资源环境科技发展态势分析平台

A profound westward shift in atmosphere-ocean variability in the tropical Pacific is observed when 2000-2017 is compared to 1979-1999. This westward displacement is associated with changes in oceanic Kelvin wave activity along the equator, especially a remarkable reduction in the eastern Pacific (175 degrees-145 degrees W). This coincides with a weakening of low-level westerly winds in this region, and a westward shift of low-level easterly winds in the central and eastern tropical Pacific, as well as decreased variability of vertical entrainment, vertical diffusion in the ocean mixed-layer in the eastern Pacific. The observed enhancement of the zonal contrast of the mean state across the tropical Pacific seems to be associated with the westward shift of climate variability along the equator. This systematically westward shift of the atmosphere-ocean variability in the tropical Pacific alters the impact of the tropical Pacific on extra-tropical climate.