Sentences with phrase «of aerosol increases»

The authors examine various potential causes of aerosol increases and identify a number of small volcanoes over the last decade as the most plausible source.

If the direct effect of the aerosol increase is considered, surface temperatures will not get as warm because the aerosols reflect solar radiation.

The SKY experiment provided proof of concept in that they found the formation rate of aerosol increased in the presence of ions generated using a 580 MeV electron beam (Enghoff et al. 2011).

Not exact matches

The movement away from a traditional aerosol can not only improves the user experience by increasing efficiency and lowering weight but also demonstrates responsible packaging by replacing a potentially hazardous can with a pouch that can be disposed of in the regular waste stream.

China «could cause some decreases [in stratospheric aerosols] if that is the source,» Neely says, adding that growing SO2 emissions from India could also increase cooling if humans are the dominant cause of injecting aerosols into the atmosphere.

On the other hand, «if some volcanoes that are large enough go off and if they are the dominant cause [of increasing aerosols], then we will probably see some increases» in cooling.

Determining whether humans or volcanoes explain more of the increase in stratospheric aerosols is the focus of ongoing research, says PhD candidate Ryan Neely of the University of Colorado, who contributed to the NOAA research.

One aerosol, black carbon, is of increasing concern for Arctic nations worried about the pace of climate change in the far north, which is warming twice as fast as the global average.

While it is still possible that other factors, such as heat storage in other oceans or an increase in aerosols, have led to cooling at the Earth's surface, this research is yet another piece of evidence that strongly points to the Pacific Ocean as the reason behind a slowdown in warming.

These results imply that the chlorine activation efficiency of the aerosol particles increases rapidly as the temperature approaches the ice frost point regardless of the phase or composition of the particles.

The aerosols catalyze the formation of ice in the clouds, which could increase precipitation, although more research needs to be done on that linkage, Creamean said.

The scientists expect further warming in the Arctic as levels of greenhouse gases will continue to increase and aerosol particle emissions will likely decrease to combat air pollution in different parts of the world.

Black carbon aerosols — particles of carbon that rise into the atmosphere when biomass, agricultural waste, and fossil fuels are burned in an incomplete way — are important for understanding climate change, as they absorb sunlight, leading to higher atmospheric temperatures, and can also coat Arctic snow with a darker layer, reducing its reflectivity and leading to increased melting.

This was due to a combination of factors: a less active sun, higher levels of cooling aerosols from volcanoes and Asian factories, and increased heat uptake by the oceans.

A few of the main points of the third assessment report issued in 2001 include: An increasing body of observations gives a collective picture of a warming world and other changes in the climate system; emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate; confidence in the ability of models to project future climate has increased; and there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.

Simulating natural and humanmade climate drivers, scientists showed that the decline in rainfall is primarily a response to humanmade increases in greenhouse gases as well as a thinning of the ozone caused by humanmade aerosol emissions.

«The trends in Africa of hot summers getting hotter and rainy seasons drying out are linked with factors that include increasing greenhouse gases and aerosols in the atmosphere,» said Ming Cai, a program director in the National Science Foundation's Division of Atmospheric and Geospace Sciences, which funded the research.

When the wind slows down, the concentration of small particles of air pollution (aerosols) increase, which help increase haze and leads to solar dimming in the area.

Indeed, conventional wisdom held that higher levels of aerosol pollution in the atmosphere should cool the earth's climate because aerosols can increase cloudiness; they not only reduce precipitation, which raises the water content in clouds, but they also increase the size of the individual water droplets, which in turn causes more warming sunlight to be reflected back into space.

The study, published Wednesday in the journal Nature, showed that the production of tar sands and other heavy oil — thick, highly viscous crude oil that is difficult to produce — are a major source of aerosols, a component of fine particle air pollution, which can affect regional weather patterns and increase the risk of lung and heart disease.

A 2013 computer simulation of this process found increased aerosols alone did result in more lightning due to ice crystal collisions, although at very large aerosol volumes the effect was muted.

A key question facing researchers is whether increased electrification is the result of more aerosols or an abundance of warm air.

Scientists have already linked aerosol emissions to increases in lightning over areas of the Amazon prone to forest fires (pdf) as well as regions of China with thick air pollution.

And while researchers are still striving to fully understand the health and environmental impact of increased levels of secondary organic aerosols in the atmosphere, studies have linked exposure to outdoor aerosols generally to morbidity and mortality outcomes.

Aerosols that are close in size or larger than the wavelengths of visible light tend to scatter all colors indiscriminately, increasing the overall brightness of the sky but dampening color contrast.

Formation of solid and liquid aerosol particles is increased.

But even this paper qualifies its predictions (whether or not aerosols would so increase was unknown) and speculates that nuclear power may have largely replaced fossil fuels as a means of energy production (thereby, presumably, removing the aerosol problem).

In addition, our deficient understanding of aerosol forcing also hinders our ability to use the modern temperature record to constrain the «climate sensitivity» — the operative parameter in determining exactly how much warming will result from a given increase in CO2 concentration.

