Afroosa M., Rohith B., Paul A., Durand Fabien, Bourdalle-Badie R., Sreedevi P. V., de Viron O., Ballu V., Shenoi S. S. C. (2021). Madden-Julian oscillation winds excite an intraseasonal see-saw of ocean mass that affects Earth's polar motion. Communications Earth and Environment, 2 (1), p. 139 [8 p.].
Titre du document
Madden-Julian oscillation winds excite an intraseasonal see-saw of ocean mass that affects Earth's polar motion
Afroosa M., Rohith B., Paul A., Durand Fabien, Bourdalle-Badie R., Sreedevi P. V., de Viron O., Ballu V., Shenoi S. S. C.
Source
Communications Earth and Environment, 2021,
2 (1), p. 139 [8 p.]
Strong large-scale winds can relay their energy to the ocean bottom and elicit an almost immediate intraseasonal barotropic (depth independent) response in the ocean. The intense winds associated with the Madden-Julian Oscillation over the Maritime Continent generate significant intraseasonal basin-wide barotropic sea level variability in the tropical Indian Ocean. Here we show, using a numerical model and a network of in-situ bottom pressure recorders, that the concerted barotropic response of the Indian and the Pacific Ocean to these winds leads to an intraseasonal see-saw of oceanic mass in the Indo-Pacific basin. This global-scale mass shift is unexpectedly fast, as we show that the mass field of the entire Indo-Pacific basin is dynamically adjusted to Madden-Julian Oscillation in a few days. We find this large-scale ocean see-saw, induced by the Madden-Julian Oscillation, has a detectable influence on the Earth's polar axis motion, in particular during the strong see-saw of early 2013. Intense winds over the Maritime Continent associated with the Madden-Julian Oscillation lead to a large-scale redistribution of oceanic mass in the Indo-Pacific basins, and have a noticeable impact on the Earth's angular momentum.
