Beginning 80 kilometres above Earth’s surface, and extending to the edge of the atmosphere, the thermosphere occupies a large proportion of Earth’s upper atmosphere. So far, studies of this expansive region have largely focused on how the air it contains flows over global scales. Now, Dr Ying Zou at the University of Alabama in Huntsville has explored how the thermosphere is also significantly influenced by ‘mesoscale’ interactions with Earth’s magnetosphere, creating flows spanning just hundreds of kilometres. Her team’s work could greatly improve our knowledge of how the upper atmosphere behaves.