Mechanisms for Snow Cover Variations over the Sierra Nevada: 2001-2012
Menglin S. Jin Marshall Shepherd, Andy Chiuppi III
ABSTRACT
This study, from high-resolution satellite observations, reanalysis and ground observations,
identifies various remote, regional, and local mechanisms responsible for the snowcover variations during 2001-2012 with a focus on the two La Niina winters
of 2008 and 2011, respectively. Complex physical, mechanical, and ecological
processes, at multiple temporal and spatial scales, contribute to snowpack change in the Sierra Nevada Mountain Range (SNMR).
On one hand, large-scale dynamic events, such as El Nina and La Nina displace the polar jet stream to affect precipitation over the
remote region SNMR via teleconnection. On the other hand,
regional biosphere-land-atmosphere interactions and local land cover change also affect boundary-layer water vapor,
surface temperature, as well as snowfall and snow accumulation. Specifically, regional forest water recycle,
mountain-parallel low-level jet stream, and snow-albedo feedback processes are responsible,
at least partly, to snow accumulation on SNMR, while the large-scale remote climate patterns
over the Pacific Ocean control the polar jet stream position and consequently affect the precipitation of SNMR.