effects of aerosols.

The effects of aerosols on the climate are a problem for the L&S model, as the authors almost admit in the paper:

It should be noted that the inertia of the climate system and the counteracting effects of aerosols delay the appearance of a climate change, makes the issue more difficult to grasp, but does not diminish the possible seriousness of the issues.

Fan went to China in 2008 for an ARM Mobile Facility field campaign studying the climatic effects of aerosols in that country's fast - changing atmosphere.

However, given the sensitivity of the Arctic to external forcing and the intense interest in the effects of aerosols on its climate, it is important to examine and quantify the effects of individual groups of anthropogenic forcing agents.

Ramanathan and Carmichael (2008), on the other hand, examined both the warming and cooling effects of aerosols.

Figure 9.5 shows that simulations that incorporate anthropogenic forcings, including increasing greenhouse gas concentrations and the effects of aerosols, and that also incorporate natural external forcings provide a consistent explanation of the observed temperature record, whereas simulations that include only natural forcings do not simulate the warming observed over the last three decades.

This was our lab's first attempt to incorporate the indirect effects of aerosols in a climate model.

The authors of the Science journal report provide new calculations on the cancelling effects of aerosols and GHGs on tropical cyclones.

In addition to the Ramanathan paper cited above by Chief Hydrologist, the review article by Ramanathan and Carmichael is informative in quantifying both the positive and negative forcing effects of aerosols as a function of their components.

Then, after giving a talk to the Bush - Cheney White House, he agonized about whether he should have ignored the cooling effects of aerosols because it gave Cheney an «out,» enabling him and others to make the specious argument that aerosols somehow balance out the trillions of tons of CO2 emitted every year.

Even worse, the models inadequately include the diverse myraid effects of aerosols and land use / land cover change on the climate system, so they are already hindered in their ability to accurately represent the real world spectrum of human climate forcings.

The indirect effects of aerosols have more uncertainty.

The overwhelming uncertainty in determining TCR from historical data is the uncertainty about the historical net warming or cooling effects of aerosols as discussed in Lewis and Curry (2014).

If analysis of historical data on GHG rise and net effects of aerosols establishes beta = 0.5, then TCR = 1.2 C. But, beta is uncertain and might be as low as 0.4, in which case TCR = 1.3 C. But, TCR (1 + beta) = 1.8 C and only has uncertainty introduced by uncertainty in the historical GMST and CO2 level rise.

As his survey question is presented, where would one include the diverse effects of aerosols and of land use / land cover change?

Here is a quick summary of the issue: The effects of aerosols on clouds consist of three linked elements.

Some models include volcanic effects by simply perturbing the incoming shortwave radiation at the top of the atmosphere, while others simulate explicitly the radiative effects of the aerosols in the stratosphere.

To evaluate the global effects of aerosols on the direct radiative balance, tropospheric chemistry, and cloud properties of the earth's atmosphere requires high - precision remote sensing that is sensitive to the aerosol optical thickness, size istribution, refractive index, and number density.

In models that include indirect effects, different treatments of the indirect effect are used, including changing the albedo of clouds according to an off - line calculation (e.g., Tett et al., 2002) and a fully interactive treatment of the effects of aerosols on clouds (e.g., Stott et al., 2006b).

In the very long term, a warming limit of 1.5 C requires total greenhouse - gas concentrations — plus the effects of aerosols — to be below a level of 400ppm CO2eq.

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.

The leveling off between the 1940s and 1970s may be explained by natural variability and possibly by cooling effects of aerosols generated by the rapid economic growth after World War II.

The problem arises, I believe, when strong feedbacks, «masking» effects of aerosols and volcanoes and other uncertain assumptions are fed into computer models to generate catastrophic scenarios for the near - medium future.

Research into the effects of aerosols with various compositions has been underway for over a decade now.