Press Release
TIMED Celebrates 5-Year Anniversary: Several AGU Sessions Showcase Mission Accomplishments
This image obtained by the TIMED Global Ultraviolet Imager β the only NASA instrument currently imaging the Earth's aurora and upper atmosphere from space β shows an aurora, superimposed over an Earth image, produced by a major geomagnetic storm that occurred on April 14, 2006. The solar storm occurred during solar minimum, the least active part of the 11-year solar cycle, which was once considered to be the time when scientists could measure the "baseline" or quiescent state of the upper atmosphere.
But as this image shows, major storms can still occur during such "quiet" times. The April 14th storm occurred due to changes in the geomagnetic field produced by a co-rotating interaction region that propagated out from the sun. The impact of this storm was seen in disturbed conditions in the Earth's upper atmosphere and ionosphere, and over the continental United States.
TIMED's systematic global measurements of the upper atmosphere show that the atmosphere is continually subjected to solar-induced disturbances leading scientists to ask whether there truly is a quiescent state of the upper atmosphere.
Credit: Johns Hopkins APL
NASA's TIMED (Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics) mission, operated by The Johns Hopkins University Applied Physics Laboratory (APL), celebrated its 5th launch anniversary on Dec. 7, 2006, and its many contributions enabling a greater understanding of Earth's upper atmosphere. Several sessions at the fall 2006 American Geophysical Union conference in San Francisco, Calif., Dec. 11-15, are showcasing TIMED observations and how this mission, in coordination with a network of space- and ground-based systems, has provided the first view of the mesosphere, ionosphere and thermosphere as a coupled system throughout a range of solar activity levels.
TIMED was launched on Dec. 7, 2001, during solar maximum (the busiest period during the 11-year cycle of solar activity) and has collected data through the declining phase and into solar minimum. "One of TIMED's main science goals is to understand the energetics of the ionosphere, thermosphere and mesosphere region," says Sam Yee, TIMED project scientist from APL.
Originally a 2-year mission, TIMED has been extended for the second time since its launch, with operations and data analysis continuing through 2010. TIMED's continued study of solar effects on our atmosphere will also help set the stage for future NASA Heliophysics missions, such as those within its Living With a Star program that focus on better understanding the sun's effects on life and society.
"TIMED has served as a catalyst for a greater understanding of our thermosphere and ionosphere," says Dr. Larry Paxton, APL's project scientist for TIMED's Global Ultraviolet Imager (GUVI). "It exists at a time of unprecedented resources such as NASA's Heliophysics Great Observatory (a collection of NASA's sun-Earth-focused missions, which includes TIMED) and an extensive international ground-based instrument network," he says. "TIMED has shown that a low-cost mission can make a contribution to our understanding of the global ionosphere-thermosphere system."
TIMED's long-term study of our middle and upper atmosphere (the mesosphere and lower thermosphere/ionosphere) will help scientists better understand this atmospheric region's variability and its effects on communications, satellite tracking, spacecraft lifetimes, degradation of spacecraft materials, and on the reentry of piloted vehicles.
Since launch TIMED has collected various measurements showing how different parts of Earth's atmosphere reacts to an array of solar activity, including a total solar eclipse in spring 2006 (see full story at /PressRelease/060524b).
TIMED data has also shown similarities between the atmospheres of Earth and Mars when compared to ionospheric data sets acquired in 2003 by NASA's Mars Global Surveyor (/PressRelease/060524c.asp).
In 2004 TIMED captured a glimpse of an auroral display that dipped as far south as Alabama (). It recorded our atmosphere's response, in 2003, to some of the largest geomagnetic storms on record (). And in 2002, TIMED observed our atmosphere's response to a series of strong solar storms, providing important new information on the final link in the Sun-Earth Connection (SEC) chain of physical processes connecting the sun and Earth.
NASA Goddard Space Flight Center manages the TIMED mission. APL, in Laurel, Md., leads the project's science effort and manages the mission's Science Data Center.
For more information, visit .
TIMED at AGU
TIMED will be highlighted in the following aeronomy sessions during the fall AGU meeting:
Tues., Dec. 12:
- Session SA21A β ITM System from Solar Maximum to Solar Minimum: Recent Progress in Aeronomy II (Posters)
- Session SA23A β ITM System from Solar Maximum to Solar Minimum: Recent Progress in Aeronomy III
- Session SA24A β ITM System from Solar Maximum to Solar Minimum: Recent Progress in Aeronomy IV
Wed., Dec. 13:
- Session SA31A β ITM System from Solar Maximum to Solar Minimum: Recent Progress in Aeronomy V
For details on these sessions, please visit . To search for other related sessions, please visit AGU's Web site at , and click on "scientific program."