There’s nothing Southern California weather, with its nearly 300 days of sunshine. But here’s one teensy-tiny drawback to the cloudless skies and general lack of atmospheric commotion: The clearer and calmer the weather, the more we Angelenos hear the freeway. And the more we think about air pollution. Now, some people aren’t bothered by the sound of the freeway. I have a friend who claims to simply imagine that she lives closer to the beach and is hearing the distant sound of crashing waves. She says the constant flow of freeway traffic noise is easily tuned out. Except I can’t tune it out. I obsess over it. To me, the freeway…