Sentences with phrase «by aerosol particles»

This work eventually led to investigation of how planetary cooling might be caused by the aerosol particles arising from large - scale fires generated by a nuclear war.

Their freezing can either be triggered by aerosol particles acting as a so - called ice nuclei (IN), or occur homogeneously (without IN) at about − 38 ◦ C The goal of many laboratory studies was and is to assess the ice nucleation ability of selected aerosol particles of a... http://search.proquest.com/openview/421dd0783b387a8e030902328dcc6f23/1.pdf?pq-origsite=gscholar&cbl=105744

The photoacoustic soot spectrometer (PASS) measures light absorption by aerosol particles.

The quality of air is determined to a considerable extent by aerosol particles.

It is caused by aerosol particles, but scientists don't know all the details of the complex chemistry involved.

Not exact matches

This year, Summit's list of long - term visitors includes Brandon Strellis, an environmental engineering graduate student from the Georgia Institute of Technology studying how aerosols influence how much energy is reflected and absorbed by Greenland's ice — and where those particles are coming from.

After allowing for humidity and rainfall, they found that «aerosol optical thickness» — a measure of the concentration of atmospheric particles — decreased by only 10 to 15 per cent compared with the same periods in 2002 to 2007 (Geophysical Research Letters, in press).

Dust devils might affect Mars's atmosphere by whipping particles to high altitudes, where the fine aerosols help control the planet's dry climate.

Aerosols can also have a cooling effect, if they are bright, like the sulfate particles emitted by volcanoes.

The team started by looking at the formation of the very small particles — a process called aerosol nucleation — by mimicking atmospheric conditions inside an ultraclean steel «cloud chamber», which Kirkby says is the cleanest ever created.

And by carefully measuring and modeling the resulting changes in atmospheric composition, scientists could improve their estimate of how sensitive Earth's climate is to CO2, said lead author Joyce Penner, a professor of atmospheric science at the University of Michigan whose work focuses on improving global climate models and their ability to model the interplay between clouds and aerosol particles.

A new simulation created by scientists at NASA's Goddard Space Flight Center in Greenbelt, Md., reveals just how far around the globe such aerosol particles can fly on the wind.

The difference in lightning activity can't be explained by changes in the weather, according to the study's authors, who conclude that aerosol particles emitted in ship exhaust are changing how storm clouds form over the ocean.

On their own, aerosol particles are tiny; when a cloud droplet becomes a rain droplet, it grows by a factor of a million as droplets crash and coalesce together.

Indeed, the reduction in the emission of precursors to polluting particles (sulphur dioxide) would diminish the concealing effects of Chinese aerosols, and would speed up warming, unless this effect were to be compensated elsewhere, for instance by significantly reducing long - life greenhouse gas emissions and «black carbon.»

«When biogenic VOCs are oxidized, they give rise to aerosol particles that cool the climate by reflecting part of the Sun's radiation back into space,» Artaxo said.

Soot particles, also known as black carbon aerosols, affect climate by absorbing sunlight, which warms the surrounding air and limits the amount of solar radiation that reaches the ground.

These particles pose health risks to populations, especially to the medically vulnerable, By infusing CATS data directly into aerosol models, data from CATS can make a difference in tracking and responding to impacts of similar events in the future.

Albedo modification would work by lacing the atmosphere with tiny particles or aerosols that would reflect sunlight and mimic natural processes.

Funded by the U.K. government, SPICE was set up in 2010 by British research institutions to investigate whether aerosols, such as sulfate particles, could be injected into Earth's stratosphere to scatter sunlight back into space, thereby stalling global warming.

Evidence suggests that Ebola virus is most often transmitted by direct contact, but there is concern that transmission could occur through inhaled aerosol particles — which may be generated by many different medical procedures.

Ginot and his team of researchers can also track aerosols — small particles in the atmosphere that fall with snow and get trapped and stored in the ice, layer by layer, as the years pass.

Like the particles emitted during volcanic eruptions, sulfate aerosols cool the Earth by blocking a portion of the sun's rays.

Two important aerosol species, sulfate and organic particles, have large natural biogenic sources that depend in a highly complex fashion on environmental and ecological parameters and therefore are prone to influence by global change.

That's the conclusion of a team of scientists using a new approach to study tiny atmospheric particles called aerosols that can influence climate by absorbing or reflecting sunlight and seeding clouds.

