Utilización del momento angular relativo para el estudio de NAO/AO

Abstract

North Atlantic extratropical variability is highly dominated by a variability mode called North Atlantic Oscillation --NAO-- or Arctic Oscillation --AO--. The difference in the nomenclature is due to the different points of view from which this variability mode is analysed: regional in the first case and annular in the second one. Although the effects over North Atlantic Climate can be similar, subjacent physical processes are very different, especially when spatial structures are compared. This work is focussed on the study of this spatial structure. Therefore a magnitude related to this structure is used: relative angular momentum (RAM). A comparative study between temporal series of both modes (indices) and RAM was performed in order to look for similarities, as well as correlation maps between RAM and Temperature and geopotential height data for the whole Hemisphere. Results show a pattern that is not restricted to the North Atlantic but does not show a purely annular character.