* Astronomy

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RE: Earth's atmosphere

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The basement solves an oxygen puzzle

The Earth's atmosphere did not become rich in oxygen in a single event, but through a series of episodes spread over hundreds of millions of years. This is the opinion of geoscientists who have studied rock cores from the basement in northwestern Russia.
The discoveries were made by an international research group and have been published jointly in Science by, among others, NGU geoscientists Victor Melezhik, Aivo Lepland and Alenka Crne. The work forms part of an international project, the Fennoscandia Arctic Russia - Drilling Early Earth Project (FAR DEEP).
The fieldwork took place over five months on the Kola Peninsula and in Karelia in 2007. Cores were drilled into basement rocks spanning an unbelievably long period from 2440 million to 2000 million years.
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Oldest minerals trace early Earth's atmosphere

In a new study funded by NASA, scientists have used the oldest minerals on Earth to reconstruct the atmospheric conditions present on Earth very soon after its birth.
The study, conducted by researchers at the New York Centre for Astrobiology at Rensselaer Polytechnic Institute, is the first direct evidence of what the ancient atmosphere of the planet was like soon after its formation and directly challenge years of research on the type of atmosphere out of which life arose on the planet.
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Earth's evolution 'all about gas'

Planetary scientists claim to have provided new insights into the processes behind the evolution of Earth by demonstrating how salty water and gases transfer from the atmosphere into our planet's interior.
It has long been argued about how the Earth evolved from a primitive state in which it was covered by ocean of molten rock into the planet we live on today with a solid crust made of moving tectonic plates, oceans and an atmosphere.
Now, an international team, led by Dr Mark Kendrick at the University of Melbourne, has shown that atmospheric gases are mixed into the mantle, inside the Earth's interior, during the process called "subduction" when tectonic plates collide and submerge beneath volcanoes in subduction zones.

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How hot did Earth get in the past?

The question seems simple enough: What happens to the Earth's temperature when atmospheric carbon dioxide levels increase? The answer is elusive. However, clues are hidden in the fossil record. A new study by researchers from Syracuse and Yale universities provides a much clearer picture of the Earth's temperature approximately 50 million years ago when CO2 concentrations were higher than today. The results may shed light on what to expect in the future if CO2 levels keep rising.
The study, which for the first time compared multiple geochemical and temperature proxies to determine mean annual and seasonal temperatures, is published online in the journal Geology, the premier publication of the Geological Society of America, and is forthcoming in print Aug. 1.
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JPL Airborne Sensor to Study 'Rivers in the Sky'

They're called atmospheric rivers - narrow regions in Earth's atmosphere that transport enormous amounts of water vapor across the Pacific or other regions. Aptly nicknamed "rivers in the sky," they can transport enough water vapour in one day, on average, to flood an area the size of Maryland 0.3 meters deep, or about seven times the average daily flow of water from the Mississippi River into the Gulf of Mexico. The phenomenon was the subject of a recent major emergency preparedness scenario led by the U.S. Geological Survey, "ARkStorm," which focused on the possibility of a series of strong atmospheric rivers striking California - a scenario of flooding, wind and mudslides the USGS said could cause damages exceeding those of Hurricane Katrina in 2005.
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Ionosphere F-region

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Earth's Atmosphere

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Earth's upper atmosphere cooling dramatically

When the sun is relatively inactive - as it has been in recent years - the outermost layer of Earth's atmosphere cools dramatically, new observations find.
The results could help scientists better understand the swelling and shrinking of our planet's atmosphere, a phenomenon that affects the orbits of satellites and space junk.
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Scientists discover surprise in Earth's upper atmosphere
UCLA atmospheric scientists have discovered a previously unknown basic mode of energy transfer from the solar wind to the Earth's magnetosphere. The research, federally funded by the National Science Foundation, could improve the safety and reliability of spacecraft that operate in the upper atmosphere.

"It's like something else is heating the atmosphere besides the sun. This discovery is like finding it got hotter when the sun went down" - Larry Lyons, UCLA professor of atmospheric and oceanic sciences and a co-author of the research, which is in press in two companion papers in the Journal of Geophysical Research.

The sun, in addition to emitting radiation, emits a stream of ionised particles called the solar wind that affects the Earth and other planets in the solar system. The solar wind, which carries the particles from the sun's magnetic field, known as the interplanetary magnetic field, takes about three or four days to reach the Earth. When the charged electrical particles approach the Earth, they carve out a highly magnetized region - the magnetosphere - which surrounds and protects the Earth.
Charged particles carry currents, which cause significant modifications in the Earth's magnetosphere. This region is where communications spacecraft operate and where the energy releases in space known as substorms wreak havoc on satellites, power grids and communications systems.
The rate at which the solar wind transfers energy to the magnetosphere can vary widely, but what determines the rate of energy transfer is unclear.

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