Influence of cold air pooling on persistence of snowpack at a finer scale.

<p>Comparison of June snow pack conditions shown for the headwaters of the Tuolumne River estimated using the worst case (GFDL-A2) future climate projection. Snowpack was simulated a) without an adjustment for cold-air pooling (CAP) and b) with a temperature correction factor (−1.6°C) to adjust air temperatures and simulate cold-air pooling (CAP). Panel c) shows the difference in the spatial extent and depth of SWE achieved by incorporating CAP into the future climate projection.</p

Historic changes in April 1^st snow water equivalents.

<p>A spatially distributed estimate of the change in April 1^st snow water equivalent (SWE) from historic (1951–1980) to current (1981–2010) climatic conditions.</p

Latitude effects on goodness-of-fit parameters for modeled snow water equivalents during the calibration period from 1998 to 2009.

<p>Latitude effects on goodness-of-fit parameters for modeled snow water equivalents during the calibration period from 1998 to 2009.</p

Visual comparison between modeled snow covered area and permanent snowpack locations.

<p>Comparison of snow covered area (SCA) simulated using the Basin Characterization Model (BCM) for September 2009 and areas of persistent snowpack for Mount Shasta, located in the northern study region, and along the southern Sierra Nevada crestline within the headwaters of the San Joaquin and Kings River watersheds.</p

Influence of cold-air pooling on simulations of regional snow water equivalents.

<p>Monthly snow water equivalent (SWE) spatially averaged over the entire Sierra Nevada Ecoregion for the early-century period (2011–2040) using GFDL-A2, showing increases in SWE related to the use of a temperature correction factor (−1.6°C) to adjust minimum air temperatures and simulate cold-air pooling (CAP).</p

Simulated April 1^st snowpack under current and late-century climates for four National Park units.

<p>Detail of four National Park units in the Sierra Nevada Ecoregion showing April 1^st snow water equivalent (SWE) for current (1981–2010) and late 21^st century (2071–2100) climatic conditions. Late-century scenarios represent “business as usual” carbon emissions for warmer-wetter (PCM-A2) and warmer-drier future climates (GFDL-A2).</p

Visual comparison between modeled snow covered area and satellite imagery.

<p>Comparison of snow water equivalent (SWE) simulated with the Basin Characterization Model (BCM) and MODIS snow covered area (SCA) for February 2001 and May 2002.</p

Changes in April 1^st snowpack under various climatic conditions in four National Park units.

<p>Simulated April 1^st snow water equivalent (SWE) spatially averaged across the boundaries of four National Park units for historic (1951–1980), current (1981–2010), and future (2011 to 2100) climatic conditions. The data, organized from left to right, show a worst case scenario (GFDL-A2), two moderate case scenarios (GFDL-B1 and PCM-A2) and a best case scenario (PCM-B1).</p

Percent change in April 1st snow water equivalent from current climatic conditions (1981–2010) to early, mid and late 21st century climatic projections simulated for four National Park units located within the Sierra Nevada Ecoregion.

<p>Percent change in April 1st snow water equivalent from current climatic conditions (1981–2010) to early, mid and late 21st century climatic projections simulated for four National Park units located within the Sierra Nevada Ecoregion.</p

Comparison of mean minimum air temperatures from 1896 to 2009 for snow courses with and without the potential to produce cold-air pooling (CAP).

<p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0106984#pone-0106984-g001" target="_blank">Figure 1</a> for station locations.</p><p>Comparison of mean minimum air temperatures from 1896 to 2009 for snow courses with and without the potential to produce cold-air pooling (CAP).</p