Independent Variables (Grids)

Time (time)	grid: /T (julian_day) ordered (1 Jan 1950) to (31 Aug 2017) by 1.0 N= 24715 pts :grid
longitude (longitude)	grid: /X (degree_east) periodic (0) to (2.5W) by 2.5 N= 144 pts :grid
latitude (latitude)	grid: /Y (degree_north) ordered (20N) to (90N) by 2.5 N= 29 pts :grid

Other Info

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The loading patterns of NAO and PNA are obtained using a rotated EOF (REOF) analysis following Barnston and Livezey (1987). The REOF is conducted for the monthly mean 500-hPa geopotential height anomalies over the Northern Hemisphere (20-90N) using the NCEP/NCAR reanalyses from 1951 to 2010. Monthly mean anomalies for all 12 calendar months and 10 rotated varimax spatial patterns are used. Since the NAO and PNA variability has the largest variance in the cold season, the patterns are thus dominated by characteristics in winter. Similar definition was used in Johansson (2007), Lin et al. (2009), and Frederiksen and Lin (2013). Analysis provided courtesy of Hai Lin (hai.lin@canada.ca) of Environment Canada.

References

Barnston, A. G., and R. E. Livezey, 1987: Classification, seasonality and persistence of low-frequency atmospheric circulation patterns. Mon. Wea. Rev., 115, 1083-1126.

Frederiksen, J., and H. Lin, 2013: Tropical-extratropical interactions of intraseasonal oscillations, J. Atmos. Sci., 70, 3180-3197.

Johansson, A, 2007: Prediction skill of the NAO and PNA from daily to seasonal time scales. J. Climate, 20, 1957-1975.

Lin, H., G. Brunet, and J. Derome, 2009, An observed connection between the North Atlantic Oscillation and the Madden-Julian Oscillation. J. Climate, 22, 364-380.

Last updated: Mon, 22 Jan 2018 15:49:47 GMT