Noah Knowles

Noah Knowles

Research Hydrologist

National Research Program

Phone: 650-329-4476

345 Middlefield Road
Menlo Park, CA 94025


My work involves the application of climate science, numerical modeling, and analysis of large datasets to diverse natural systems. I work both alone and in multidisciplinary projects studying systems in which climate change in various manifestations could have an important influence. My work has included documenting hydrometeorological changes on a west-wide scale, hydrologic changes in California, and estuarine water-quality issues associated with climate change. Since 2006, I have been involved with a large, multidisciplinary project to assess the impacts of projected climate change on California's primary hydrological system, the San Francisco Estuary and its watershed.

I received a BS and MS in Physics from the University of Illinois, Urbana-Champaign in 1991 and 1993, respectively. I received a PhD in Oceanography from Scripps Institution of Oceanography (SIO) at the University of California, San Diego in 2000. I subsequently served as a postdoctoral researcher at SIO, then as a National Research Council Research Associate with the U.S. Geological Survey in Menlo Park, California. My research topics have included historical trends in precipitation form in the western U.S. and the influence of projected climate change in California, including changes in snowpack, runoff timing, and San Francisco Bay-Delta water quality. I am currently a Research Hydrologist with the USGS, and my research interests include analysis of regional and national hydrometorological trends and variability, continued hydrologic and estuarine model development, development of hydroclimate scenarios for use in evaluating ecological impacts, and changes in estuarine water quality and shoreline risks due to sea level rise.



Knowles, N. 2015. Trends in Snow Cover and Related Quantities at Weather Stations in the Conterminous United States. J. Climate28, 7518–7528. [Link]

Cloern J.E., Knowles N., Brown L.R., Cayan D.R., Dettinger M.D., Morgan T.L., Schoellhamer D.H., Stacey M., van der Wegen M., Wagner R.W., Jassby A.D. 2011. Projected evolution of California’s San Francisco Bay-Delta-River system in a century of climate change. PLoS ONE,6(9). [Link]

Brown, L.R., W.A. Bennett, R.W. Wagner, T. Morgan-King, N. Knowles, F. Feyrer, D. Schoellhamer, M. Stacey, M. Dettinger. 2011. Implications for Future Survival of Delta Smelt from Four Climate Change Scenarios for the Sacramento-San Joaquin Delta, California. Estuaries and Coasts36(4). [Link]

Knowles, N., 2010. Potential inundation due to rising sea levels in the San Francisco Bay region. San Francisco Estuary and Watershed Science,8(1). [Link]

Dettinger, M.D., H. Hidalgo, T. Das, Cayan, D.R., and Knowles, N., 2009. Projections of potential flood regime changes in California. California Climate Change Center publication CEC-500-2009-050-F, 68 pages. [Link]

Ganju, N.K., Knowles, N., and Schoellhamer, D.H., 2008. Temporal downscaling of decadal sediment load estimates to a daily interval for use in hindcast simulations. Journal of Hydrology 349(3-4): 512-523. [Link]

Knowles, N., Dettinger, M.D., and Cayan, D.R., 2006. Trends in snowfall versus rainfall in the western United States. Journal of Climate,19(18), 4545–4559. [Link]

Cloern, J. E., Schraga, T.S., Lopez, C.B., Knowles, N., Labiosa, R.G., and Dugdale, R., 2005. Climate anomalies generate an exceptional dinoflagellate bloom in San Francisco Bay. Geophysical Research Letters32, L14608. [Link]

Knowles, N. and Cayan, D.R., 2004. Elevational dependence of projected hydrologic changes in the San Francisco Estuary and watershed.Climatic Change62, 319-336. [Link]

Cayan, D.R., Dettinger, M.D., Redmond, K., McCabe, G., Knowles, N., and Peterson, D.H., 2003. "The transboundary setting of California's water and hydropower systems—linkages between the Sierra Nevada, Columbia, and Colorado hydroclimates", book chapter. [Link]

Dettinger, M.D., Bennett, W.A., Cayan, D.R., Florsheim, J., Hughes, M., Ingram, B.L., Jassby, A., Knowles, N., Malamud, F., Peterson, D.H., Redmond, K., and Smith, L., 2003. Climate science issues and needs of the CALFED Bay-Delta Program. American Meteorological Society, 83rd Annual Meeting, Impacts of Water Variability Symposium, Long Beach, California, 7.11-1 to 7.11-4. [Link]

Knowles, N., 2002. Natural and human influences on freshwater inflows and salinity in the San Francisco Estuary at monthly to interannual scales. Water Resources Research38, 25-1-25-11. [Link]

Knowles, N. and Cayan, D.R., 2002. Potential effects of global warming on the Sacramento/San Joaquin watershed and the San Francisco Estuary. Geophysical Research Letters29, 38-1-38-4. [Link]

Stahle, D., Therrell, M., Cleaveland, M.K., Cayan, D.R., Dettinger, M.D., and Knowles, N., 2001. Ancient blue oaks reveal human impact on San Francisco Bay salinity. EOS: Transactions, American Geophysical Union, 82(12). [Link]

Knowles, N. 2000. Modeling the hydroclimate of the San Francisco Bay-Delta Estuary and watershed. Doctoral Dissertation, Scripps Institution of Oceanography. La Jolla, California, University of California, San Diego. [Link]