Impacts of low frequency variability modes on Canadian winter temperature

Bonsal, Barrie; Shabbar, Amir; Higuchi, Kaz

doi:10.1002/joc.590

Cited by 125 publications

(137 citation statements)

References 24 publications

Supporting

Mentioning

127

Contrasting

Order By: Relevance

“…The correlations between surface temperature and circulation pattern described by EOF 2 of the station series (Figure 4(b)) show more seasonal differences (Figure 7(e)-(h)). The correlation pattern in winter reflects the western domain of the typical winter NAO/AO and temperature quadrupole correlation pattern (Hurrell, 1995;Thompson and Wallace, 1998;Stephenson et al, 2000;Bonsal et al, 2001;Slonosky and Yiou, 2001) with negative correlations over northeastern Canada and Greenland, and positive correlations over southeastern Canada and the northeastern USA (see also Figure 7(m), which is very similar to Figure 7(e)). Again, these correlations can be explained by the advection of cold polar air over the northern regions when the north-south pressure gradient over the North Atlantic is greater than normal (a strong Icelandic low leading to cyclonic circulation over the northern North Atlantic) and vice versa.…”

Section: Circulation Links With Temperature and Implications For Climsupporting

confidence: 70%

“…The configuration of pressure anomalies depicted by EOF 1 of the station data analysis is associated with cold air outbreaks from the Arctic spreading over central and eastern Canada (see Section 6 also; Bonsal et al, 2001). This pattern is somewhat similar, although displaced to the east, to the western North American centre of action of the Pacific-North American (PNA) pattern described by Wallace and Gutzler (1981), a teleconnection pattern based on a rotated EOF analysis of hemispheric-scale gridded pressure data.…”

Section: Station-based Eofsmentioning

confidence: 99%

See 1 more Smart Citation

Canadian pressure observations and circulation variability: links to air temperature

Slonosky

Graham

2005

Int. J. Climatol.

View full text Add to dashboard Cite

A set of 71 station series of surface pressure from Canada and Greenland have been examined for quality control and homogeneity. These records range in length from 50 to 130 years. The object of this exercise was to investigate stationbased surface pressure series and atmospheric circulation on a decadal time scale, and to examine the effects of the atmospheric circulation on climate. The data considered here are monthly means.Several major inhomogeneities were discovered during the course of this exercise, the most serious of which relates to a Canadian-wide change in reporting practice which took place in 1977. This type of inhomogeneity is almost impossible to uncover using conventional homogenization techniques based upon reference series. The final homogenized series show appreciable differences in regional trends of atmospheric pressure compared with the unhomogenized series, particularly in southern Canada.Empirical orthogonal function (EOF) analyses on the station series revealed three main modes of circulation over Canada and Greenland; these patterns were compared with results from the UK Hadley Centre's gridded pressure dataset. There are appreciable differences between the leading EOF modes of the two datasets, which may be due to an artificially enhanced number of degrees of freedom in the gridded dataset. Trends in atmospheric pressure were also calculated; these suggest an intensification of zonal flow during winter over the period 1950-98, but these variations appear to be much less pronounced and not statistically significant when considered over the whole of the 20th century.The new station database was also compared with a gridded surface temperature dataset. There are strong correlations between the various circulation indices and temperature anomalies. Some of the trends of temperature in Canada during the period 1950-98 can be attributed to these changes of atmospheric circulation. The regional atmospheric circulation indices described here are shown to have considerable influence on the surface temperature variability and trends for all seasons of the year.

show abstract

Section: Circulation Links With Temperature and Implications For Climsupporting

confidence: 70%

Section: Station-based Eofsmentioning

confidence: 99%

Canadian pressure observations and circulation variability: links to air temperature

Slonosky

Graham

2005

Int. J. Climatol.

