Global Science Report is a feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”
A new paper has been published in the journal Geophysical Research Letters that examines trends in heavy rainfall amounts across the U.S. The paper is authored by Newcastle University’s Renaud Barbero and colleagues, and, to summarize, finds that the heaviest rainfall events of the year have been increasing in magnitude since 1951 when averaged across nearly 500 stations distributed across the U.S. (note: results from individual stations may differ from the general finding).
Someone with a critical eye might ask the real question, which is “how much?” That such a number does not jump out of this paper—a cynic would say—probably means it is very small. Read on and you will find the answer.
That rainfall on the rainiest day of the year is increasing is, of itself, hardly surprising considering that the total annual rainfall amount averaged across the U.S. has also been increasing during this same period (again, results from individual locations/regions may (and do) depart from this generality).
Changes in heavy rainfall like this are often luridly described as a “disproportionate increase” in extreme events, or that extreme precipitation increases are “worse than expected.”