New Study Quantifies 50-Year Warming Trend
A new study quantifies the warming trend in the Gulf of Mexico’s ocean heat content over the past 50 years. The study, published in the American Meteorological Society’s Journal of Climate, was a joint effort between scientists at NCEI and the Northern Gulf Institute (NGI), a NOAA Cooperative Institute. The study shows that waters closest to the surface in the Gulf of Mexico have increased at a rate approximately twice that of the global ocean in the decades between 1970 and 2020.
Due to its large size and the complex current system, the Gulf of Mexico is home to important marine species including red snapper, Florida Manatee, and Rice’s whales. The Gulf also provides valuable economic benefits to the countries that border it—the United States, Mexico, and Cuba—including shipping, oil and gas, and fisheries. Understanding the changes in this oceanic basin are vital to its long-term ecological and economic health.
As a part of the global ocean, the Gulf of Mexico plays a critical role in Earth’s climate system by absorbing and storing heat. The top few meters of the global ocean store as much heat as Earth’s entire atmosphere. The total amount of heat energy stored by the oceans is called ocean heat content. Knowing how much heat energy the ocean absorbs and releases is essential for understanding and modeling global climate.
To estimate the change in the Gulf of Mexico’s ocean heat content, NCEI and NGI scientists analyzed 192,890 temperature profiles collected from 1950–2020 in the Gulf of Mexico and publicly available in the World Ocean Database. Collected by instruments such as gliders, Argo floats, and CTDs (Conductivity-Temperature-Depth), each profile provides a snapshot of oceanographic conditions over multiple depths at one time from one location.
The data show that the Gulf of Mexico sea surface temperature (SST) increased approximately 1.0°C (1.8°̊F) between 1970 and 2020, equivalent to a warming rate of approximately 0.19°C (0.34°F) per decade. The Gulf of Mexico warmed at twice the rate of warming in the global ocean near the sea surface. Warming occurs at all studied depths from the sea surface to bottom with the largest warming rates found in the upper 50 meters (164 feet).
Understanding how this major climate driver affects the Gulf of Mexico is necessary for effective management. Oceanic warming can exacerbate many of the threats to the Gulf of Mexico ecosystem including sea level rise and hypoxia or the “dead zone.” Warming also increases the intensity of hurricanes, escalating the damage to coastal communities and the loss of wetlands.
NCEI plays a critical role in NOAA’s strategic goals by maintaining the most comprehensive public archive of environmental data in the United States and equitably distributing scientific products that drive decision-making across sectors, supporting the new blue economy and climate-informed strategies.
Wang, Z., Boyer, T., Reagan, J., & Hogan, P. (2023). Upper Oceanic Warming in the Gulf of Mexico between 1950 and 2020, Journal of Climate (published online ahead of print 2023). Retrieved January 27, 2023, from https://journals.ametsoc.org/view/journals/clim/aop/JCLI-D-22-0409.1/JCLI-D-22-0409.1.xml