NASA and NOAA scientists forecast the next solar maximum to occur in 2025.
As the “solar maximum” approaches, satellites sing, “its getting hot in here.” Significant atmospheric temperature increases due to a string of geomagnetic storms hint at the looming “solar maximum.” This could cause trouble for Earth-orbiting satellites in the coming years. And this is important because we need to understand better how space weather works for us to better prepare our future satellites and spacecraft for space exploration. But how do we measure temperature in space?
“Solar Maximum” and How NASA Measures Thermospheric Temperature
The thermosphere, extending roughly 85 kilometers from the ground up to 600 kilometers above, is the gatekeeper to outer space. NASA has tracked its temperature for over two decades, through infrared emissions from carbon dioxide and nitric oxide. Using the TIMED satellite, scientists transform the collected data into the Thermosphere Climate Index (TCI), gauged in terawatts (TW).
“On March 10, TCI reached a peak at 0.24 TW,” shared Martin Mlynczak, the TIMED mission’s lead investigator at NASA Langley Research Center in Virginia, adding that the last time the index was this high was in late December 2003.
Geomagnetic Storms Stir Up the Thermosphere
As explained by Space Weather, the recent temperature rise was triggered by three geomagnetic storms in January and February. These large disturbances in Earth’s magnetic field, propelled by solar wind and magnetized plasma (CMEs), release their energy into the thermosphere, leading to significant heating, Mlynczak explained.
“Typically, post-storm infrared emissions cool the thermosphere. But when storms hit back-to-back, the temperature remains elevated,” he added. Since the peak, two more storms have struck Earth, one on March 24 and another on April 24, equally potent and marking the most intense solar storms in over six years.
Implications of the Solar Maximum
Geomagnetic storms intensify and become more frequent during the solar maximum, an 11-year cycle when the Sun is most active. This, in turn, leads to the thermosphere following a similar cycle.
NASA and NOAA scientists forecast the next solar maximum to occur in 2025. This suggests the thermospheric warming trend will continue for several more years. “Changes in the thermosphere could affect low-Earth-orbiting satellites at the upper thermospheric limit,” Mlynczak warned.
As the thermosphere expands due to warming, satellites experience increased drag, bringing them closer to Earth. This can potentially lead to satellite collisions or falling out of orbit entirely, as occurred with the SpaceX Starlink satellites in February 2022.
An earlier-than-expected solar maximum is also possible. A recent study published in the journal Frontiers in Astronomy and Space Sciences predicts the peak of solar activity could occur in late 2023 and be more intense than anticipated, increasing the risk of a satellite disaster.
Have something to add? Visit Curiosmos on Facebook. Join the discussion in our mobile Telegram group.
