I've been told the the upper atmosphere has been shrinking, but I've heard recently that it's recovering, is it?
The upper atmosphere, specifically the thermosphere expands and contracts with the 11 year solar maximum and minum. During the minimum the temperature of the thermosphere cools and the it contracts. During a solar maximum the thermosphere expands as it heats up. The contraction that occurred during the last minimum was more than expected which is why it made the news. We are now in a solar maximum so the thermoshpere has expanded. We are moving to a minimum over the next couple of years so it will contract again. It is just a cycle that occurrs and nothing to be alarmed about. Thanks for bringing this up. I was not aware of this effect until I read up on it as a result of your post.
