On a cold winter’s night the moisture in the atmosphere has frozen, and ice crystals are drifting slowly downwards from the sky. Where they encounter lights pointing upwards, the stream of falling crystals is picked out as though in the beam of a searchlight.
storms originating in the Sahara Desert produce stunning aerial photos with
plumes of particles observed being blown to Europe and even as far as South
America. Saharan dust storms have increased 10-fold during the last 50 years.
Land degradation due to agriculture has increased the amount of dust particles
that can be caught up in the winds propelling them across to all these other
continents. The question now is whether dust storms will be ever more common as
we continue trying to meet the demand for food.
credit: Sahara stof by SeaWiFS Project, NASA/Goddard Space Flight Center and
ORBIMAGE. Public domain via Wikimedia
A whopping 97 percent of all the Earth’s water sits in the oceans, 2 percent is frozen in glaciers and ice sheets, and less than 1 percent flows in streams, lakes, and as groundwater. Only 0.001 percent of the planet’s water is in the atmosphere at any one time, and yet it serves as the key to the movement of our atmosphere and the world’s weather.
Patricia Barnes-Svarney, Thomas E. Svarney, “Skies of Fury”
This photo shows a supercell thunderstorm that swept across west Texas a few years ago. The photo was taken near the town of Ballinger, where the storm dumped hail up to the size of tennis balls and produced strong winds that damaged trees and power poles.
A thunderstorm is classified as a supercell storm if it contains a persistent rotating updraft, or mesocyclone. Supercell storms are responsible for some of the most intense severe weather, including tornadoes, very large hail, damaging winds, and floods.
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.”
Gas “fingerprinting” could help energy industry manage CO2 storage
A new technique for monitoring carbon dioxide could help the energy industry’s efforts to reduce future greenhouse gas emissions, scientists have found.
In a new paper published in the International Journal of Greenhouse Gas Control, researchers describe how they have used the unique signature from traces of the noble gases (helium, neon and argon) to monitor the fate of carbon dioxide stored underground.