According to a just-released study by UC Berkeley researchers, based primarily on airport cloudbank measurements, fog in summer is less prevalent in Northern California over the last hundred years, down by about a third, which could threaten the beautiful, iconic redwoods of the northern California Coast.
A couple of qualifications; first, as the new study by James Johnstone and Todd Dawson notes, this does not match results from all the previous research. Work by Robert Bornstein's team at San Jose State found more wind and fog in the summer along the California coast in the last thirty years. Their argument is that more anthropogenic heat in the hotter interior regions of the state leads to a bigger thermal low, thus pulling more ocean air and more wind and fog across the coastal mountains.
Johnstone and Dawson. by contrast, link the decline in fog to the Pacific Decadal Oscillation.
Second, the trend looks alarming over the last century, but over the last fifty years it's not so evident, and (unlike, for instance, the decline in arctic ice). Interestingly, the fog levels look today not so different from those of the l950's, when the PDO was also negative, as it is now.
Nonetheless, for those of us who love redwoods, this is troubling news.
Redwoods are to fog as fish are to the sea…