Making anglo North Americans even more paranoid and racist, getting them hyped for a war with China? Distract people from actually terrible things like the poisoned town in Ohio, increasing effects of climate change, our bleak present and even bleaker future? Is China just trolling the US and Canada? Aliens? What is going on lol
I'm sure their science advisors told them. This arctic blast event is a once-in-a-generation event so a lot of scientists are throwing up balloons to get direct observations. They also know this arctic blast event started in China so having a balloon come through is not unexpected at all.