Madden-Julian oscillation winds excite an intraseasonal see-saw of ocean mass that affects Earth's polar motion

Strong large-scale winds can transfer their energy to the ocean floor, causing an almost immediate intraseasonal barotropic (depth-independent) ocean response. The intense winds of the Madden-Julian Oscillation (MJO) over the Maritime Continent create significant intraseasonal, basin-wide barotropic sea level changes in the tropical Indian Ocean. This study, using a numerical model and in-situ bottom pressure recorders, demonstrates that the combined barotropic response of the Indian and Pacific Oceans to these winds results in an intraseasonal see-saw of oceanic mass in the Indo-Pacific basin. This large-scale mass shift is surprisingly rapid, with the Indo-Pacific basin's mass field adjusting to the MJO within days. This MJO-induced see-saw measurably affects Earth's polar axis motion, particularly during the strong see-saw of early 2013.

M. Afroosa, B. Rohith, Arya Paul, Fabien Durand, Romain Bourdallé-Badie, P. V. Sreedevi, Olivier de Viron, Valérie Ballu, S. S. C. Shenoi