The Spring Runoff Pulse from the Sierra Nevada
D. Cayan (1,2), D. Peterson (2), L. Riddle (1), M. Dettinger (2), and R. Smith (2)
(1)Scripps Institution of Oceanography
(2)USGS
Summary of another Web site
Most years, one pulse of snowmelt marks the change from winter to spring.
- The spring pulse occurs later during La Niña years, while no delay occurs during El Niño years.
- The spring pulse comes earlier in years with light snowpack, and comes later in years with heavy snowpack. Two possible causes are:
- Long winters, associated with heavy snowpacks; and
- Extended warm weather needed to start melting the heavy snowpack.
- The spring weather that triggers the pulse features a strong western high pressure ridge. This weather produces widespread warming, presumably because of strong solar heating of the snowpack.
For further information, contact: Daniel Cayan
USGS El Niño Home Page
URL: http://walrus.wr.usgs.gov/elnino/merced.html
Maintained by: Laura Zink Torresan
Last modified: 8 August 2002 (lzt)
For more information, please contact the El Niño Web Team