Tuesday, September 25, 2012

Penetrating the Mysteries of Fog

By Tom Greco

Anyone who has spent more than a few days in the Bay Area knows that fog is an iconic feature of the region. In the late afternoon you can often see it welling up over the ocean and beginning to roll in. By the evening many areas remain blanketed by its cool embrace until the heat of the morning sun burns it away. Fog tends to follow different flow patterns in each of the unique geographies of our area but no matter where it occurs you can be sure that it carries cool air and moisture and as a result plays an integral part in the function of our ecosystems.

Morning fog in front of the Dwight Center
The redwoods of the California coast, for example, are dependent on fog for moisture during the dry summer months of our Mediterranean climate. Their foliage even shows signs of adaptation specifically to increase capture and absorption of moisture in the air. A study conducted by Emily Limm has demonstrated that redwoods often receive up to 40% of the water they require through fog. This dependence on fog means that potential changes in the fog patterns of our region may very well effect the distribution of redwoods and populations of other plant communities – and such changes could have a significant impact on agriculture and overall environmental health.

Pepperwood’s Dr. Lisa Micheli explains that “fog is the most mysterious piece of current and future climate science.” Unlike other meteorological processes, there are no physical models capable of predicting fog formation to date. So while meteorologists forecast rain based on climatic factors like temperature and relative humidity, no such equivalent has been established for fog. “Basic empirical research is needed before we can even think about formulating accurate climate models to help us understand the role of fog in the Bay Area’s ecosystems,” says Dr. Micheli.

So what is it that makes fog so mysterious? There is a complex set of drivers that shape advective fog formation including ocean upwelling, wind speed and direction, and the differential in temperature between the ocean and the land. The challenge is determining how these factors interact with each other to create the poorly understood “flow” of fog from the sea to the land that we observe on an almost daily basis.

Pepperwood is participating in a landmark fog monitoring project with Alicia Torregrosa of the U.S. Geological Survey and other researchers from the Pacific Coastal Fog Team, a multidisciplinary group of scientists including oceanographers, meteorologists and climatologists supported by the Gordon and Betty Moore Foundation’s TBC3 to Pepperwood. The goal of the project is to map historical fog frequency distributions using archival satellite images and to develop field-based monitoring protocols that will complement these remote data sources moving forward.

Fog sensor near Pepperwood's Bechtel House
To aid in the collection of data, Pepperwood steward Dave Anderson helped install a state-of-the-art fog sensor on loan from Environment Canada for the summer of 2012 to measure visibility and liquid water content of localized fog. An identical sensor was placed at the Bodega Bay Marine Laboratory managed by UC Davis. Set 50Km apart and spanning from the coast to the Mayacamas mountains of Pepperwood, data from these sensors will help scientists better understand the process of fog as it forms over the Pacific Ocean and is pulled inland by lower pressure systems to the east.  

Get real time data from Pepperwood’s weather station.

Wednesday, September 19, 2012

Searching for Pepperwood's Reptiles and Amphibians

By Jay Scherf

Western Skink (Plestiodon skiltonianus)
Our laughter echoed up the hillside.  I mean, how often do clueless little animals bury themselves in your hair? The skink we’d caught, still young with an electric blue tail, had been brave enough to crawl out of my hand and up my shoulder. When my co-volunteer Jenny was able to fish it out of the burrow it’d made on the back of my head, it squirmed through her fingers, fell on my lap, and decided to nestle in my fly instead.

That’s what the herp survey’s about, though: looking for something to surprise us. Now, in the dry season when reptile and amphibian activity is low, Jenny and I find less animals hiding under our 18 plywood cover boards than in the spring. What does turn up, then, is often unexpected.

Western Fence Lizard (Sceloporus occidentalis) 
Like the racer we found last month at double ponds; a clever diurnal snake, it locked its gaze with mine like it knew what I was the moment I lifted it close to me. Or the nesting mouse near the observatory, huddling in its ball of moss. And the Ensatina salamander, a delicate little fingerling, hiding in an abandoned rodent burrow among the parched live oaks on Grouse Hill. Only the fence lizards skittering through the leaves, the dozens of tiny chorus frogs at the ponds, and the resident scorpion of Redwood Canyon #1 make our list without fail; whatever else we find is left to chance. 

But we always find something. That’s the thing about herps: they’re accessible, they’re easy to catch, and they make an impression on you quickly. Sure, bobcats and falcons are more impressive than bluebellys, but don’t expect to handle any soon. Herps, unlike the other vertebrates at Pepperwood, offer hands-on and intimate experience with sentient creatures of our hills. Hold scaly nature in your hand; see what this ecosystem’s made of. I can watch them breathe, feel their tongues flick me and their muscles weave, see them look me in the eye—no binoculars involved. Science gets real beyond the data sheets.

That’s the real story here, the most meaningful part of all this. Though as citizen scientists less is expected of us than in academia, the data we collect is solid, and looking at trends in our statistics tells us loads about our herps that can’t be learned by simply picking them up. That said, hard numbers lack feeling, and wouldn’t be relevant without the connections we make with animals in the field. If I’ve taken anything from the herp survey, it’s that the scientific process includes more than what’s on our clipboards. That the numbers are just a big, organized extension of the same curiosity I felt catching lizards as a kid.  Jay Scherf

Northwestern Gartersnake (Thamnophis ordinoides )
being held by blog post author Jay Scherf
Jay Scherf is a Pepperwood volunteer who worked on our "Herp Survey" this summer. This project records counts of reptile and amphibian species present at  specific locations throughout the preserve for the  purpose of monitoring  distribution and population  over time. Jay has written for North Bay Bohemian and is currently a student at UC Berkeley.