CoAuthors

Richard Ray (NASA-GSFC, USA); Brian Beckley (SGT Inc, USA)

Changes of the North Atlantic coastal mean sea level and its increased seasonal cycle over different regions using satellite radar altimetry and tide gauge data have been previously confirmed and validated. This study confirms the seasonal cycle variability and addresses the changes in the annual amplitude of the seasonal cycle of both coastal and open sea level regions in the North Atlantic, such as the Gulf of Mexico and the Gulf Stream region. The physical climate forcings responsible for observed increased annual amplitude of sea level during the most recent years are explored by analyzing the connection between the variability in the annual amplitude of sea level and a set of oceanic and synoptic parameters (i.e., sea surface temperature, air temperature, mean sea level pressure, wind curl, evaporation, precipitation, fresh water flux, mesoscale eddies, etc.), including the ARGO parameters of temperature and salinity. The changes observed in the North Atlantic seasonal sea level cycle have very strong correlation to changes in the investigated forcing parameters, especially with temperature parameters during early cold season, and with mean sea level pressure and freshwater flux parameters in later warm season for most regions in the Western Atlantic. Better understanding of these forcing parameters in connection to the seasonal sea level cycle change could offer improved seasonal to inter-annual prediction of sea level variations.