Snow Lab

Snow Lab

Robert Rhew

How does this winter’s snowfall compare to last year, or the last decade, or even the last century? While early November 2020 brought higher than normal snowfall to Donner Summit, the cumulative amount of winter snow as of January 3, 2021, is below the 40-year median. Putting any year in context like this relies on long-term snow measurements. For Donner Pass, these measurements are taken at the Central Sierra Snow Lab in Soda Springs, a University of California Berkeley research facility located about 10 miles due west of Truckee and 20 miles northwest of Lake Tahoe. Measuring snowpack is critically important to life in California and Nevada, and one of the oldest and most important stations doing this research in the Sierra Nevada is about to enter a new phase of operations.

The Central Sierra Snow Lab (aka “Snow Lab” or “CSSL”) is one of the nation's principal observatories of hydrological and meteorological phenomena in a mountain environment. The Snow Lab was originally established in 1946 by the US Army Corps of Engineers and Weather Bureau as one of three outdoor laboratories to study snow and snowmelt, with the purpose of solving hydrologic problems in the western United States. While the other two laboratories closed in the early 1950s, the Snow Lab survived and was managed by the U.S. Forest Service from 1954 to 1995. On its 50th anniversary in 1996, the USDA disbanded the project, and the 7 full-time employees either retired or were reassigned. The long-term investment in snow science was about to come to an end, with a potentially devastating loss of continuous snow data collection in a region of the Sierra Nevada with an extraordinarily long snow record. Combined with Donner Summit measurements collected by the Southern Pacific railroad, the snow record goes back to 1879.

Faced with this impending crisis, the Vice-Chancellor of Research at UC Berkeley agreed in 1996 to assume management of the Snow Lab through an agreement with the USDA Forest Service. The number of personnel decreased from seven to one. A talented young snow researcher named Randall Osterhuber was the sole USDA employee that transferred over to become the first UC Berkeley Central Sierra Snow Lab station manager. Like an Indiana Jones of snow, Randall has endured extreme weather conditions and outdoor adventures while collecting precise measurements, year after year, from 1996 all the way until his retirement last winter.

The major function of the Snow Lab is hydrological research and the station features a heavily-instrumented field site. Randall maintained the site and provided technical expertise to researchers from various research entities, such as the University of California, Department of Water Resources, National Weather Service, Natural Resource Conservation Service, Western Regional Climate Center, and USDA Forest Service. Over the years, the research projects at Snow Lab included a wide range of snow research: assessing the role of black carbon on snow; determining the isotopic evolution of the snowpack; developing new technologies to measure snowpack snow water equivalent; evaluating the operational utility of weather forecasts; using LiDAR to measure snowpack spatial and temporal distribution; determining trends in Sierra Nevada climatology and snowpack during the past six decades; modeling ground and surface water response to snow accumulation and ablation; modeling air temperature lapse rate; developing fluidless precipitation gauges; conducting snow surveys; improving avalanche safety and forecasting.

In the Donner-Tahoe community, the Snow Lab may be best known for the annual snow report it produces. This graph shows how each year compares with the long term historical record for snowfall. Snowfall is the most visible indicator of climate, and one of the most closely watched by snow sports enthusiasts. Even more important for water resources is the measure of the amount of water it contains, a quantity known as the Snow Water Equivalent (SWE). The Natural Resources Conservation Service (NRCS) maintains a long-term SWE instrument at the Snow Lab with records going back to 1980. With such a long dataset of multiple meteorological observations, we can have a much better understanding of climate change in the Sierra Nevada, such as what the overall rainfall patterns are, the changes to nighttime temperature, how many rain on snow events there are, and how fast the snow melts in the spring.

The 2019-20 winter brought a dual crisis to the Snow Lab. First, Randall retired in December 2019, bringing the station personnel count to zero. Second, the funding to the Snow Lab, which had been declining in real dollars for a decade, was under threat of being zeroed out. The Research Office which saved the Snow Lab 23 years earlier was working through multi-year budget austerity measures. Priority was being put into research centers that supported university research, whereas the Snow Lab served primarily to support government agencies and the local communities in the Central Sierra. The fact that UC Berkeley even runs a Snow Lab in Soda Springs is probably equally surprising to readers here as it is to members of the UC Berkeley community.

As the Faculty Director of the Central Sierra Field Stations (which includes the Snow Lab as well as the Sagehen Creek Field Station), I needed to figure out a path forward. In January 2020, I organized a meeting to bring together the many stakeholders interested in the future of the Snow Lab. People came from the Department for Water Resources, the National Weather Service, the NRCS/ USDA, UC Davis, the University of Nevada at Reno, the Desert Research Institute, a hydrology consulting firm, and the South Yuba River Citizens League. Each group extolled the importance of continuing Snow Lab operations, which ultimately convinced the university to allow a new station manager to be recruited.

COVID-19 stopped those plans. At the university, the pandemic led to closures of offices and laboratories, crippled the university budget, and led to a universal hiring freeze. After months of appeals to get an exceptional approval to replace the snow lab manager, a new manager is finally projected to start leadership at the Snow Lab within a few months. In the interim, a local hero, Justin Lichter, took up the role of collecting manual snow measurements at the Snow Lab to stem the loss of data that has been occurring since last December. With his support, we have been able to minimize the damage done to our long-term climatological records.

Thus the Snow Lab is about to write a new chapter of field measurements, one that will continue its record of science for the public good.

Robert Rhew is an earth system science professor in the Department of Geography at UC Berkeley. He serves as the Faculty Director for the UC Berkeley Central Sierra Field Stations. You can reach him at rrhew@berkeley.edu

Snowpack Chart 1879-2019