Jupiter's great red spot heats planet's upper atmosphere
Researchers from Boston University's (BU) Center for Space Physics report today in Nature that Jupiter's Great Red Spot may provide the mysterious source of energy required to heat the planet's upper atmosphere to the unusually high values observed.
"With solar heating from above ruled out, we designed observations to map the heat distribution over the entire planet in search for any temperature anomalies that might yield clues as to where the energy is coming from," explained Dr. James O'Donoghue, research scientist at BU, and lead author of the study.
"We could see almost immediately that our maximum temperatures at high altitudes were above the Great Red Spot far below -- a weird coincidence or a major clue?" O'Donoghue added.
Bright regions at the poles result from auroral emissions; the contrast at low- and midlatitudes has
been enhanced for visibility. Great Red Spot (GRS) emissions at midlatitudes can be seen moving
under the slit from left to right. The vertical dark line in the middle of the image indicates the
position of the spectrometer slit which splits up the light from Jupiter like a prism. Image
shown is taken from the slit (slit-jaw imaging) using the "L-filter" (3.13 - 3.53 μm)
[Credit: James O’Donoghue, Luke Moore and NASA Infrared Telescope Facility (IRTF)]
Jupiter's Great Red Spot (GRS) is one of the marvels of our solar system. Discovered within years of Galileo's introduction of telescopic astronomy in the 17th Century, its swirling pattern of colorful gases is often called a "perpetual hurricane." The GRS has varied is size and color over the centuries, spans a distance equal to three earth-diameters, and has winds that take six days to complete one spin. Jupiter itself spins very quickly, completing one revolution in only ten hours.
"The Great Red Spot is a terrific source of energy to heat the upper atmosphere at Jupiter, but we had no prior evidence of its actual effects upon observed temperatures at high altitudes," explained Dr. Luke Moore, a study co-author and research scientist in the Center for Space Physics at BU.
"Energy transfer to the upper atmosphere from below has been simulated for planetary atmospheres, but not yet backed up by observations," O'Donoghue said. "The extremely high temperatures observed above the storm appear to be the 'smoking gun' of this energy transfer, indicating that planet-wide heating is a plausible explanation for the 'energy crisis.' "
Source: Boston University [July 27, 2016]