2026-10-09T19:27:16Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33684514 2026-09-13T02:38:39Z category_25906 item_type_3 month_year_09_2026

Article: Physical controls on dissolved N₂/Ar supersaturation in a windy estuary Zhihao Zhang (22996507) Physical oceanography bubble break-up gas exchange pattern Abstract: The ΔN₂/Ar method assumes physical perturbations to N₂ and Ar are synchronous, isolating biological N₂. In high-wind estuaries, however, bubble-mediated exchange diverges markedly among gases due to differences in solubility and partial pressure. Using winter observations in the Changjiang Estuary and a size-fractionated bubble model, we quantified air–sea exchange of N₂, O₂, and Ar. Small bubbles injected N₂ (1.92–14.45 mmol m⁻² d⁻¹) while large bubbles drove degassing (−24.06 to −4.21 mmol m⁻² d⁻¹). After correction, surface ΔN₂′ remained positive (10.38–18.64 μM), ΔO₂′ was 3.15–5.96 μM, and Ar stayed near equilibrium. Bubble-induced concentration offsets represented cumulative physical states accounting for one-third to one-half of observed surface ΔN₂, whereas instantaneous net fluxes reflected N₂ efflux at sampling. δ¹⁵N-N₂ correlated weakly with ΔN₂′, indicating atmospheric dominance. These findings provide a physical baseline for correcting nitrogen loss fluxes and demonstrate that a unified bubble framework constrains physical perturbations of N₂, O₂, and Ar. 2026-09-13T02:38:39Z Dataset Dataset 10.6084/m9.figshare.33684514.v1 https://figshare.com/articles/dataset/_b_Article_b_b_Physical_controls_on_dissolved_N_Ar_supersaturation_in_a_windy_estuary_b_/33684514 CC BY 4.0