Long-Range Transport of a Dust Event and Impact on Marine Chlorophyll-a Concentration in April 2023

Abstract

Dust aerosols serve as a crucial nutrient source to the oceans and profoundly influence marine ecosystems. This study used satellite and ground observations to explore a strong dust event on 9–13 April 2023, emanating from the Gobi Desert, shared by Mongolia and China’s Inner Mongolia region. We investigated the deposition of dust particles and their effects on marine phytoplankton communities. Our findings revealed that the dust event was intense, enduring, and expansive, illustrated by hourly PM10 concentrations peaking at 5055 µg/m3 near the source and consistently exceeding 1000 µg/m3, even at considerable distances. The dust traveled along two different trajectories and was deposited in the same area of the Northwest Pacific. Total dust deposition in the study area (37°N–42°N, 145°E–165°E) was 79.88 mg/m2 from 13 to 18 April, much higher than the 2019–2022 average deposition of 33.03 mg/m2 for the same period. With dust deposition, the observed mean chlorophyll-a concentrations in the area increased to 2.78 mg/m3 on 14 April, an extraordinary 692% increase above the long-term average. These results highlight the profound impact of dust on the productivity of marine phytoplankton communities by inputting more nutrients into the ocean through different pathways.