Dataset contains concentrations of Non-methane hydrocarbons in the deck incubation experiments over the Northwest Pacific Ocean (Station: E142-5, 142°E, 3°N).
Cruise Information:The cruise was conducted onboard the R/V 'Science' from October 15, 2019 to January 5, 2020Sample Collection and Analysis:Seawater samples were collected with syringe (100-mL) from the 20-L bottles (polycarbonate, Nalgene). The samples were packed into 120-mL brown-colored glass vials. Two drops of saturated HgCl2 solution were added to each sample to prevent potential microbial activity before the sample storage (Wu et al., 2021). The relevant characteristics of the marine samples were quantified by a gas chromatograph with a mass spectrum detector (GC-MSD) (Agilent 7890A/5975C, USA) equipped with a purge-and-trap (P&T) system in the case of selective ion monitoring (Wu et al., 2021).Deck Incubation Experiments:The deck incubation experiments were conducted with the seawater collected at station E142-5 (142°E, 3°N) during the 2019 Northwest Pacific cruise (2019.10.03-2020.01.05) to assess the responses of NMHCs formation to atmospheric aerosol deposition. Methods of the Incubation Experiments:Prior to incubation in 20-L bottles (polycarbonate, Nalgene), the seawater was filtered through a 200-µm nylon mesh to dislodge the zooplankton. We divided the incubation experiments into 3 groups (conducted in duplicate), including the control, aerosol treatments and acidic aerosol treatments. The aerosols sampled in the Northwest Pacific Ocean were dissolved in Milli-Q water and Milli-Q water (pH = 2) acidified with HCl to simulate the atmospheric deposition and acidified atmospheric deposition, respectively. This pH represents the acidity of aerosols that have been in contact with contaminated land air masses (Meskhidze et al., 2003; Nenes et al., 2011). Then, the aerosol samples were sonicated for 1 h and the suspensions were added to the filtered seawater to a final aerosol concentration of 2 mg L-1 in each incubation. There were no variations in seawater pH between the treatment and the control. A continuous supply of surface seawater was provided to maintain a constant temperature in the incubation systems.