Interannual variability of relative angular momentum in the Northern Hemisphere and its relationship with the North Atlantic oscillation and the Arctic oscillation

L. DE LA TORRE, L. GIMENO, P. RIBERA, D. GALLEGO, R. GARCÍA, E. HERNÁNDEZ

Abstract

The relative angular momentum (RAM) from 500 hPa to 200 hPa and from 55º N to 90 ºN was computed for the 1958-1998 period. NCAR-NCEP reanalysis data were used in this study, whose main purpose was to find an annual measurement to compare with the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO). Annual values of RAM exhibited a clear positive trend consistent with positive trends found in AO and NAO. The correlations between RAM and AO were higher than those between RAM and NAO and the spectral analysis showed a common significant band of oscillation ca. to eight years.

Keywords

Variability; angular momentum; North Atlantic and Artic oscillations

Full Text:

pdf