Basin-scale features of global sea level trends revealed by altimeter data from 1993 to 2013

In this study, altimeter sea level data (from http://www.aviso.oceanobs.com) are used to study large scale, non-uniform patterns of sea level trends of the world's major oceans from 1993 to 2013. The three major oceans: the Pacific Ocean, the Indian Ocean and the Atlantic Ocean, are all rising, with different large-scale patterns. The Indian Ocean has the greatest mean sea level rise trend at 4.06 mm/year. Standard deviations of the spatial distribution of Pacific Ocean and Indian Ocean sea levels have been increasing during the last two decades while those of the Atlantic Ocean have been decreasing. By defining a new index, the volume centroid of the upper ocean layers, we find that, during the past two decades, the meridional volume centroids of the three major oceans have been moving southward. The zonal volume centroids of the Pacific Ocean and the Indian Ocean are closely related, exhibiting almost opposite phases during the last two decades. The long-term trends of the zonal volume centroids of the Pacific and Indian Oceans reveal that the areas around the western Pacific warm pool are at great risk of extreme sea level rise.