Sentences with word «nacreous»

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).

The mantle of the animal coats the irritant with many layers of nacreous material to reduce irritation, until the pearl is formed.

They are called nacreous clouds and noc - tilucent clouds.

Regions of nearly complete ozone depletion, which have occurred in the Antarctic during the spring, are associated with nacreous clouds, chlorofluorocarbons (CFCs), and other pollutants from human activities.

These might look a little like the northern lights, but they are, in fact, an utterly different atmospheric phenomenon known as nacreous clouds.

Light Column, 1970, a transparent, three - pointed, star - shaped column, reflects iridescent shadows along its interior sections; on the wall, Untitled, 1966 — 67, a wide aluminum circle sprayed with acrylic lacquer, emanates nacreous vibrations, projecting four circular shadows behind itself, as perfect as if they were painted on the wall.

A black coloured top - layer spray checks everything back into a fictive uncertain illusory space which, allied with new nacreous and interference pigments, has the added quality of opulence.

HTC has opted for a «liquid surface» which basically amounts to a vaguely nacreous finish reminiscent of mother - of - pearl.

Imposing Chanel chain necklace from Les Métiers d'Art «Paris - Edinburgh» multi rows in black, smoky gray and beige tweed, a row of nacreous and smoky gray glass pearls.

The infrequent clouds that do occur are called nacreous, or mother - of - pearl, clouds because of their striking iridescence, and they appear to be composed of both ice and supercooled water.

10 Unfortunately, nacreous clouds also support chemical reactions that convert benign chlorine - containing molecules into a form that destroys Earth's ozone layer.

Nacreous clouds are not rare, but they are seldom witnessed outside polar regions.

9 Nacreous clouds, or «mother of pearl» clouds, appear iridescent because of their ultrafine ice crystals, which form 10 to 15 miles up in the stratosphere.

What role the proteins play during growth had not previously been explained, but the assumption was that several proteins acted together to control the structure of the calcium carbonate lattice as well as themselves forming part of the nacreous layers.

And the same idea is amplified by the glimpse of the back of another painting installed outside one window, which materialises through the nacreous layer.

The next flight was along the same route, one or two days later, and the nacreous cloud had gone but, in the same general area, there were noctilucent clouds shining in the light of an invisible sun, much higher, certainly well over 100,000 ft. I've often wondered if the conventional explanations of noctilucent clouds are right.

Back in the late 60s I was out at about 18W over the Atlantic and saw, for the first and last time, a nacreous cloud, up around 70 to 80 thousand feet, nearly twice our cruising altitude.

Nacreous clouds occur at altitudes of about 20 miles, and noctilucent clouds at altitudes of about 50 miles.

Nacreous and Noctilucent Clouds.