How to track down why Wi-Fi random disconnects on one particular network?

For starters you could try a simple ping to a popular outside URL, like yahoo.com or google.com, let it run like 10-15 times, maybe more, and see if the connection gets no response in any of the pings. That will show you your connection on that network isn't consistent.

There are also various Wi-Fi network optimization settings, so something that benefits them the most in crowded areas may not be working for your machine. If they are testing newer Wi-Fi frequencies, like AC or even some variant of N, you may not be the only person affected with a new MacBook on campus.