Now showing items 1-14 of 14

    • Attribution of Declining Western U.S. Snowpack to Human Effects 

      Pierce, David W.; Barnett, Tim P.; Hidalgo León, Hugo G.; Das, Tapash; Bonfils, Céline; Santer, Benjamin D.; Bala, Govindasamy; Dettinger, Michael D.; Cayan, Daniel R.; Mirin, Arthur A.; Wood, Andrew W.; Nozawa, Toru (2008-12-01)
      Observations show snowpack has declined across much of the western United States over the period 1950–99. This reduction has important social and economic implications, as water retained in the snowpack from winter storms ...
    • California Climate Change Center Report Series Number 2008-0XX 

      Miller, Norman L.; Duffy, P. B.; Cayan, Daniel R.; Hidalgo León, Hugo G.; Jin, J.; Kanamaru, H.; Kanamitsu, M.; O'Brien, T.; Schlegel, N. J.; Sloan, L. C.; Snyder, M. A.; Yoshimura, Kei (2008-06)
      Four dynamic regional climate models (RCMs) and one statistical downscaling approach were used to downscale 10 years of historical climate in California. To isolate possible limitations of the downscaling methods, we ...
    • Changes in Aridity in the Western United States 

      Hidalgo León, Hugo G.; Dettinger, Michael D.; Cayan, Daniel R. (2008-08)
      It is often remarked that most of the western US (Figure 1) is “always in drought,” especially by visitors from wetter climates. The plants and landforms of the West, however, are more or less adapted to the region’s ...
    • Climate change scenarios and sea level rise estimates for California 2008 Climate Change Scenarios Assessment 

      Cayan, Daniel R.; Tyree, Mary; Dettinger, Michael D.; Hidalgo León, Hugo G.; Das, Tapash; Maurer, Edwin P.; Bromirski, Peter; Graham, Nicholas A. J.; Flick, Reinhard (2009-03)
      For the 2008 California Climate Change Assessment, to further investigate possible future climate changes in California, a set of 12 climate change model simulations was selected and evaluated. From the Intergovernmental ...
    • Detection and Attribution of Streamflow Timing Changes to Climate Change in the Western United States 

      Hidalgo León, Hugo G.; Das, Tapash; Dettinger, Michael D.; Cayan, Daniel R.; Pierce, David W.; Barnett, Tim P.; Bala, Govindasamy; Mirin, Arthur A.; Wood, Andrew W.; Bonfils, Céline; Santer, Benjamin D.; Nozawa, Toru (2009-07)
      This article applies formal detection and attribution techniques to investigate the nature of observed shifts in the timing of streamflow in the western United States. Previous studies have shown that the snow hydrology ...
    • Detection and Attribution of Temperature Changes in the Mountainous Western United States 

      Bonfils, Céline; Pierce, David W.; Hidalgo León, Hugo G.; Bala, Govindasamy; Das, Tapash; Cayan, Daniel R.; Doutriaux, Charles; Wood, Andrew W.; Nozawa, Toru; Barnett, Tim P.; Santer, Benjamin D.; Mirin, Arthur A. (2008-04-22)
      Large changes in the hydrology of the western United States have been observed since the mid-twentieth century. These include a reduction in the amount of precipitation arriving as snow, a decline in snowpack at low and ...
    • Downscaling With Constructed Analogues: Daily Precipitation and Temperature Fields Over The United States 

      Hidalgo León, Hugo G.; Dettinger, Michael D.; Cayan, Daniel R. (2008-01)
      Daily precipitation and average temperature patterns for the contiguous United States were downscaled from a 2.5 x 2.5 degree (coarse) resolution grid to a 1/8 x 1/8 degree (fine) resolution grid using a constructed‐analogues ...
    • Human-Induced Changes in the Hydrology of the Western United States 

      Barnett, Tim P.; Pierce, David W.; Hidalgo León, Hugo G.; Bonfils, Céline; Santer, Benjamin D.; Das, Tapash; Bala, Govindasamy; Wood, Andrew W.; Nozawa, Toru; Mirin, Arthur A.; Cayan, Daniel R.; Dettinger, Michael D. (2008-02-22)
      Observations have shown that the hydrological cycle of the western United States changed significantly over the last half of the 20th century. We present a regional, multivariable climate change detection and attribution ...
    • Potential increase in floods in California’s Sierra Nevada under future climate projections 

      Das, Tapash; Dettinger, Michael D.; Cayan, Daniel R.; Hidalgo León, Hugo G. (2011-12)
      California’s mountainous topography, exposure to occasional heavily moisture-laden storm systems, and varied communities and infrastructures in low lying areas make it highly vulnerable to floods. An important question ...
    • Projections of Potential Flood Regime Changes in California 

      Dettinger, Michael D.; Hidalgo León, Hugo G.; Das, Tapash; Cayan, Daniel R.; Knowles, Noah (2009-03)
      Floods have been a recurring theme in California’s climatology, hydrology, and politics throughout its history. Today, California's aging water supply and flood protection infrastructures are challenged by major floods ...
    • Sources of Variability of Evapotranspiration in California 

      Hidalgo León, Hugo G.; Cayan, Daniel R.; Dettinger, Michael D. (2005-02)
      The variability (1990–2002) of potential evapotranspiration estimates (ETo) and related meteorological variables from a set of stations from the California Irrigation Management System (CIMIS) is studied. Data from the ...
    • Structure and Detectability of Trends in Hydrological Measures over the Western United States 

      Das, Tapash; Hidalgo León, Hugo G.; Dettinger, Michael D.; Cayan, Daniel R.; Pierce, David W.; Bonfils, Céline; Barnett, Tim P.; Bala, Govindasamy; Mirin, Arthur A. (2009-08)
      This study examines the geographic structure of observed trends in key hydrologically relevant variables across the western United States at ⅛° spatial resolution during the period 1950–99. Geographical regions, latitude ...
    • The utility of daily large-scale climate data in the assessment of climate change impacts on daily streamflow in California 

      Maurer, Edwin P.; Hidalgo León, Hugo G.; Das, Tapash; Dettinger, Michael D.; Cayan, Daniel R. (2010-06-30)
      Three statistical downscaling methods were applied to NCEP/NCAR reanalysis (used as a surrogate for the best possible general circulation model), and the downscaled meteorology was used to drive a hydrologic model over ...
    • Warming and Earlier Spring Increase Western U.S. Forest Wildfire Activity 

      Westerling, Anthony LeRoy; Hidalgo León, Hugo G.; Cayan, Daniel R.; Swetnam, Thomas W. (2006-08-18)
      Western United States forest wildfire activity is widely thought to have increased in recent decades, yet neither the extent of recent changes nor the degree to which climate may be driving regional changes in wildfire has ...