While the East Coast ploughs through frozen weather, California is currently under a drought emergency.
To get a better understanding of what caused the extreme weather predicament, The Daily spoke with Daniel Swain—third year Ph.D. student in environmental earth system science studying atmospheric processes that impact global climate change—who coined the phrase “Ridiculously Resilient Ridge” to explain California’s dry spells.
The Stanford Daily (TSD): How severe is the current California drought?
Daniel Swain (DS): By most metrics it’s the worst drought that California has seen in its historical record—at least as far as humans have been taking records in the state. We know that the calendar year 2013 was the driest in at least 119 years and probably much longer than that.
The current water year between October and now is the driest to date…so if you use all of these different metrics about the amount of precipitation that California’s had to describe how sever the drought is, it’s certainly the worst in living memory and probably the worst in a significantly longer period than that.
TSD: What major factors, environmental or otherwise, have led to the current drought?
DS: From an atmospheric perspective, the proximate cause of the drought in California is this big ridge of high pressure over the north Pacific. You can sort of think of it as this big mass of warm air that’s essentially been sitting there more or less in the same place for many months now, and what this does is redirect the storm track away from California. Normally we’d see a number of Pacific storms during the winter time here in California but so far this winter, and for the second half of last winter as well, really all of these storms have gotten redirected…into British Columbia and Alaska.
TSD: What are state officials doing in response and do you think this is enough?
DS: As I’m sure you’re aware, the governor declared a drought emergency in California last week, and as far as I understand it opens up some legal pathways and it allows for…enforcing certain kinds of regulations in terms of water use in California.
The tricky part with a situation like this is how water is managed in California. Most likely the agricultural interests in California will be the ones most immediately affected by water restrictions and water shortages, but the current situation is acute enough that it will probably go beyond that and affect urban water users and day-to-day water use by your average person in California.
So I think what the state is doing right now is they’re gearing up for major conservation efforts. I know there was a recommendation for voluntary 20 percent reduction in water use across the board, but if this current situation continues the reduction of water use in California is going to have to be quite a bit higher than that. I know that certain local water districts are considering water rationing to the order of 50 percent reduction or more and those would be mandatory. So I think that the state is starting to sort of mobilize for big water restrictions in the next couple of months.
TSD: What immediate impact, if any, does the drought have on the Stanford community and what can the Stanford community do in response?
DS: Much of the Bay Area including the Stanford area gets its water from largely non-local sources. The water actually comes from snowmelt in the Sierra Nevada mountain [range] that essentially flows over in the aqueduct to the Bay Area.
So we’re affected by the drought in the sense that really all of Northern California has too little water right now. We’re in slightly better shape than some smaller communities who are relying on local sources because we have a little bit of a buffer from precipitation from previous years in the reservoirs, but eventually if this keeps up there will probably be some form of water restrictions here.
I think for now, obviously, a good thing to do for everyone is to be conscious of water use and maybe take some active efforts to reduce your water use. Sometimes that can be as simple as not watering your lawn or taking shorter showers or not washing your car. Doing those sorts of things now will help to lower potential for more serious water restrictions in the future. The current severity of the drought suggests that some of these smaller measures may not be enough even if everyone partakes so that’s all the more reason to conserve water now.
TSD: What is the outlook to when this drought will pass?
DS: The weather forecast for the next week or so is not very promising—pretty much all of the same for the next seven to 10 days. Certainly dry and certainly warm. Pretty much the outcome of the drought this year will be dependent on how much rain we get in February and March, and right now it doesn’t look particularly likely that February and March are going to be wetter than normal, which is what we would need to avoid some of this water rationing.
Unfortunately it looks like the chances of February and March being close to normal or drier than normal are quite high.
This interview has been edited and condensed.
Contact Ileana Najarro at inajarro ‘at’ stanford ‘dot’ edu.