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Relationships between California rainfall variability and large‐scale climate drivers
Author(s) -
Fierro Alexandre O.
Publication year - 2014
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.4112
Subject(s) - climatology , pacific decadal oscillation , teleconnection , sea surface temperature , environmental science , el niño southern oscillation , la niña , north atlantic oscillation , geology
Bootstrapped correlation statistics of seasonally averaged monthly rainfall anomalies for the period 1950–2012 were evaluated between a comprehensive set of Atlantic‐ and Pacific‐based large‐scale climate drivers and a group of representative stations over the state of California, United States. In line with past seminal works, the analysis showed a dominant influence of the El Niño–Southern Oscillation (Pacific Decadal Oscillation) during the wetter (drier) period, particularly to the south (north) of the state. The largest correlation magnitudes were obtained for the Southern Oscillation Index (SOI) and the sea surface temperature (SST)‐based El Niño–Southern Oscillation (ENSO) indices Niños 3 and 3.4. A point‐by‐point correlation analysis with global SSTs, principal component analysis on the Pacific SST fields and wavelet spectral decomposition all assessed the robustness of the aforementioned relationships. The point‐by‐point correlation analysis with the SSTs further revealed an overall lack of relationships between rainfall and Atlantic‐based climate drivers and suggested that Indian Ocean SSTs are weakly correlated with California rainfall. This analysis also revealed that the relationship of northern California rainfall with the Pacific Decadal Oscillation (PDO) could be attributed to warm SST anomalies confined along the North American coast during the warm phase of the PDO. Notably, the wavelet analysis applied to extended rainfall records (1900–2012) revealed that the peaks in the rainfall power spectrum for southern California during the drier period are coincident with calendar years associated with the nearby passage or landfall of tropical systems in the southern California/North Baja region rather than teleconnections with large‐scale climate drivers.