Tuesday, February 14, 2012

The start of upwelling season

It's good to have a nemesis...isn't it?  It keeps you alert, on your toes, ever watchful.  The Oxford English Dictionary describes a nemesis as a "persistent tormentor".  I suppose I have lots of photographic nemeses, but upwelling is at the top of the list.

At Bodega Head, the upwelling season often begins in February, and this week is showing hints of this wind-intense time of year.  Northwest winds have been blowing at 15-25 knots (with gusts over 30 knots) since Sunday.  It looks like it will continue through at least Wednesday, and similar winds are forecast for the weekend.

Upwelling: the rising of bottom waters to replace surface waters that have been driven offshore by strong winds and the Coriolis effect.  This leads to cold, nutrient-rich water near shore and very high biological productivity.  An awareness and appreciation of upwelling is critical to understanding life on Bodega Head, but therein lies my dilemma.  How do you represent upwelling in a photograph?

When you search for images of upwelling online, the results are dominated by diagrams and remote sensing images.  But what does upwelling look like when you're standing on shore looking at the ocean?

Maybe a photograph isn't the best way to represent upwelling.  It might be better to stand in a wind tunnel, or to try keeping your hand submerged in 8-9°C water (without grimacing), or to attempt to count the number of species that are influenced by upwelling (instead of counting sheep?).  But I can't seem to let go of the photographic challenge.  I didn't accomplish the goal today, but here are a few photos primarily of the foam that develops and becomes airborne during strong upwelling conditions.





Below, can you tell which way the wind is blowing — right to left, or left to right?


The wind is pushing the foam across the water from right to left.  Note the wind acting on the foam creates small parabolas, with heads to the left and tails, or trailing ridges, behind.

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