By engineering breaking waves of natural ocean water under purified air in the lab, they were able to isolate and analyze aerosols from the spray and determine how life within the water altered the chemistry of the particles.

Now an international team of researchers led by the lung researcher Marianne Geiser from the Institute of Anatomy at the University of Bern and the aerosol researcher Josef Dommen from the Paul Scherrer Institute PSI has shown that secondary particles from gasoline combustion in Euro 5 engines directly damage lung tissue as well as weaken its defense functions.

The recently published research results provide further evidence that forests can affect the climate by producing low - volatility vapours that are able to condense and grow aerosol particles.

Small particles called aerosols that are released into the air by smoke may also reduce the likelihood of rainfall.

* Red areas show aerosol plumes dominated by small particles.

But sulphate aerosols are not the major aerosol component by particle mass or number.

Therefore, considering the large contribution of these particles to the aerosol mass concentration in the atmosphere and the importance of the INPs, we study the ability of these particles as INPs by immersion freezing mode.

A team of scientists led by Pacific Northwest National Laboratory atmospheric researcher Dr. Susannah Burrows and collaborator Daniel McCoy, who studies clouds and climate at the University of Washington, reveal how tiny natural particles given off by marine organisms — airborne droplets and solid particles called aerosols — nearly double cloud droplet numbers in the summer, which boosts the amount of sunlight reflected back to space.

Why It Matters: Aerosols, tiny airborne particles of dust and pollution suspended in the atmosphere, affect the atmosphere and the surface of Earth by scattering and absorbing light.

Because much of Earth's land mass is covered by plants, there is a large source of these biogenic aerosol particles that need to be accounted for in climate change prediction.

A large portion of secondary organic aerosols - tiny particles in the air we breathe that contribute to cloud formation and precipitation - arise from a combination of man - made pollution and molecules given off by plant matter.

CLOUD shows that organic vapours emitted by trees produce abundant aerosol particles in the atmosphere in the absence of sulphuric acid.

The instrument vaporizes aerosol particles either by laser ablation or flash vaporization, this way converting the particulate matter into gaseous material.

Results: Ubiquitous carbon - rich aerosol particles created by emissions from cars, trees, and other sources alter our climate and affect air quality.

Secondary organic aerosols, or SOAs, are created when hydrocarbon gases, given off by everything from pine trees to snow blowers, undergo a series of chemical reactions in the atmosphere to produce particles.

Reference: Jiwen Fan, Daniel Rosenfeld, Yuwei Zhang, Scott E. Giangrande, Zhanqing Li, Luiz A.T. Machado, Scot T. Martin, Yan Yang, Jian Wang, Paulo Artaxo, Henrique M.J. Barbosa, Ramon C. Braga, Jennifer M. Comstock, Zhe Feng, Wenhua Gao, Helber B. Gomes, Fan Mei, Christopher Pöhlker, Mira L. Pöhlker, Ulrich Pöschl, and Rodrigo A.F. de Souza, Substantial convection and precipitation enhancements by ultrafine aerosol particles, Science, Jan. 26, 2018, DOI: 10.1126 / science.aan8461.

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.

The planet's albedo, around 30 percent, is governed by cloud cover and the quantity of atmospheric particles called aerosols.

In this case, large amounts of sulphate aerosols (small particles) are injected into the stratosphere by large explosive eruptions (the most recent one being Mt. Pinatubo in 1991).

According to «Atmospheric particles and nuclei» by Götz et al. (1991), Junge (1963) proposed on the basis of aerosol measurements that «large» and «giant» particles (radius greater than 0.1 micro-meter) constitute the majority of CCN, independently of their chemical composition.

«A rapid cutback in greenhouse gas emissions could speed up global warming... because current global warming is offset by global dimming — the 2 - 3ºC of cooling cause by industrial pollution, known to scientists as aerosol particles, in the atmosphere.»

My question is: does the retroreflectivity of the larger droplets, i.e. back towards the light source, play into the sulfur aerosol issue or is it simply averaged out by the bulk effect of all the aerosol particles present in the apparently white haze?

The composition of sea spray aerosol particles are influenced by both chlorophyll - a concentrations and microbial degradation.

The spotlight is on the effect of aerosol - particles released by industrial activity - on the Earth's climate.

The Single Particle Soot Photometer (SP2) measures the soot (black carbon) mass of individual aerosol particles by laser - induced incandescence down to concentrations as low as ng / m ^ 3.