The investigators are exposing university faculty and students to the interdisciplinary nature of interactions among the geosphere, hydrosphere, cyrosphere, and biosphere, and their policy impact. This Earth System Science Program will provide a Research Experiences for Undergraduates site, selecting 10 undergraduate students each summer. Summer activities, which complement the existing ESS Program, involve data analysis and modeling activities focusing on the effect of atmospheric aerosols and trace gases on solar radiation at or near Earth's surface. Students will attend a series of ESS lectures, discuss critical thinking across scientific disciplines, train in scientific writing, and develop oral presentations.