The effect of lower sea level on geostrophic transport through the Florida Straits during the last glacial maximum

• Main Author: Ionita, Dana
• Other Authors: Lynch-Stieglitz, Jean, Di Lorenzo, Emanuele, Earth and Atmospheric Sciences, Annalisa Bracco, Robert Black
• Format: Thesis
• Language: unknown
• Published: Georgia Institute of Technology 2009
• Subjects: Geostrophic transport; Florida Straits; LGM; Last Glacial Maximum; Sea level; Geostrophic currents; Florida; Straits of; North Atlantic
• Online Access: http://hdl.handle.net/1853/28200

We investigate the effect of a 120 meter sea level drop on transport through the Caribbean Sea and the Florida Straits during the Last Glacial Maximum (LGM) relative to the present, using the Regional Ocean Modeling System (ROMS). A geostrophic transport estimate for the Florida Straits suggests the LGM Florida Current was weaker than today by one third, inferring a likely decrease in the North Atlantic overturning circulation by 12-15 Sv. A possible impact of a shallower LGM Florida Straits sill depth on the Florida Current has been suggested. Our model results show that the volume transport through the Florida Straits is slightly reduced in a lower sea level model simulation when compared to a control sea level simulation (34.8 ± 2.0 Sv vs. 39.8 ± 2.3 Sv). The difference in transport is of the order of 5 Sv, representing a maximum limit to the LGM flow reduction due to sea level change. Therefore the change in sill depth between the LGM and the present is unlikely to have been a cause of the entire observed flow reduction. M.S.