Relationship Between Atmospheric circulation and Snowpack in theWestern United States
Snow anomalies in the western United States (U.S.) have beenwidely investigated by many researchers due to its impact on wateravailability. This study focuses on how anomalous atmospheric circulationaffects snowpack accumulation in the western U.S. using observations andoutput from the National Center for Atmospheric Research (NCAR) CommunityClimate Model version 3 (CCM3). Our results indicate that themid-latitude atmospheric circulation anomalies induced by the ElNino-Southern Oscillation (ENSO) tend to drive winter precipitationshifts, leading to an anomalous snowpack distribution in the western U.S.The warm phase of ENSO produces increased snowpack in the Southwest,while the cold phase of ENSO generates increased snowpack in theNorthwest. Temperature has a secondary impact on the anomalous snowpackdistribution during ENSO episodes. Additionally, the non-linearatmospheric dynamics-related Pacific-North American (PNA) pattern isfound to strongly affect snow anomalies in the western U.S. independentfrom ENSO. The positive phase of the PNA pattern produces coldertemperature and stronger precipitation due to the lower pressure in theregion, leading to an above normal snowpack. Conversely, the negativephase of the PNA pattern generates warmer temperature and weakerprecipitation resulting from the higher pressure, producing a below thannormal snowpack in the western U.S. In general, the NCAR-CCM3 reproducesthe observed processes. However, model biases are identified andreported. The information provided in this study strengthens ourunderstanding of climate and water supply variability in the westernU.S.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Laboratory Directed Research andDevelopment
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 929077
- Report Number(s):
- LBNL-55404; HYPRE3; R&D Project: 366160; BnR: YN0100000; TRN: US200812%%594
- Journal Information:
- Hydrological Processes, Vol. 20, Issue 4; Related Information: Journal Publication Date: 02/27/2006; ISSN 0885-6087
- Country of Publication:
- United States
- Language:
- English
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