NASA to study atmospheric storms that disrupt satellites

Washington: A NASA-funded sounding rocket mission will help better understand and predict the electrical storms in Earth`s upper atmosphere, which can interfere with satellite communication and global positioning signals.

The mission, called Equatorial Vortex Experiment (EVEX) will launch two rockets for a twelve-minute journey through the equatorial ionosphere from an atoll in the Pacific in the next few weeks. The launch window for the mission from the Kwajalein Atoll in the Marshall Islands is from April 27 to May 10, 2013. The ionosphere is a crucial layer of charged particles surrounding our planet. This layer serves as the medium through which high frequency radio waves such as those sent down to the ground by GPS satellites or any satellite communicating with Earth travel. The ionosphere begins about 96.5 km above the ground and is filled with electrons and ions, alongside the more familiar extension of our electrically neutral atmosphere. Governed by Earth`s magnetic field, high-altitude winds, and incoming material and energy from the Sun, the ionosphere can be calm in certain places or times of day, and quite turbulent at others. This area of the ionosphere is known for calm days and tempestuous nights, times when the ionosphere becomes rippled like a funhouse mirror, disturbing radio signals, and introducing GPS errors of a half mile or more. The two rockets will measure events in two separate regions of the ionosphere to see how they work together to drive the ionosphere from placid and smooth to violently disturbed. Such information could ultimately lead to the ability to accurately forecast this important aspect of space weather. "We`re looking at the two highest regions of the equatorial ionosphere, called the E and F regions," said Erhan Kudeki, the principal investigator for the mission at the University of Illinois in Urbana-Champaign. "Violent ionospheric storms can occur in the equatorial F-region a few hours after sunset and if we can better understand what causes these storms, we`ll be able to better mitigate their effects on communication and navigation systems," Kudeki said. The mission team will wait for the first signs of turbulence developing before launching both rockets. The research goal is to study whether turbulence at sunset in the E-region of the ionosphere could serve as a warning of storms in the higher F-region an hour or two later. PTI