The biological oxygen (O2) saturation anomaly ΔO2/Ar is a tracer for net community production (NCP) in marine surface waters, with argon (Ar) normalization used to correct for physical effects on O2 supersaturation. Ship-board mass spectrometry has been used for ΔO2/Ar measurements, but this approach may not be accessible to many research groups. Here, we present a proof-of-concept for NCP estimates based on underway measurements of ΔO2/N2, which can be obtained from deployments of O2-Optodes and gas tension devices (GTD). We used a one-dimensional mixed layer model, validated against field observations, to evaluate divergence in ΔO2/Ar and ΔO/N2 resulting from differences in the sensitivity of Ar and nitrogen (N2) to various physical processes. Changes in sea surface temperature and responses in air-sea exchange most strongly decouple surface Ar and N2 with additional excess N2 associated with bubble-injection during high-wind conditions and vertical mixing in regions of elevated subsurface N2. In contrast, biological N2-fixation has a negligible contribution to the observed divergence between Ar and N2. Based on readily available environmental data, we present an approach to correct for Ar and N2 differences, yielding a new tracer, N2’, that is a near analog of Ar. We show that ΔO2/N2’ provides an excellent approximation to ΔO2/Ar, and that uncertainty and biases in ΔO2/N2’ are small relative to other errors in NCP calculations. Our results demonstrate the potential for ΔO2/N2’ measurements to expand NCP estimates from oceanographic research surveys, vessels of opportunity or autonomous surface vehicles.