Jet Stream Poleward Migration Leads to Marine Primary Production Decrease

Jet streams (JS) are high-speed upper-tropospheric winds that have significant influence on weather and climate. As anthropogenic climate change alters temperature gradients, subtropical JS are projected to shift poleward, which can have unforeseen impacts on midlatitude Earth systems. Here, we demonstrate for the first time the impact of the steady poleward migration of the Northern Hemisphere subtropical JS on marine primary production (MPP). This northward migration lines up with a consistent decrease in MPP over the last two decades in the Northwestern Mediterranean Sea. While the primary influence of JS position on MPP is seasonal, its impact extends to non-seasonal components as well. These findings highlight the direct consequences of JS latitudinal shifts on marine ecosystems, indicating potential cascading effects driven by climate change.