Sentences with phrase «stratospheric cloud»

Volcanoes don't inject significant chlorine into the stratosphere but they do increase small particles, which increase the amount of polar stratospheric clouds with which the human - made chlorine reacts.

Polar stratospheric clouds (PSCs) play a key role in stratospheric ozone depletion.

Those techniques have led to everything from the development of catalysts that remove poisonous carbon monoxide from car exhaust to the understanding of how ice crystals in stratospheric clouds supercharge atmospheric chlorine's ability to destroy the planet's protective ozone layer.

In both the past two winters, researchers saw polar stratospheric clouds over parts of Britain, said Jonathan Shanklin of the British Antarctic Survey.

The stable air that causes the ultra-cold conditions where polar stratospheric clouds form in Antarctica is much less likely.

Chlorine eats away at ozone, but only if light is present and if the atmosphere is cold enough to create polar stratospheric clouds on which chlorine chemistry can occur — a relationship that Solomon was first to characterize in 1986.

In September, the ozone hole is at its largest because the cold winter months coupled with the returning daylight permit stratospheric cloud formations that do the most damage to the ozone layer.

Regardless, the result is a satisfying full - circuit ride for Solomon, who in 1986 led the study that first identified stratospheric clouds as the chlorine reaction sites, and who played important roles in the scientific assessments for the Montreal Protocol and subsequent status reports.

«For a period of several weeks, wide areas of the Arctic were covered by polar stratospheric clouds between about 14 and 26 kilometers height.

«We were very much surprised to find polar stratospheric clouds down to heights of about 14 km,» Björn - Martin Sinnhuber says.

There are more polar stratospheric clouds observed now than ever before.

This results in more heat - trapping stratospheric clouds, and more hurricanes.

Dubbed «mother - of - pearl» clouds because of their attractive appearance, polar stratospheric clouds form at temperatures below -78 ° C.

At the surface of polar stratospheric clouds, chemical reactions take place, converting passive chlorine compounds into reactive compounds that trigger stratospheric ozone depletion.

The chemical reactions that break down ozone are particularly intense within cold, acidified clouds called polar stratospheric clouds.

An eerie «polar stratospheric cloud,» which destroys ozone at a rapid rate, hangs above Kiruna, Sweden, in January 2000.

That triggered vast polar stratospheric clouds, some of them as big as the continental United States.

Unfortunately, the three - oxygen atom of ozone is also highly reactive, and the conditions in the stratospheric clouds over the South Pole render it even more so.

Of particular importance are vertically extended polar stratospheric clouds that have been observed to cover wide areas of the Arctic.

On the basis of its intended flight route, the Perlan glider might be able to provide the first direct observations of polar stratospheric clouds, a unique type of ice cloud that forms in the polar stratosphere and helps to deplete ozone, Gong adds.

(Such low air temperatures encourage the formation of icy clouds in the upper atmosphere known as polar stratospheric clouds, which foster the chemical reactions that turn harmless chlorine compounds into ozone eradicators.)

The temperature of the stratosphere is one of the key factors in the springtime depletion of ozone above the Antarctic where in winter it gets colder than anywhere else on Earth, encouraging icy particles to form in polar stratospheric clouds.

Modelling has already shown that stratospheric clouds of sulphate particles could rapidly cool the planet.

Aircraft emissions probably play a crucial role in ozone destruction by fuelling the formation of polar stratospheric clouds.

THE world's highest - flying spy plane, the Russian M - 55, is about to give European scientists their first close - up view of the thin, stratospheric clouds that destroy ozone.

Research: reaction mechanisms and numerical simulation of atmospheric chemistry and transport; photochemistry of ozone and organic trace gases; polar stratospheric clouds and denitrification.

Particles composed of such hydrates are thought to be the principal component of the polar stratospheric clouds that initiate the destruction of ozone.

It normally reaches its widest extent in the southern hemisphere in the spring (August and September), as extreme cold temperatures in the stratosphere facilitate chemical reactions on the surface of polar stratospheric clouds.

We show that chemical loss of column ozone (Î O3) and the volume of Arctic vortex air cold enough to support the existence of polar stratospheric clouds (VPSC) both exceed levels found for any other Arctic winter during the past 40 years.

The interesting thing in the latest images is that the stratospheric clouds do not appear to be related to Thunderstorms, I wonder if this is due to uplift in the region of the Andes?

Subsequently it was shown variation was due to a combination of variation in UV, extremely cold temperatures, formation of polar stratospheric clouds (PSC) and intense atmospheric circulation.

Unusually low temperatures in the stratosphere, even cold records, are at fault — creating conditions whereby ice crystals form in so called polar stratospheric clouds.

A second factor is Polar Stratospheric Cloud (PSC) that form when gases including water vapor sublimate directly to crystals because of the intensely low temperatures -LRB--70 °C and below) and pressures over the South Pole.

It is caused by chemical reactions that take place primarily on the surface of polar stratospheric clouds, ice particles or liquid droplets which form at high altitudes in extreme cold.

Ozone holes are caused by chemical reactions that take place primarily on the surface of polar stratospheric clouds, ice particles, or liquid droplets, which form at high altitudes in the extreme cold of the polar regions.

But last year, Susan Solomon of MIT — who back in the 1980s became one of the world's most celebrated scientists for uncovering the chemistry of the polar stratospheric clouds — declared that she had detected the first «fingerprints» of the hole closing.

In the 1980s, Antarctic researchers discovered that these chemical reactions went into overdrive in the super-cold polar stratospheric clouds that formed over the frozen continent.

Solomon blamed 2015 on the Calbuco volcano in Chile, which ejected sulphur particles that enhanced the ozone - destroying properties of polar stratospheric clouds.

But it does happen whenever temperatures get cold enough for polar stratospheric clouds to form.