Future Impact of Weakening Atlantic Thermohaline Circulation on the Loop Current in the Gulf of Mexico
To have a detailed and reliable assessment of the regional impact of global climate change on the ocean circulation and water mass characteristics of GoM, dynamic downscaling of the IPCC-AR4 climate models to the GoM region is performed by using the Hybrid Coordinate Ocean Model coupled to Atmospheric Mixed Layer (HYCOM-AML). The model domain for the HYCOM-AML contains the Atlantic Ocean between 100E and 20E bounded north and south by 50N and 20S, respectively. A multi-level nested-domain system with about 10km resolution is used in the GoM and lower resolution elsewhere. The regional HYCOM-AML will be initialized and integrated for each decade-averaged period between 2000 and 2100 by using the atmospheric forcing and initial-boundary conditions derived from the IPCC-AR4 climate model simulations under three CO2 emission scenarios. The impact of the climate change on the strength, position and eddy characteristics of the Loop Current is assessed. Potential implications of the Loop Current changes, under a range of climate change scenarios, on bluefin tuna spawning patterns are also discussed.