scholarly journals Influence of the Pacific Decadal Oscillation on the climate of the Sierra Nevada, California and Nevada

2003 ◽  
Vol 59 (2) ◽  
pp. 151-159 ◽  
Author(s):  
Larry Benson ◽  
Braddock Linsley ◽  
Joe Smoot ◽  
Scott Mensing ◽  
Steve Lund ◽  
...  

AbstractMono Lake sediments have recorded five major oscillations in the hydrologic balance between A.D. 1700 and 1941. These oscillations can be correlated with tree-ring-based oscillations in Sierra Nevada snowpack. Comparison of a tree-ring-based reconstruction of the Pacific Decadal Oscillation (PDO) index (D’Arrigo et al., 2001) with a coral-based reconstruction of Subtropical South Pacific sea-surface temperature (Linsley et al., 2000) indicates a high degree of correlation between the two records during the past 300 yr. This suggests that the PDO has been a pan-Pacific phenomena for at least the past few hundred years. Major oscillations in the hydrologic balance of the Sierra Nevada correspond to changes in the sign of the PDO with extreme droughts occurring during PDO maxima. Four droughts centered on A.D. 1710, 1770, 1850, and 1930 indicate PDO-related drought reoccurrence intervals ranging from 60 to 80 yr.

2012 ◽  
Vol 27 (4) ◽  
Author(s):  
Sze Ling Ho ◽  
Gesine Mollenhauer ◽  
Frank Lamy ◽  
Alfredo Martínez-Garcia ◽  
Mahyar Mohtadi ◽  
...  

2005 ◽  
Vol 18 (21) ◽  
pp. 4355-4373 ◽  
Author(s):  
Niklas Schneider ◽  
Bruce D. Cornuelle

Abstract The Pacific decadal oscillation (PDO), defined as the leading empirical orthogonal function of North Pacific sea surface temperature anomalies, is a widely used index for decadal variability. It is shown that the PDO can be recovered from a reconstruction of North Pacific sea surface temperature anomalies based on a first-order autoregressive model and forcing by variability of the Aleutian low, El Niño–Southern Oscillation (ENSO), and oceanic zonal advection anomalies in the Kuroshio–Oyashio Extension. The latter results from oceanic Rossby waves that are forced by North Pacific Ekman pumping. The SST response patterns to these processes are not orthogonal, and they determine the spatial characteristics of the PDO. The importance of the different forcing processes is frequency dependent. At interannual time scales, forcing from ENSO and the Aleutian low determines the response in equal parts. At decadal time scales, zonal advection in the Kuroshio–Oyashio Extension, ENSO, and anomalies of the Aleutian low each account for similar amounts of the PDO variance. These results support the hypothesis that the PDO is not a dynamical mode, but arises from the superposition of sea surface temperature fluctuations with different dynamical origins.


2009 ◽  
Vol 22 (7) ◽  
pp. 1819-1833 ◽  
Author(s):  
Courtenay Strong ◽  
Gudrun Magnusdottir

Abstract The leading pattern of extratropical Pacific sea surface temperature variability [the Pacific decadal oscillation (PDO)] is shown to depend on observed variability in the spatiotemporal distribution of tropospheric Rossby wave breaking (RWB), where RWB is the irreversible overturning of potential vorticity on isentropic surfaces. Composite analyses based on hundreds of RWB cases show that anticyclonic (cyclonic) RWB is associated with a warm, moist (cool, dry) column that extends down to a surface anticyclonic (cyclonic) circulation, and that the moisture and temperature advection associated with the surface circulation patterns force turbulent heat flux anomalies that project onto the spatial pattern of the PDO. The RWB patterns that are relevant to the PDO are closely tied to El Niño–Southern Oscillation, the Pacific–North American pattern, and the northern annular mode. These results explain the free troposphere-to-surface segment of the atmospheric bridge concept wherein El Niño anomalies emerge in summer and modify circulation patterns that act over several months to force sea surface temperature anomalies in the extratropical Pacific during late winter or early spring. Leading patterns of RWB account for a significant fraction of PDO interannual variability for any month of the year. A multilinear model is developed in which the January mean PDO index for 1958–2006 is regressed upon the leading principal components of cyclonic and anticyclonic RWB from the immediately preceding winter and summer months (four indexes in all), accounting for more than two-thirds of the variance.


2020 ◽  
pp. 1-41
Author(s):  
Xiaogu Zheng ◽  
Carsten S. Frederiksen

AbstractDecadal mean variables are frequently used to characterise decadal climate variabilities. Decadal means are often calculated using yearly data which can represent variability at time scales from annual to centennial. Residuals from interannual fluctuations may contribute to the variability in decadal time series. Such variability is more difficult to be predicted at the long range. Removing it from the decadal variability means that the remaining variability is more likely to arise from slowly varying multi-decadal or longer time scale external forcing and internal climate dynamics which are more likely to be predicted.Here, a new approach is proposed to understand the uncertainty, potential predictability and drivers of decadal mean variables. The covariance matrix of multivariate decadal running means is decomposed into unpredictable fast decadal variability and the potentially predictable slow decadal variability. EOF analysis is then applied to the decomposed matrices to find the dominant modes which may be related to the drivers of the two types of variabilities in the multivariate decadal means.The methodology has been applied to 140 year datasets of North Pacific sea surface temperature and the Northern Hemisphere 1000hPa geopotential height. For sea surface temperature, the Pacific Decadal Oscillation is the major driver of the fast decadal variability, while the radiative forcing and the Atlantic Multi-decadal Oscillation are major drivers of the slow decadal variability. For the 1000hPa geopotential height, fast decadal variability is associated with the Northern Annular Mode, the East Atlantic Mode and the Pacific Decadal Oscillation. Slow decadal variability is associated with the Northern Annular Mode and the Atlantic Multi-decadal Oscillation.


2021 ◽  
Vol 14 (4) ◽  
pp. 1861-1879
Author(s):  
Pedro Fernandes de Souza Neto ◽  
Djane Fonseca Da Silva ◽  
Henrique Ravi Rocha de Carvalho Almeida

The sea surface temperature is one of the main variables for analyzing the global climate, and with that, it is essential to know its behavior. Thus, the objective of this study is to understand the best temperature variability of the sea surface of the Atlantic and Pacific oceans, through information on the causes of its variability using Wavelet analysis, and also using the climatic trends of the TSM of the oceans. Sea surface temperature anomaly data obtained through the National Oceanic and Atmospheric Administration with period of 1955-2018, for the Atlantic and Pacific Oceans, divided into sectors and some statistical analyzes were used. Using the wavelet analysis method, it was possible to observe the phenomena El Niño South Oscillation, Atlantic Dipole, sunspots and Pacific Decadal Oscillation, acting on the studied time series; however, the Pacific Decadal Oscillation, which occurs in the Pacific Ocean, proved to be a phenomenon of dominant time scale in the Atlantic and Pacific Oceans. The Mann-Kendall trend test showed a linear increase in the sea surface temperature anomaly for the two studied Oceans, and in both, the South sector has a greater increase than the North sector. Climate trends indicate that the Pacific Ocean is warming more than the Atlantic Ocean. It is also possible to conclude that the Southern sector of the two Oceans is heating up more than the Northern sector. The signs of the limit ranges for the averages of the southern sectors demonstrate greater variability of the anomalies at the South Atlantic and South Pacific. The Northern sector was more similar to the general basin, both in the Atlantic and the Pacific, proving the importance of continental areas for warming the oceans. These results were strengthened with those found by box plots and frequency distribution. The warming of the Pacific was also reinforced in all statistics mad.


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