Estuaries and Coasts

, Volume 34, Issue 3, pp 544-556

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Statistical Models of Temperature in the Sacramento–San Joaquin Delta Under Climate-Change Scenarios and Ecological Implications

  • R. Wayne WagnerAffiliated withDepartment of Civil and Environmental Engineering, University of California, Berkeley Email author 
  • , Mark StaceyAffiliated withDepartment of Civil and Environmental Engineering, University of California, Berkeley
  • , Larry R. BrownAffiliated withU.S. Geological Survey
  • , Michael DettingerAffiliated withU.S. Geological Survey, UC San Diego


Changes in water temperatures caused by climate change in California’s Sacramento–San Joaquin Delta will affect the ecosystem through physiological rates of fishes and invertebrates. This study presents statistical models that can be used to forecast water temperature within the Delta as a response to atmospheric conditions. The daily average model performed well (R 2 values greater than 0.93 during verification periods) for all stations within the Delta and San Francisco Bay provided there was at least 1 year of calibration data. To provide long-term projections of Delta water temperature, we forced the model with downscaled data from climate scenarios. Based on these projections, the ecological implications for the delta smelt, a key species, were assessed based on temperature thresholds. The model forecasts increases in the number of days above temperatures causing high mortality (especially along the Sacramento River) and a shift in thermal conditions for spawning to earlier in the year.


Climate change Temperature model Delta smelt