Southern California Wildfires and Santa Ana Winds

The Santa Ana Winds are clearly evinced using an inadvertent smoke dye in the sky. These hot, dry winds are the cause of some of California’s — and the world’s — most costly wildfires (courtesy NASA/BBC).

I am a child of Southern California. Though I feel more out of place there than anywhere else in the world, it is the place of my birth. As a child I remember the falling ashes and the smoke-engulfed sky. I remember the floods and the Rodney King riots, and the Northridge earthquake.

This past weekend, I was down in Ventura visiting family. It was a bright, clear day. We went into the theater to catch Across the Universe, the new movie inspired by the music of the Beatles. As we exited the corridors of the theater everything seemed darker and more orange in hue.

I walked outside and ashes were falling like snowflakes. Tiny bits of burnt mesquite and tumbleweed floated through the sky. It never snows in Ventura, so the experience was all the more surreal.

It was only after listening to the radio for a few minutes that I realized the gravity of the situation. I could guess how severe the problem would be. I knew the fires would burn and continue burning; the previous night the news had announced the arrival of the Santa Ana winds, whose zephyrs of hell blow Westward, defying all logic about the proverbial “ocean breeze.” Raymond Chandler in “Red Wind” describes the winds eloquently:

Those hot dry winds that come down through the mountain passes and curl your hair and make your nerves jump and your skin itch. On nights like that every booze party ends in a fight. Meek little wives feel the edge of the carving knife and study their husbands’ necks. Anything can happen.

The Santa Ana’s hot, spine-tingling breeze comes from the East due to high pressure systems in the deserts. It’s a common misconception that these winds are heated by the desert, but the majority of the warmth is a result of adiabatic heating — the effect of air dumping from high altitudes into low altitudes; the subsequent compression of air causes it to warm up and expel any humidity.By the time these winds reach the California lowland coast, they’re bone-dry and they make you feel as if you’re walking on the face of Mars. They’re also the ideal winds for fires — and as they reached record levels above 75 mph last weekend, one could only guess what would follow.

A 2002 satellite image showing wind patterns. The red markers indicate Santa Ana patterns (courtesy NASA).

As of now, two have died, 1,200 homes and business are destroyed, a historic castle is in ruins, and 300,000 acres look like a mercurial firescape at this moment.

It is a uniquely geographic weather anomaly with devastating results. Why do people live in these places? Why are the most desirable home sites often the most disastrous? I only mean to pose the question. I have no answers.

Further Reading:

BBC News: California Santa Ana Fires
http://news.bbc.co.uk/2/hi/americas/7058809.stm

Wikipedia on Santa Ana Winds
http://en.wikipedia.org/wiki/Santa_ana_winds