Caption: Rare cumulonimbus mammatus clouds hang low in the sky above a silhouetted view of Science Hall on the UW-Madison campus. Despite decades of research and increasingly sophisticated tools, cloud scientists are still struggling with one of the most basic issues of their field: how to define a cloud. Steven Ackerman, an atmospheric scientist at the University of Wisconsin-Madison, discusses the problem at the 2005 fall meeting of the American Geophysical Union.
Photo by: Jeff Miller
Date: April 2002
High-resolution 300 DPI JPEG