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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. [ABSTRACT FROM AUTHOR]

In recent years, the impact of aerosols on marine ecology has received increasing attention. However, the research on this aspect mainly focuses on the aspect of dust aerosols. As an important source of dissolved iron (Fe) and carbon in the ocean, biomass burning aerosol deposition has an extremely important impact on Marine ecosystem. In this study, a forest fire episode was investigated using satellite observations and the WRF-Chem model from 23 to 26 April 2014. Particular attention was paid to the biomass burning effects on the particulate organic carbon (POC) and chlorophyll-a (Chl-a) concentration in the subarctic North Pacific Ocean (SNPO). The geopotential height and CALIPSO results indicated that smoke (biomass burning) aerosols were transported from Northeast Asia to the SNPO in 2 days with the effect of a low-pressure system in Mongolia. The WRF-Chem model also confirmed that CO spread southeastward and reached the SNPO in two days. Wet deposition of smoke aerosols occurred over the research region (RR) (40°-50°N, 150°-160°E) in the SNPO from 25 to 26 April 2014, and both the Chl-a concentration and POC over the RR increased nearly five times one day after the deposition of smoke aerosols. These significant increases were one order of magnitude higher than those that occurred in response to the dust episode, and the time delay was also shorter. This result indicates that smoke aerosols emitted by biomass burning lead to an increase in phytoplankton and POC once deposited and dissolved in the surface ocean, biomass burning emissions may have a more important effect in marine productivity and even ocean carbon cycles for some high nutrient and low chlorophyll (HNLC) regions compared with dust aerosols. • Trans -Pacific biomass burning and its effect on ocean productivity were studied. • The effect of smoke aerosols on Chl-a concentration and POC are stronger than dust. • Biomass burning leads to a sharply increase in Chl-a concentration and POC. [ABSTRACT FROM AUTHOR]