What is Happening to the Bay Area's Fog and What Does it Mean for Local Berry Growers?

One of the things those of us in the berry business on the Central Coast take for granted and don't think much about is the fog.  I was recently approached by reporter Dana Cronin of KQED on this very subject and the result in this really interesting recent article on the changing quality of fog in our area.  While it does get into some larger themes, such as the fate of redwoods in a fogless environment and real estate tips, it does include some good science and a great interview with local grower Rod Koda.

In particular, my curiosity comes from my impression and those of others that have our fogs gotten lighter?  Back in the nineties when I'd go out to coastal fields, it was THICK, so thick in fact that you would just hear the pickers working and not see them, even if they were close.  That doesn't seem to happen as much, or does it?

Does all this about climate change have anything to do with it?  In other words, if it gets hotter and bakes the ocean, does that mean we get less fog, or is it the other way around that if there is more heat inland, does that mean we get more fog?

Getting into this subject, Dana quotes CSU Monterey Bay Environmental Studies Professor Daniel Fernandez as saying first you have to define what you mean by fog, which is sort of complicated.  Generally speaking, fog means that the air consists of water droplets between one and 50 microns (essentially it's a landfallen cloud), and there must be enough of these tiny droplets that impede our vision beyond a kilometer.

For this droplet formation and density to happen, says Dr. Fernandez, there must be a temperature gradient over a given area to be conducive to fog formation.  And yes we certainly have that gradient, with cool ocean air coming into contact with hot Central Valley air especially during the summer.  Again, just by having this gradient exist doesn't mean that fog will necessarily be formed, and it cannot be forecast the way rain is.  Naturally there is disagreement within the fog science community on what climate changes would actually mean in terms of fog formation

Dr. Fernandez has been monitoring intensity with a network of fog collectors all over the state, but these haven't been established long enough to make a determination up or down on the intensity of the fog we have been experiencing.  Still, he does say that we may be in for seeing less fog than a generation ago, and this is supported by some studies which show a decline of some 30% in summertime fog since the 1950's, but this could be because there is less dirt in the air from the cleanup of our cities so the opportunity for water droplets to form is lessened.  So you can see it's sort of a complicated question to answer at the moment.

To cover what fog means for the actual berry grower,  there's great interview with local grower Rod Koda, who lives within sight of the ocean south of Watsonville and obviously knows the pattern of fog.  Rod shares that he hasn't seen major changes in fog in the many (but not too many!) decades he's been farming there.  Fog is beneficial to him, he says the berries ripen slower and so take on a higher sugar content, not to mention that the heaviest production of fruit takes place during the biggest months of fog.

All in all, this a first class story by Dana Cronin of KQED about the fog we don't pay much attention to here on the coast, yet is something so integral to our agriculture and our way of life here.

In case you missed the hyperlink embedded in my summary above, it's here too:

Bay Curious: About Fog

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