There is a quality to the light here in the winter in Tucson that is incredibly beautiful and hard to photograph or even describe. I’ll try, though.

Part of its beauty is what it does to the mountains. In the summer, the light lands on us vertical, harsh, and direct, wiping out all contours or sense of three dimensions and makes the mountains look like Hollywood set backgrounds painted on a flat sky. In the winter it comes in bright and low from the south and brings out the shape of the mountains so you can see their depth.

More than that, however, there’s a cast to the color of the light that isn’t there in summer, a sort of blue steel tint. When a winter storm rolls in from the Pacific, the light shines on both the tops of the mountains and the bottoms of the clouds, making the entire horizon gleam like an unsheathed sword.

But when the skies are threatening rain, like today, it is more beautiful yet. The mist in the air filters the light, softens the contrasts, and, paradoxically, reveals the true distances of the far mountains by veiling them. The mist mixes the colors of the mountains, reflected browns and greens, with that steely light and creates a new light, a new look, that is familiar but which I couldn’t place until today.

Riding my motorcycle today through the desert, captivated by it, I suddenly recognized where I had seen it before: in underwater pictures taken in bright blue South Seas shallows. Saguaros like seaweed, clouds like surf foam, air like water, light brown sand like…well, light brown sand on the bottom of a bay, and I, two-wheeled, winding my way along the bottom like an eel, pensive and watchful.