The Gulf of Mexico region is home to a unique current: The Loop Current (LC). The current moves through the Yucatan Peninsula goes northward to the Gulf of Mexico, then goes through the Strait of Florida to the Atlantic and joins Gulf Stream.
States of the Loop Current
- Retracted State - The current turns sharply east, off the northern Cuba, goes out Florida State.
- Extended State - The current goes north to about 24 degrees north, before anticyclonically (clockwise) turning east, travels on western Florida coast then exits through Florida Strait.
- Eddies - In the currents extended state it will shed warm-core anticyclonic eddies. These eddies are roughly 300 kilometers across, 500 to 1000 meters deep. These eddies can keep a speed of 4 knots after detaching from the main LC.
The LC has a current speed of about 2-4 knots (1.03 m/s to 2.06 m/s).
Ocean Currents Forecast (Maps displaying the latest gridded surface oceanographic forecast model guidance for the global ocean from the NOAA/NWS Global Real-Time Ocean Forecast System (GRTOFS).)
Map of salinity and currents
Arrows (white: currents size represents speed intensity)
Shows very similar salinity for most of Gulf with the exception of the Mississppi River mouth.
Map of temperature and currents
Arrows (black: currents size represents speed intensity)
Very warm and uniform temperature in the Gulf.
Explanation of the Loop Current
Uncovering Hidden Currents in the Gulf of Mexico
The Gulf Stream Explained
Eddies are named just like tropical cyclones, winter storms, and hurricanes. Cold core eddies can also form off the edges of the LC but are smaller then warm core eddies. Shedding can occur over a period of a couple of weeks to 19 months, with an average of 8 to 9 months.
Why should we care about currents?
Deepwater Horizon
https://www.theguardian.com/world/2010/dec/26/eyewitness-2010-review-of-the-year
The Deepwater Horizon oil spill was hard to maintain due to the lack of sufficient in-situ data of deep water currents, which would have been useful for containing the spill. Models and data assimilation did not have detailed information of deep waters, which could have given first responders better data to make informed decisions.
Hurricane Katrina
https://en.wikipedia.org/wiki/Hurricane_Katrina
From book: Understanding and Predicting the Gulf of Mexico Loop Current Critical Gaps and Recommendations
The way the LC restracts and extends has a significant affect on hurricane intensity. When hurricanes pass over warm-core eddies they can potentially increase in intensity as warm surface water fuels hurricanes. Hurricane Katrina which devistated the Gulf Coast states is a prime example of this hurricane-LC relationship but is far from the only example.
