Researchers are embarking on an Atlantic Ocean expedition to investigate how climate change affects the Atlantic Meridional Overturning Circulation (AMOC), a critical ocean current that regulates global climate patterns.
The AMOC transports warm water northward and cold water southward, distributing heat across the planet. This system influences weather patterns from Europe to North America. Climate models predict the circulation will weaken substantially this century as greenhouse gases warm the atmosphere and freshwater from melting ice sheets dilutes ocean salinity, both factors that destabilize the current.
The urgency stems from observations showing the AMOC has already slowed by 15 percent since the mid-20th century. A complete collapse remains unlikely this century, but even gradual weakening carries consequences. Reduced heat transport northward could cool northern Europe while accelerating sea level rise along the U.S. Atlantic coast. Mediterranean circulation systems tied to AMOC also face disruption, with ripple effects on regional weather and marine ecosystems.
The expedition targets direct measurement of AMOC's strength and structure through water sampling, temperature profiles, and current velocity readings. These observations fill gaps in satellite and modeling data, providing ground truth for understanding how the system responds to warming. Researchers will examine how freshwater input from Greenland ice melt affects density gradients that drive the circulation.
The study builds on decades of monitoring networks like RAPID, which measures AMOC at 26 degrees north latitude. New field campaigns expand geographic coverage and temporal resolution to detect changes faster than models alone can predict.
Understanding AMOC's sensitivity to climate forcing matters for coastal communities dependent on its stabilizing effects. Accurate measurements now inform projections of regional climate shifts over coming decades, helping governments and populations prepare for potential shifts in rainfall patterns, hurricane intensity, and ocean conditions.