LOOP Current variability - its relation to meridional overturning circulation and the impact of Mississippi discharge

• Applicant: Professor Dr. Dirk Nürnberg
• Subject Area: Palaeontology
• Term: from 2007 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 42144659

The Loop Current and its associated eddy-shedding is mediating the oceanic heat and salt flux from the Caribbean into the Atlantic Ocean. Its interference with Mississippi discharge are critical for both, regional climate in the Gulf of Mexico and large-scale transports towards high northern latitudes. By combining state-of-the-art paleoceanographic and meso-scale eddy-resolving numerical modeling techniques, we examine the Loop Current dynamics and hydrographic changes in the Gulf during the last deglaciation and interglacials MIS 1 and 5 with a special focus on the impact of Mississippifreshwater discharge.Deglacial SST and SSS changes in the Gulf appear to be rather continuous and significantly larger than in the Caribbean/Atlantic Warmpool. Surface freshening occurs during glacial periods and deglacial cool events and is related to enhanced and eastward directed Mississippi river discharge. In this project, we relate the continuous and stronger deglacial surface warming in the Gulf to the onset and increase of eddy-shedding by the Loop Current related to deglacial sea level rise, Yucatan Strait throughflow velocity, and changes in the atmospheric circulation. Further, we investigate enhancedfluvial discharge on the circulation in the Gulf of Mexico.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1266: Integrated Analysis of Interglacial Climate Dynamics (INTERDYNAMIC)
• Participating Persons: Professor Dr. Carsten Eden; Dr. Sascha Flögel; Dr. Joachim Schönfeld; Professor Dr. Ralf Tiedemann