Details:

Journal Title:
Journal of Climate
Personal Author:
Seager, Richard ; Henderson, Naomi
Seager, Richard ; Henderson, Naomi Less -
Corporate Authors:
United States. National Weather Service ; National Centers for Environmental Prediction (U.S.)
United States. National Weather Service ; National Centers for Environmental Prediction (U.S.) Less -
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office) ; NWS (National Weather Service) ; NCEP (National Centers for Environmental Prediction)
OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office) ; NWS (National Weather Service) ; NCEP (National Centers for Environmental Prediction) Less -
Description:
The causes of the high pressure ridge at the North American west coast during winter 2013/14, the driest winter of the recent California drought, are examined. The ridge was part of an atmosphere–ocean state that included anomalies, defined relative to a 1979–2014 mean, of circulation across the Northern Hemisphere, warm sea surface temperatures (SSTs) in the tropical western and northeastern Pacific and the south Indian Ocean, and cool SSTs in the central tropical Pacific. The SST anomalies differ sufficiently between datasets that, when used to force atmosphere models, the simulated circulation anomalies vary notably in realism. Recognizing uncertainty in the SST field, the authors use idealized tropical SST anomaly experiments to identify an optimal combination of SST anomalies that forces a circulation response that best matches observations. The optimal SST pattern resembles that observed but the associated circulation pattern is much weaker than observed, suggesting an important but limited role for ocean forcing. Analysis of the equilibrium and transient upper-troposphere vorticity balance indicates that the SST-forced component of the ridge arose as a summed effect of Rossby waves forced by SST anomalies across the tropical Indo-Pacific oceans and drives upper-troposphere convergence and subsidence at the west coast. The ridge, in observations and model, is associated with northward and southward diversion of storms. The results suggest that tropical Indo-Pacific ocean SSTs helped force the west coast ridge and drought of winter 2013/14.
Keywords:
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Climatic Changes Modeling Numerical Analysis Ocean-atmosphere Interaction Teleconnections Variability Climate Variability Interannual Variability Modeling
Source:
Journal of Climate, 29(22), 8027-8049.
DOI:
https://doi.org/10.1175/JCLI-D-16-0145.1
Document Type:
Journal Article
Funding:
Grant no. NA14OAR4310232
Place as Subject:
North America
Rights Information:
Other
Compliance:
Submitted
Main Document Checksum:
[+]
urn:sha256:ccf36b1cd3bd5ee3cfff68e3609dc08ab8f4d9add4f48d65c111bd66169f5b94
Download URL:
https://repository.library.noaa.gov/view/noaa/28348/noaa_28348_DS1.pdf
File Type:

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