View full text Add to dashboard Cite

show abstract

“…Papineau (2001) Mantua and Hare (2002). Bonsal et al (2001) and Shabbar and Bonsal (2004) examined PDO impacts on winter ( JFM) temperature variability over Canada. ENSO and PDO mainly affect western and central Canada, and ENSO modulation is also reported.…”

Section: Temperaturementioning

confidence: 99%

Pacific Decadal Oscillation and the Hydroclimatology of Western Canada—Review and Prospects

Whitfield¹,

Moore²,

Fleming³

et al. 2010

Canadian Water Resources Journal

114

127

View full text Add to dashboard Cite

Abstract:The Pacific Decadal Oscillation (PDO) is a large-scale climate system feature that influences the surface climate and hydrology of western North America. In this paper, we review the literature describing the PDO and demonstrate its effects on temperature, precipitation, snowfall, glacier mass balance, and streamflow with a focus on western Canada, and particularly British Columbia. We review how the PDO index was developed and discuss other North Pacific climate patterns that resemble the PDO. The impacts of PDO on glacier mass balance and streamflow from retrospective studies are also reviewed and illustrated with specific examples from BC. We assess the current state of knowledge regarding the PDO and provide a critical assessment of its use in hydroclimatology. This information should provide insight on the sensitivity of projects to climatic variability.

show abstract

“…One way to investigate the interactions between the PDO-and ENSO-related responses is to stratify the streamflow into climate categories defined by a combination of the ENSO and PDO states (e.g. Bonsal et al, 2001). Following this approach, we defined eight climate categories, namely, warm PDO, cool PDO, El Nino, La Nina, El Nino/warm PDO, La Nina/warm PDO, El Nino/cool PDO and La Nina/cool PDO.…”

Section: Interdecadal Streamflow Variabilitymentioning

confidence: 99%

“…More recently, Brown and Comrie (2004) have shown inconsistencies in the canonical ENSO response in western US precipitation commensurate with the PDO phase shift. The PDO regime has also been shown to modulate winter temperature responses over most of western Canada during El Nino and La Nina events (Bonsal et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Low-frequency variability in Southwestern Canadian stream flow: links with large-scale climate anomalies

Gobena

Gan

2006

Int. J. Climatol.

View full text Add to dashboard Cite

By applying a suit of statistical techniques, this study investigated the impacts of the El Nino-Southern Oscillation (ENSO), the Pacific-North America (PNA) pattern, the West Pacific (WP) pattern and the Pacific decadal oscillation (PDO) teleconnections on the interannual to interdecadal variability of southwestern (SW) Canadian streamflow anomalies. It is shown that El Nino (La Nina) episodes lead to significant negative (positive) streamflow anomalies in several subregions during the spring and/or summer months following the ENSO onset year. A simple composite analysis of streamflow for anomalous PNA years conditioned on non-ENSO years showed that the high phase of PNA could also produce an El Nino-like streamflow response over the region. In addition, the ENSO-streamflow relationship appears to be modulated by the interdecadal oscillation of the North Pacific (NP) climate as indexed by the PDO. The interaction between PDO and ENSO was found to be constructive when the two are in phase and destructive otherwise. The potential of using the three large-scale climate anomalies (ENSO, PNA and PDO) for long-range streamflow forecasting in SW Canada was assessed using a partial correlation analysis with the southern oscillation index (SOI), the PNA and PDO indices at lead times of up to 10 months. While partial correlations with all three indices were found to be statistically significant for several basins, the ENSO and PDO effects appear to be far more important than that of the PNA pattern. The winter season SOI, which is an indicator of the mature phase of ENSO, shows modest correlations with basins whose flow regimes are dominated by winter rain/spring snowmelt. On the other hand, the winter season PDO shows relatively strong correlations with basins originating in the Rocky Mountains, whose flow regimes are dominated by spring-summer snow/glacier melt. The modest SOI-streamflow relationships are partly attributed to nonlinearity induced by the interference from the extratropical sources of variability (i.e. PNA and PDO). Long-range streamflow forecasting strategies for this region should thus incorporate information from the three large-scale climate anomalies.

show abstract

Impacts of low frequency variability modes on Canadian winter temperature

Cited by 125 publications

References 24 publications

Canadian pressure observations and circulation variability: links to air temperature

Canadian pressure observations and circulation variability: links to air temperature

Pacific Decadal Oscillation and the Hydroclimatology of Western Canada—Review and Prospects

Low-frequency variability in Southwestern Canadian stream flow: links with large-scale climate anomalies

Contact Info

Product

Resources

About