In a nice piece in the Ventura County Star by Zeke Barlow, the oceanographer and climatologist Bill Patzert points out a good aspect of the Zaca Fire: some of the sunsets we’ve been seeing.
He explains why they look the way they do:
The bright color is light bouncing off smoke and ash particles. The
more particles, the more colorful the sky. Friday had 58 micrograms of
particulate matter per cubic meter in Ojai. A moderate level is less
than 40; a normal level is around 15.
The current levels aren’t terribly good for you, but they sure are pretty. Sort of like birthday cake.
Size matters, too. The larger the particle, such as chunks of ash,
the more oranges and reds will scatter across the horizon, because they
have longer wavelengths than other colors, said Bill Patzert, a
climatologist with the Jet Propulsion Laboratory.
Patzert said dynamic sunsets also provide better chances to witness
the elusive green flash, a burst of light just after sunset. The green
wavelengths are bent, coming around the horizon after the sun has sunk,
creating an optical illusion.
Jules Verne wrote about it in "Le Rayon Vert." He said you can peer into someone’s soul when you witness it.
My grandfather Frederick Brooks, a UC Davis engineer and meterologist fascinated with the microclimates of Northern California, also described the "green flash" in longing tones. I think he had seen one; I confess I have not, despite having seen many another sunset.
But how can you peer into someone’s soul, if you’re looking off into the sunset?
(Here’s a recent local sunset, courtesy of John Mueller via Creative Commons.)
One thought on “A Fiery Gift”
I don’t know about peering into the soul, but in some locations it’s not that hard to see the green flash, and you might be in luck! I saw it many times during the year that I lived in San Diego. We would see it when there was very cold air over relatively warm water, like during a winter time cold-air outbreak. After a strong cold front, when the air is really cold and clear, just go down to the ocean right before sunset and hope that there are no clouds on the horizon. It lasts only a moment or two, and it’s a pretty subtle feature, not nearly as grand as the name would imply! I never saw one in N. Calif. because I don’t think the water is quite warm enough to give you the air-sea temperature contrast you need, but it just might be warm enough in Ventura. I disagree with Patzert, however: the smoke makes it LESS likely to see a green flash, because it scatters away the blue, green and even yellow wavelengths—that’s why the sun appears redder.