Researchers from Los Alamos National Laboratory and other institutions today reported in Science magazine the first measurements of one way that happens. Plasmas from Earth and the sun are trapped and flow along Earth's magnetic field lines, or magnetosphere, and make up such spectacular electrical phenomena as auroras. The research team proved that the polar wind is one mechanism by which the atomic constituents of water vapor and other atmospheric gases are dragged outward from the ionosphere and spiral along the planet's magnetic field lines.
Sunlight breaks the water into ionized hydrogen and oxygen gases in the upper atmosphere.
This gives us a look at the cutting edge of atmospheric evolution and the dynamic way material flows from Earth into space, contributing significantly to Earth's space weather. The flow of charged gases from Earth is extremely diffuse and hard to detect. To complicate matters, previous space instruments couldn't get accurate readings due to electrical interference from the spacecraft that carried them. When photons from the sun strike spacecraft, they drive off electrons and give the entire craft a slight positive charge, which keeps positively charged gases from reaching the craft and its measuring instruments. The TIDE instrument has seven large apertures that give it high sensitivity in identifying and measuring charged hydrogen, helium, oxygen and other heavier ions from the ionosphere, along with helium from the solar wind.