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

Yanyun Liu, University of Miami, yanyun.liu@noaa.gov (Presenter)
Sang-ki Lee, University of Miami, sang-ki.lee@noaa.gov
Barbara A Muhling, University of Miami, barbara.muhling@noaa.gov
John T Lamkin, NOAA-Fisheries, john.lamkin@noaa.gov
David B Enfield, University of Miami, david.enfield@noaa.gov
Gustavo J Goni, AOML/NOAA, gustavo.goni@noaa.gov
Frank E Muller-Karger, University of South Florida, carib@marine.usf.edu
Mitchell A Roffer, Roffer's Ocean Fishing Forecasting Service, Inc., roffers@bellsouth.net

The IPCC-AR4 climate model simulations under SRESA1B scenario project that the upper ocean temperature in the Gulf of Mexico (GoM) may increase by approximately 2oC between 2000 and 2100. However, the IPCC-AR4 climate models have typical spatial resolution of about one degree. Thus, the inflow-outflow system of the GoM that connects the Yucatan Current, Loop Current, and Florida Current are poorly resolved. Here, the potential impact of future anthropogenic global warming on the Gulf of Mexico (GoM) is examined by using a downscaled high-resolution ocean model constrained with the surface forcing fields, initial and boundary conditions obtained from the IPCC-AR4 model simulations under A1B scenario. The simulated volume transport by the Loop Current (LC) is reduced by 20 - 25% during the 21st century, consistent with a similar rate of projected reduction in the Atlantic Meridional Overturning Circulation. The effect of the LC in the present climate is to warm the GoM, therefore the reduced LC and the associated weakening of the warm LC eddy have a cooling impact in the GoM, particularly in the northern basin. Therefore, the northern GoM is characterized as the region of minimal warming. Low-resolution models, such as the IPCC-AR4 models, underestimate the reduction of the LC and its cooling effect, thus fail to simulate the reduced warming feature in the northern GoM. The potential implications of the reduced warming in the northern GoM on pelagic fish species and their spawning patterns are also discussed.

Presentation Type:  Poster

Session:  Science in Support of Decision Making   (Wed 10:00 AM)

Associated Project(s): 

• Related Activity

Poster Location ID: 192