Significant Reduction of the Loop Current in the 21st Century and Its Impact on the Gulf of Mexico

This study examines the potential impact of future anthropogenic global warming on the Gulf of Mexico by using a downscaled high‐resolution ocean model constrained with the surface forcing fields and initial and boundary conditions obtained from the IPCC‐AR4 model simulations under A1B scenario. The simulated volume transport by the Loop Current is reduced considerably by 20–25 percent during the 21st century, consistent with a similar rate of reduction in the Atlantic Meridional Overturning Circulation. The effect of the Loop Current in the present climate is to warm the Gulf of Mexico, therefore the reduced Loop Current and the associated weakening of the warm Loop Current eddy have a cooling impact in the Gulf of Mexico, particularly in the northern basin. Due to this cooling influence, the northern Gulf of Mexico is characterized as the region of minimal warming. Low‐resolution models, such as the IPCC‐AR4 models, underestimate the reduction of the Loop Current and its cooling effect, thus fail to simulate the reduced warming feature in the northern Gulf of Mexico. The potential implications of the reduced warming in the northern Gulf of Mexico on pelagic fish species and their spawning patterns are also discussed.

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Liu, Y., S.-K. Lee, B.A. Muhling, J.T. Lamkin, and D.B. Enfield. Significant reduction of the Loop Current in the 21st century and its impact on the Gulf of Mexico. Journal of Geophysical Research. 2012.