Work

Influences of Typhoon Size and Translation Speed on Chlorophyll a Response in the Oligotrophic Northwestern Pacific

Year: 2025

Type: article

Abstract: Tropical cyclones drive episodic phytoplankton blooms in nutrient‐depleted oceans, but the roles of storm intensity, size, and translation speed remain unclear. Using satellite‐derived chlorophyll a (Chl a ) and typhoon data (2002–2023) from the oligotrophic Northwestern Pacific, we show that typhoon size (R34, radius of 34 kt winds) and translation speed, rather than intensity, dominate Chl a responses. Chl a bursts were concentrated within 2° of the typhoon center and peaked 1–6 days after passage. The strongest Chl a responses occurred with slow, large typhoons, while fast, small typhoons induced the weakest response. When translation speeds were below 4 m/s, both R34 and speed influenced the Chl a response; above 4 m/s, R34 was the primary driver. These results redefine the relative contributions of typhoon parameters to marine productivity, emphasizing size as a critical yet overlooked factor.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl116812