During World War II, Penn State's Department of Meteorology was recognized for its excellent training program. The Korean War forced the United States Air Force to recognize the need for officers with meteorological training. In1951 the U.S. Air Force began sending about twenty-five students each year to Penn State. This infusion of professional students helped the undergraduate enrollment to reach a critical mass for the first time. Dr. Alfred K. Blackadar (Emeritus) evaluates the importance of these students: "If it hadn't been for the Air Force program, we would not have been able to support the faculty and course instruction level we were giving at the time." Now, quality students are coming from the PSU ROTC program, while graduate students are still coming from the U.S. Air Force. All of these students are considered important because they are mature, carefully selected and set a high standard for the total student body to follow.