In a public relations push punctuated by a continual stream of roaring jet aircraft, the Marine Corps opened Miramar Air Station yesterday to bolster its campaign against the notion of a civilian airfield. “Joint use is fundamentally incompatible with what we do,” said Maj. Gen. Michael R. Lehnert, commander of Marine Corps Installations West. “It's simply a function of physics, and you cannot repeal the laws of physics.” The air base conducted a guided tour for reporters three days before the expected vote by the San Diego County Regional Airport Authority board on a future replacement for Lindbergh Field. Despite...