Polar stratospheric clouds (PSCs) form in the stratosphere at altitudes of 50,000–80,000 ft. They are classified into Types I (clouds with more diffuse and less bright colors) and II (nacreous or mother-of-pearl clouds), according to their formation temperature and particle size. Unfortunately, Polar stratospheric clouds play a key role in the massive ozone depletion over the Arctic and Antarctic. NASA explains that PSCs “form only at very low temperatures. They help destroy ozone in two ways: they provide a surface which converts benign forms of chlorine into reactive, ozone-destroying forms, and they remove nitrogen compounds that moderate the destructive impact of chlorine. In recent years, the atmosphere above the Arctic has been colder than usual, and polar stratospheric clouds have lasted into the spring. As a result, ozone levels have been decreasing.”
Photo: NAT GEO
Reblogging this because I’m currently revising Environmental Chemistry and the London smog is in it.
Insufficient combustion of fuel… Sulfur impurities in coal… Yes.(via seearr)
رَبِّ ارْحَمْهُمَا كَمَا رَبَّيَانِي صَغِيرًا
(Rab-bir ham-hoo-ma ka-ma rabba ya-nee sa-ghee-ra)My Lord! Have mercy on them both as they did care for me when I was little.
It’s in the Quran, Surat Isra (17:24).
(Source: subhanallah, via keeping-it-halal)