Sea Level Dynamics In Northwest Africa: How Global Weather Patterns Link Multiple Continents Over Sub-annual To Decadal Time Scales

Abstract:

Sea-level dynamics along Northwest Africa are complex, poorly understood, and potentially show global-scale coupling of coastal water levels across the Atlantic Ocean- connecting the Americas and the Caribbean with Africa and Europe. And yet, sea level in North Africa is poorly understood, in part due to inequalities in the distribution of the global tide gauges network. This talk takes a data-analytics approach to understanding sea-level dynamics in North Africa, using a combination of European-run tide gauges, with satellite altimetry, and global weather and climate records. Results show that water level fluctuations across North Africa have long been linked to the intensity of the Azores High pressure weather system, which forces hemispheric winds that control the flow of water on and offshore. Rates of sea-level rise in Northwest Africa appears to be lower than the global average, in part because winds force water across the Atlantic Ocean, resulting in a hotspot for sea level rise along parts of the North America and the Caribbean. Despite this, the relationship between atmospheric fluctuations and North African sea-level rise appear to be changing, possibly because the global sea-level rise signal is overwhelming the meteorological forcings signal.