Marcel G. Schaap is currently an assistant professor in environmental physics at the University of Arizona’s Department of Soil, Water and Environmental Science. Previously he has worked as an assistant/associate professional research scientist at the University of California, Riverside; a cooperative employee at the George E. Brown Jr. Salinity Laboratory (USDA-ARS) in Riverside: and as a postdoctoral researcher at the University of California, Riverside. Schaap holds a B.A. in chemistry, an M.S. in physical geography, and a Ph.D. in environmental sciences from the University of Amsterdam in the Netherlands. .