Sentences with phrase «of aerosols in the stratosphere»

Then there are the tests of climate changes themselves: how does a model respond to the addition of aerosols in the stratosphere such as was seen in the Mt Pinatubo «natural experiment»?

In my mind, the most serious peril of sulfate geoengineering is one that stems from a problem that is not at all in dispute: the fact that the lifetime of CO2 in the atmosphere is centuries to millennia, whereas the lifetime of aerosols in the stratosphere is at best a few years.

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.

Not exact matches

The effect also illustrates one proposal for so - called geoengineering — the deliberate, large - scale manipulation of the planetary environment — that would use various means to create such sulfuric acid aerosols in the stratosphere to reflect sunlight and thereby hopefully forestall catastrophic climate change.

Such sulfuric acid aerosols are already responsible for the bulk of nacreous clouds that form in the polar stratosphere; added particles would just amp up the natural process (although it might also amp up damage the ozone layer).

It's designed to track an aerosol plume in the stratosphere at a height of 70,000 feet.

In fact, the aerosol layer in the stratosphere, which is also composed of sulphur particles, seems to have become thicker in recent yearIn fact, the aerosol layer in the stratosphere, which is also composed of sulphur particles, seems to have become thicker in recent yearin the stratosphere, which is also composed of sulphur particles, seems to have become thicker in recent yearin recent years.

Some of those gases in the chimney system such as chlorofluorocarbons (found in refrigerants and aerosols) and bromine compounds (found in products such as fire extinguishers) are man - made and can become trapped in the stratosphere, lingering there for years.

They fear that similar aerosol already in the northern stratosphere, which came from the eruption of Mount Pinatubo in the Philippines in June 1991, may cause a dramatic loss of ozone in the northern hemisphere next February or March.

Alcide di Sarra of La Sapienza University in Rome and colleagues from an Italian - Danish team found that the volcanic aerosol from Mount Pinatubo penetrated the Arctic stratosphere in relatively thin layers, at altitudes below 16 kilometres.

OMPS is a three - part instrument: a nadir mapper that maps ozone, SO2 and aerosols; a nadir profiler that measures the vertical distribution of ozone in the stratosphere; and a limb profiler that measures aerosols in the upper troposphere, stratosphere and mesosphere with high vertical resolution.

«And at the end of the summer, the «lid» comes back down, which leaves aerosols in the stratosphere,» he explains.

The main removal process for aerosols is related to rain and clouds, and up in the stratosphere there isn't any to speak of.

Sulphur dioxide reacts with water vapour to form long - lived droplets (aerosols) of sulphuric acid, and about 10 million tons of these droplets are known to have accumulated in the stratosphere as a result of the eruption.

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 1991In 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 1991in 1991).

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.

Thus the changes in the stratosphere are basically a function of the greenhouse gases, ozone levels and volcanic aerosols there.

Rough calculations show if you drill about a dozen mine shafts as deep as possible into the thing, and plunk megaton nuclear bombs down there, and then fire them off simultaneously, you'll get a repeat of the Long Valley Caldera explosion of about 800,000 years ago — which coated everything east of it with miles of ash and injected a giant aerosol cloud into the stratosphere — the ash layer alone formed a triangle stretching from the caldera to Louisiana to North Dakota, including all of Arizona and most of Idaho and everything in between — I bet that would have a cooling factor of at least -30 W / m ^ 2 — and you could go and do the Yellowstone Plateau at the same time — geoengineering at its finest.

«Geoengineering» by reducing insolation with aerosols in the stratosphere will also reduce the effectiveness of solar panels.

Since aerosols last much longer in the stratosphere than they do in the rainy troposphere, the amount of aerosol - forming substance that would need to be injected into the stratosphere annually is far less than what would be needed to give a similar cooling effect in the troposphere, though so far as the stratospheric aerosol burden goes, it would still be a bit like making the Earth a permanently volcanic planet (think of a Pinatubo or two a year, forever).

If we would pump aerosols in the stratosphere to artificially cool the Earth and thereby compensate (part of) the current climate warming, we would be permanently living under a slight sunshade.

After a large volcanic eruption, the layer of sulfate aerosols in the stratosphere gets thicker, and we see, in the historic record, that the Earth cools down in response.

Not it is not similar because one event injected sulfate aerosols into the stratosphere where they stayed for years and affected the globe while the other («human particulates and aerosol pollution») were produced in the troposphere and have a residency time in the atmosphere of about 4 days and had only a regional effect.

One driver of temperatures in this region is the abundance and variability of ozone, but water vapor, volcanic aerosols, and dynamical changes such as the Quasi - Biennial Oscillation (QBO) are also significant; anthropogenic increases in other greenhouse gases such as carbon dioxide play a lesser but significant role in the lower stratosphere.

In fact, the major effect of significant volcanic eruptions is cooling due to the sulfate aerosols that they release (although in order to have a significant cooling effect, the eruption has to be large enough that it injects the aerosols into the stratosphere where they can stay around longer... and it apparently helps if the eruption is reasonably near to the equatorIn fact, the major effect of significant volcanic eruptions is cooling due to the sulfate aerosols that they release (although in order to have a significant cooling effect, the eruption has to be large enough that it injects the aerosols into the stratosphere where they can stay around longer... and it apparently helps if the eruption is reasonably near to the equatorin order to have a significant cooling effect, the eruption has to be large enough that it injects the aerosols into the stratosphere where they can stay around longer... and it apparently helps if the eruption is reasonably near to the equator).

