9.Retell lecture (Cloud Formation)
Absolutely. There’s a lot of interest in what forms those clouds. Why are those clouds there, why do they stick around? At the center of every cloud drop is a particle. You can’t grow a cloud drop without having a particle there for the water to condense on. The key questions that people have not directly addressed until very recently is what actually forms those clouds. And so the ones that you’re looking at over the ocean, it turns out sea salt is a very effective nucleator for forming clouds,, so there’s a really good chance that those are loaded with sea salt. But as you go inland you start to have pollution come from all different kinds of sources, and so different sources form clouds more effectively than others. And we’re trying to unravel which sources are actually contributing to the clouds. The clouds are incredibly important players in climate change in that they reflect the light back to space, and so they’re keeping things much, much cooler than they would be if they weren’t there. They also play a huge role in regional weather. So we’re actually starting to see shifts where having more pollution input into the clouds is affecting weather patterns, and in particular it’s actually reducing the amount of precipitation, so we’re starting to see drought in areas with super high levels of air pollution.