Pacifica Radio’s new executive director, effective tomorrow, is Arlene Engelhardt, a programmer and former board president at affiliate station WMNF in Tampa. She was appointed by the Pacifica Foundation’s national board last week, succeeding Grace Aaron, the board chair who has served as interim director since January. The top staff position has been open since the resignation of Nicole Sawaya in September 2008. Engelhardt is co-host of Women’s Show, “an eclectic feminist/womanist radio magazine” on the Tampa community radio station. She has been a peace activist, an executive with United Cerebral Palsy and a v.p. of product development for a multimedia publishing company, according to Pacifica. The often-fractious, politically progressive five-station chain and national network based in Berkeley, Calif., celebrated its 60th anniversary in April.