Here I summarize two recent papers that model solar radiation management: the practice of offsetting global warming by partially blocking sunlight, whether by seeding clouds, adding sulfate aerosols to the stratosphere, or placing giant mirrors in space.

«Since 1997, when Pinatubo's aerosol settled out, the stratosphere has been exceptionally clear... Half or more of the warming since 1995 may due to the lack of large volcanic eruptions... That's about 0.13 °C... The remaining climate change is presumably caused by other forces, such as solar variability, El Nino, Atlantic AMO warming in 1995, lower Albedo and maybe even a little greenhouse gas.»

I consider it as very likely that the 20 year trends will still be statistically significant also in three, five or ten years from now, unless there is some strong volcanic explosion that blows a lot of reflecting aerosols in the stratosphere causing a temporary temperature dip, or some other cause the effect of which is explainable within the framework of current knowledge about the climate system, but as event not really predictable.

Stratospheric aerosols affect the chemistry and transport processes in the stratosphere, resulting in the depletion of ozone (Brasseur and Granier, 1992; Tie et al., 1994; Solomon et al., 1996; Chipperfield et al., 2003).

However the models» simplified treatment of aerosol microphysics introduces biases; further, they usually overestimate the mixing at the tropopause level and intensity of meridional transport in the stratosphere (Douglass et al., 2003; Schoeberl et al., 2003).

Aerosols from volcanic eruptions do have a cooling effect once they reach the stratosphere but the effect of high wind speed in the upper atmosphere would rapidly disperse these, and any local effects would be very slight.

Until the 1990s, the widespread use of chlorofluorocarbons (CFCs) for refrigerants and aerosols created an ozone hole in the Earth's stratosphere (the second layer of the atmosphere from Earth's surface) over Antarctica.

Sulphate aerosols in the stratosphere (which were the main topic of this piece and these Climate Feedback posts) and mirrors / refractors in space (also in that piece, and in this paper by Roger Angel) both have the potential to provide as much by way of negative forcing as a doubling of CO2 provides by way of positive forcing.

Ridley and his colleagues also tracked the source of aerosols in the lower stratosphere from volcanic eruptions during the 2000s.

One knob that we could control: The amount of sulphate aerosols in the stratosphere.

Of course temperatures in the troposphere is influenced by volcanic aerosols in the troposphere and stratosphere.

Although we focus on a hypothesized CR - cloud connection, we note that it is difficult to separate changes in the CR flux from accompanying variations in solar irradiance and the solar wind, for which numerous causal links to climate have also been proposed, including: the influence of UV spectral irradiance on stratospheric heating and dynamic stratosphere - troposphere links (Haigh 1996); UV irradiance and radiative damage to phytoplankton influencing the release of volatile precursor compounds which form sulphate aerosols over ocean environments (Kniveton et al. 2003); an amplification of total solar irradiance (TSI) variations by the addition of energy in cloud - free regions enhancing tropospheric circulation features (Meehl et al. 2008; Roy & Haigh 2010); numerous solar - related influences (including solar wind inputs) to the properties of the global electric circuit (GEC) and associated microphysical cloud changes (Tinsley 2008).

Here, the authors use satellite and aircraft data to investigate the radiative impact of volcanic aerosols in the lowermost stratosphere since the year 2000.

There is no obvious answer, unless you look to stratospheric aerosol cooling — in the stratosphere, you'd need about 10 % of the sulphates you'd require in the troposphere for the same cooling effect.

As a test of the models» annular sensitivity, the response to volcanic aerosols in the stratosphere is calculated during the winter following five major tropical eruptions.

In other words: Proposed strategies to alter the amount of sunlight hitting the Earth's surface by (for example) deliberately injecting millions of tons of sulfate aerosols into the stratosphere pose enormous risks and uncertainties and don «t address the underlying causes of global warming or other major risks from rising concentrations of carbon dioxide, such as ocean acidification.

For instance, given the physics of sulphate aerosols in the stratosphere (short wave reflectors, long wave absorbers), it would be surprising if putting in the aerosols seen during the Pinatubo eruption did not reduce the planetary temperature while warming the stratosphere in the model.

Tinkering with the Earth and its atmosphere in an attempt to fend off global warming — a.k.a. geoengineering — seems like the stuff of science fiction: Lacing the stratosphere with sulfur aerosols or whitening clouds over the ocean to reflect sunlight back into space.

What does seem to be known is that aerosols fall out of the lower atmosphere (as high as they can be launched with conventional bombs) in days, and persist for less than 2 years when launched into the stratosphere by a major volcanic event like Pinatubo which was equivalent to several H bombs.

Until late in the last century, widespread usage of household and commercial aerosols containing chlorofluorocarbons (CFC), unstable compounds which are carried into the stratosphere, lead to significant and rapid ozone depletion.

The story revolves around a paper that Paul Crutzen (Nobel Prize winner for chemistry related to the CFC / ozone depletion link) has written about deliberately adding sulphate aerosols in the stratosphere to increase the albedo and cool the planet — analogous to the natural effects of volcanoes.

If the major emitters of greenhouse gases find it hard to agree on setting caps on emissions now, what makes you think the world can agree to injecting aerosols in the stratosphere as a solution?

During this period, the aerosol amount varied with dust export from Africa, but also from major eruptions by two volcanoes (El Chichon in 1982 and Pinatubo in 1991), each of which left a reflective layer of sulfate droplets in the lower stratosphere for a couple of years.

To elucidate human induced changes of aerosol load and composition in the atmosphere, a coupled aerosol and gas - phase chemistry transport model of the troposphere and lower stratosphere has been used.

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.