Cause of Substantial Global Mean Sea Level Rise Over 2014–2016

Abstract

Abstract Global mean sea level rose by 15 mm over June 2014 – May 2016. This rise is 7 mm larger than the 8 mm increase associated with the long‐term trend of 4 mm/yr estimated over 2006–2016. Using a combination of satellite gravimetry data and in situ measurements, we find that 20% of this rise is explained by ocean thermal expansion and 80% by an ocean mass increase, the latter being largely correlated with an equivalent terrestrial water storage (TWS) decrease. Half of the global ocean mass increase during that period can be attributed to the South American continent where we find a significant contribution of the TWS over the Amazon basin (5 mm). This TWS change between oceans and continents occurred during two El Nino events: one aborted in 2014–2015 and an extreme event in 2015–2016 which affected precipitation patterns, especially over the equatorial Pacific ocean and over South America.

Keywords

• global mean sea level
• satellite altimetry
• GRACE
• argo data
• interannual variability