More and more satellite clouds are spinning the Earth, which may be more than just a chaotic night sky. New research suggests that an increase in the frequency of satellite reentry may significantly affect our atmosphere, possibly changing the stratosphere temperature and affecting the ozone layer.
Scientists from the National Oceanic and Atmospheric Administration (NOAA) published a discovery in the Journal of Geophysical Research, examining how alumina particles released during satellite reentry accumulate in the atmosphere. Their model predicts that by 2040, when the number of satellites may exceed 60,000, the mass of artificial materials entering our atmosphere may compete with natural dust.
“This will result in annual emissions of artificial materials being discharged into the upper atmosphere in the same order of naturally occurring meteorite emissions,” the researchers noted in their study.
The research team led by Christopher Maloney simulated different reentry scenarios based on the expected satellite population growth. Since aluminum accounts for about 35% of the mass of a typical satellite, they are particularly concerned with alumina.
According to their findings, these particles will not simply be scattered. Instead, they accumulate in specific areas of the atmosphere, mainly at high latitudes between 10 and 30 kilometers on the surface of the ground. Simulations show that these particles can reach heights containing our protective ozone layer within 1-3 years, depending on where the satellite re-enters.
Although the direct warming effect of these particles is relatively small, the researchers found that in the middle atmosphere at high latitudes, they may trigger temperature anomalies up to 1.5 kelvin. Perhaps most surprisingly, these temperature changes may affect wind patterns in polar vortices, which in some cases may lead to “weaker ozone pores in spring.”
The researchers tested five different reentry scenarios, including controlled reentry to specific areas and uncontrolled reentry from various tracks. An interesting finding is that the effects of polar reentry appear to be less than those of the equator, where particles travel faster throughout the atmosphere.
The study’s co-author Dr. Karen Rosenlof emphasized that the study represents only the initial findings. “This initial modeling study is the first step in a process-based approach that can understand the potential climate impacts of the expected increase in satellite reentry mass flux,” the researchers wrote.
The team acknowledged some limitations in their research. They have not yet modeled how these alumina particles interact with the stratosphere chemically or how they might affect cloud formation if they eventually descend into the lower atmosphere.
As space becomes increasingly commercialized, it becomes even more urgent to understand these atmospheric effects as SpaceX and others launch companies with thousands of satellites. The study predicts that annual satellite reincome emissions could reach 10,000 metric tons by 2040 – conservative compared to some estimates.
“Currently, the impact on the middle and upper atmosphere is small, but there is a possibility of increasing possibilities,” the researchers concluded. Call for augmented observations and modeling efforts to better understand how our growing space activity might change Earth’s protective envelope.
If our report has been informed or inspired, please consider donating. No matter how big or small, every contribution allows us to continue to deliver accurate, engaging and trustworthy scientific and medical news. Independent news takes time, energy and resources – your support ensures that we can continue to reveal the stories that matter most to you.
Join us to make knowledge accessible and impactful. Thank you for standing with us!
