Sea level budget in the East China Sea inferred from satellite gravimetry, altimetry and steric datasets

Abstract

The regional sea level budget in the East China Sea (ECS) was investigated with satellite gravimetry, altimetry, steric and sediment datasets over the period from April 2002 to December 2022. The “sediment effect” due to the difference between the change in sediment mass and the displaced original seawater should be removed from the total mass change observed by satellite gravimetry data to accurately estimate the manometric sea level change associated with the variations in seawater mass. We divided the whole ECS region into sediment and nonsediment areas. After accurately estimating the manometric sea level change, specifically the change in seawater mass, the ECS regional sea level budget could be closed within a 2-sigma uncertainty. Our results revealed that the linear trends of the regional mean sea level change in the ECS can be attributed mainly to the change in the manometric sea level (3.06 mm/year), followed by the steric component (0.44 mm/year), which contributes only ~12.57% of the total ECS regional mean sea level change rate observed via satellite altimetry. The linear trend residuals of the ECS regional sea level budget ranged from −0.12 mm/year to 0.10 mm/year, all within a 2-sigma uncertainty.