Gulf Stream Transport Of Water Slows Down Indicating Weakening Due To Climate Change, Study Says

A new study suggests that the Gulf Stream's transfer of water through the Florida Straits has slowed by 4% over the last four decades, with 99% certainty that this slowing is greater than expected from random chance.

The Gulf Stream is a strong ocean circulation off the coast of the United States East Coast and North Atlantic Ocean circulation-plays a vital role in weather and climate, and a weakening could have serious consequences.

Importance of understanding Gulf Stream

According to the journal published in Geophysical Research Letters, understanding the changes in Gulf Stream is important.

The Gulf Stream has an impact on regional weather, climate, and coastal conditions such as European surface air temperature and precipitation, coastal sea level along the Southeastern United States, and North Atlantic hurricane activity.

The Florida Straits, which connects the Florida Keys, Cuba, and the Bahamas, have been the location of numerous ocean observation missions since the 1980s.

Only in the last ten years has this major trend appeared from the dataset, providing the first definitive evidence for a recent multidecadal drop in this climate-relevant component of ocean circulation.

The research also noted that identifying variations in Gulf Stream movement is important for assessing if parts of the large-scale North Atlantic circulation have changed and how the ocean is feeding back on climate.

"This is the strongest, most definitive evidence we have of the weakening of this climatically-relevant ocean current," said Chris Piecuch, a physical oceanographer with the Woods Hole Oceanographic Institution, who is lead author of this study.

Weaking of the gulf

Piecuch stressed that while they are certain that a weakening state is occurring, they cannot identify how much of it is due to climate change or whether it is a natural variation.

To determine the movement of water through the Florida Straits since 1982, researchers used Bayesian modeling to incorporate thousands of data points from three distinct data sets-undersea cables, satellite altimetry, and in situ observations.

Probability is used in Bayesian modeling to indicate uncertainty within a model.

The Bayesian model results showed clear evidence of long-term change. Furthermore, researchers discovered that excluding any of the data sets from the analysis suggested weakness. According to the paper, this illustrates that transport weakening is a common signal that is independent of any particular data set.

Piecuch used a courtroom analogy to highlight the significance of the process. " When you are making your case, you need more than one witness, and you ideally want a collection of independent witnesses whose statements-when taken together-paint a consistent and coherent story," he said.

A recent study also shows that the Gulf Stream system could fail in 2025.

Scientists believe that shutting down the critical ocean currents known as the Atlantic Meridional Overturning Circulation (Amoc) will have catastrophic climate consequences.

If global carbon emissions are not decreased, the analysis predicts a collapse between 2025 and 2095, with a central estimate of 2050.

Evidence from previous collapses implies temperature shifts of 10 degrees Celsius in a few decades, albeit during cold ages.

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