Of the other strand, aerosol cooling, Rasool and Schneider, Science, July 1971, p 138, «Atmospheric Carbon Dioxide and Aerosols: Effects of Large Increases on Global Climate» is the best exemplaOf the other strand, aerosol cooling, Rasool and Schneider, Science, July 1971, p 138, «Atmospheric Carbon Dioxide and Aerosols: Effects of Large Increases on Global Climate» is the best exemplaof Large Increases on Global Climate» is the best exemplar.

The Canadian model suppresses the influence of aerosols in the regional distribution far more, as the direct forcing of GHGs increases to 3.3 and 5.8 W / m2 for resp.

Here a reaction on the main points about the natural (solar, volcanic) vs. man - made (GHGs, aerosols) sensitivity: — If there was a larger temperature variation in the past millennium, the mathematical evidence is that an increase of one of the terms of the temperature trend equation must go at the cost of one or more other terms of the equation.

Given the increasing availability of aerosol composition data collected from aircraft, the team expects that their approach can be successfully applied to improve understanding of a wide range of sophisticated processes and phenomena related to aerosols, including how properties evolve with time and the dynamic interactions between aerosols and clouds.

The Hadcm3 model has calculated the largest increase in temperature which may be attributed to the reduction of aerosol load (40 %) over the period 1990 - 1999 somewhere in NE Europe, other models do that more in Southern Europe.

Compared to the past decades, the pattern (more emissions in South Asia) and the relative forcings are completely different, with much less relative influence of aerosols than today (due to faster increasing CO2 levels).

-- It is practically proven that tropospheric aerosols have (far) less influence on temperature than expected by current models, see my comment on aerosols here and the lack of increase in insolation, despite a huge reduction of aerosols in Europe, according to Philipona ea.

And finally, current theories based on greenhouse gas increases, changes in solar, volcanic, ozone, land use and aerosol forcing do a pretty good job of explaining the temperature changes over the 20th Century.

The Intergovernmental Panel on Climate Change (IPCC) considers that the increase in aerosols and clouds since pre-industrial times represents one of the largest sources of uncertainty in climate change5.

The CARES field campaign was designed to increase scientific knowledge about the evolution of black carbon, primary organic aerosols (POA), and secondary organic aerosols (SOA) from both human - caused and natural (biogenic) sources.

Analyses of the ground and aircraft data performed by Setyan et al. (2012), Shilling et al. (2013), and Kleinman et al. (2016) showed that organic aerosol production increased when human - caused emissions from Sacramento mixed with air rich in isoprene, an organic compound wafting from many plants that originate in the area's foothills.

Possible reasons include increased oceanic circulation leading to increased subduction of heat into the ocean, higher than normal levels of stratospheric aerosols due to volcanoes during the past decade, incorrect ozone levels used as input to the models, lower than expected solar output during the last few years, or poorly modeled cloud feedback effects.

The potential risks around sulfate aerosol solar geoengineering include alteration of regional precipitation patterns, its effects on human health, and the potential damage to Earth's ozone layer by increased stratospheric sulfate particles.

When Aldrin adds a fixed cloud lifetime effect of -0.25 W / m ^ 2 forcing on top of his variable parameter direct and (1st) indirect aerosol forcing, the mode of the sensitivity PDF increases from 1.6 to 1.8.

Ice sheet albedo forcing is estimated to have caused a global mean forcing of about — 3.2 W m — 2 (based on a range of several LGM simulations) and radiative forcing from increased atmospheric aerosols (primarily dust and vegetation) is estimated to have been about — 1 W m — 2 each.

Reduction of the amount of atmospheric CH4 and related gases is needed to counterbalance expected forcing from increasing N2O and decreasing sulfate aerosols.

Expectations of decreases in large source regions such as China [195] may be counteracted by aerosol increases other places as global population continues to increase.

SAM involves injecting sulfur aerosols into the stratosphere to increase the reflectivity of Earth's atmosphere.

In general, the risk of aerosol transmission increases with proximity and duration of exposure to the source; however, once aerosolized, certain pathogens may remain infective over long distances, depending on particle size, the nature of the pathogen, and such environmental factors as temperature and humidity.3

In one study, administration of an aerosol containing nedocromil sodium of approximately 15 mg increased the lag time for the dogs to cough after exposure to a citric acid aerosol (31).

The AGU statement says that the «not natural» climate changes being recorded — perhaps best exemplified (albeit, I'll admit, overly simple) by the cascade of recent years all warmer than anything else since 1850 — are «best explained» by the increasing accumulation of man - made greenhouse gases and aerosols.

For example, they predicted the expansion of the Hadley cells, the poleward movement of storm tracks, the rising of the tropopause, the rising of the effective radiating altitude, the circulation of aerosols in the atmosphere, the modelling of the transmission of radiation through the atmosphere, the clear sky super greenhouse effect that results from increased water vapor in the tropics, the near constancy of relative humidity, and polar amplification, the cooling of the stratosphere while the troposphere warmed.