Description: Dataset contains concentrations of non-methane hydrocarbons in the atmosphere over the Northwest Pacific Ocean (2017-10 to 2017-12).

Description: Dataset contains concentrations of Non-methane hydrocarbons in the deck incubation experiments over the Northwest Pacific Ocean (Station: E142-5, 142°E, 3°N).

Description: Dataset contains environmental parameters and concentrations (pmol L-1) and fluxes (nmol m-2 d-1) of non-methane hydrocarbons in the Northwest Pacific Ocean (2017-10 to 2017-12).

Description: In this work, we used field investigations in the Northwest Pacific Ocean and determined the surface seawater distributions of atmospheric non-methane hydrocarbons (NMHCs) and their oceanic sources. We conducted deck incubation experiments to investigate the responses of NMHCs to atmospheric aerosol deposition. The geographical distributions of NMHCs in seawater were related to ocean currents by controlling nutrient levels and phytoplankton biomasses and communities. The high nutrient levels caused by the Oyashio Current promoted the concentration of biogenic isoprene. In addition, the transformation of predominant phytoplankton also affected the isoprene formation. The increasing proportion of diatoms (68%) in the Oyashio Current and Kuroshio Extension contributed significantly to isoprene generation, and isoprene was 3-7 fold higher than that in other areas. Corresponding to seawater, the atmospheric NMHCs apart from isoprene displayed upward trends with increasing latitude. The deck incubation experiments revealed that the dynamic changes in phytoplankton biomass and community incurred by aerosol and acidic aerosol deposition were significantly accelerated isoprene production. However, no obvious responses of the other six NMHCs to atmospheric aerosol deposition were found in the incubation studies. Both ocean current movements and atmospheric deposition jointly influenced the generation and release of isoprene in the Northwest Pacific Ocean.

Description: Marine isoprene plays a crucial role in the formation of secondary organic aerosol within the remote marine boundary layer. Due to scarce field measurements of oceanic isoprene and limited laboratory-based studies of isoprene production, assessing the importance of marine isoprene on atmospheric chemistry and climate is challenging. Calculating in-field isoprene production rates is a crucial step to predict marine isoprene concentrations and the subsequent emissions to the atmosphere. The distribution, sources, and dominant environmental factors of isoprene were determined in the Northwest Pacific Ocean in 2019. The nutrient enrichment in the Kuroshio Oyashio Extension (KOE) surface seawater, driven by the upwelling and atmospheric deposition, promoted the growth of phytoplankton and elevated the isoprene concentration. This was confirmed by observed responses of isoprene to nutrients and aerosol dust additions in a ship-based incubation experiment, where the isoprene concentrations increased by 70% (t = 4.417, p 〈 0.001) and 35% (t = 2.387, p 〈 0.05), respectively. Biogenic isoprene production rates in the deck incubation experiments were positively related to chlorophyll a, temperature, and solar radiation, with an average production of 7.33 +/- 4.27 pmol L (-1) day (-1). Photochemical degradation of dissolved organic matter was likely an abiotic source of isoprene, contributing to approximately 14% of the total production. Driven by high isoprene production and extreme physical disturbance, the KOE showed very high emissions of isoprene of 46.0 +/- 13.0 nmol m(-2) day (-1), which led to a significant influence on the oxidative capacity of the local atmosphere.