His science interests include cloud physics, precipitation processes, radar meteorology, lightning and satellite remote sensing. Dr. Petersen is a Fellow of the American Meteorological Society and an accomplished field scientist, having served as the NASA Lead PI for a large number of combined airborne and ground-based field campaigns including MC3E, GCPEX, LPVEX, IFloodS, IPHEx and OLYMPEX, and participated as a radar scientist in campaigns such as TRMM-LBA, STEPS, EPIC-2001, and TOGA COARE.