Despite the dim Sun, Jupiter's atmosphere heats up to hundreds of degrees, thanks to the aurora borealis that never fades. Waves of abnormal heat quickly carry the heat further towards the equator.
When we look at Jupiter we can see its thick and powerful atmosphere, filled with swirling, colossal storms. The planet is fairly far from the Sun and receives less than four per cent of the radiation it receives at Earth's distance. From this, simulations predict the temperature of Jupiter's upper atmosphere to be around minus 70 degrees Celsius. But it is in fact much hotter, hundreds of degrees above zero in some areas. Scientists from the Japanese Space Agency (JAXA) have understood the reason for this phenomenon and presented their work at the Europlanet Annual Congress (EPSC) in Spain.
In 2021, speaking at the previous EPSC meeting, James O'Donoghue and his colleagues from JAXA unveiled temperature maps of Jupiter's upper atmosphere. Even then, the researchers speculated that auroras could be the source of their abnormal heating. This is how complex interactions between the planet's global magnetic field and the flow of charged particles coming from the Sun manifest themselves. Jupiter's magnetosphere is much more powerful than Earth's, so the auroras are much stronger there and never go out.
Now O'Donaghue and co-authors have confirmed the role of auroras in heating up the gas giant. Having carefully studied data on the temperature of Jupiter's upper atmosphere, scientists discovered that in the vicinity of the auroras it reaches 700 degrees Celsius, and then the winds carry the red-hot gases towards the equator. This process takes place continuously but at certain moments is dramatically intensified. Because of the particularly violent interactions of solar plasma with the planet's magnetosphere, powerful waves of heat waves are generated in the atmosphere and propagate rapidly away from the poles.
Scientists have tracked one such wave, which moved from the north, reaching speeds of thousands of kilometres per hour and a width of 130,000 kilometres - an order of magnitude larger than the diameter of the Earth. Thus, heat generated in Jupiter's upper atmosphere by solar plasma heats it to high temperatures. This heat is rapidly distributed towards the equatorial regions, with the process sometimes further amplified by anomalous heat waves reaching truly Jupiterian proportions.
