New production (NP) and net community production (NCP) measurements are often used as estimates of carbon export potential from the mixed layer of the ocean, an important process in the regulation of global climate. Diverse methods can be used to measure NP and NCP, from research vessels, autonomous platforms, and remote sensing, each with its own set of benefits and uncertainties. The various methods are rarely applied simultaneously in a single location, limiting our ability for direct comparisons of the resulting measurements. In this study, we evaluated NP and NCP from thirteen independent datasets collected via in situ, in vitro, and satellite-based methods near Ocean Station Papa during the 2018 Northeast Pacific field campaign of the NASA project EXport Processes in the Ocean from RemoTe Sensing (EXPORTS). Altogether, the datasets indicate that carbon export potential was relatively low (median daily averages between −5.1 and 12.6 mmol C m−2 d−1), with most measurements indicating slight net autotrophy in the region. This result is consistent with NCP estimates based on satellite measurements of sea surface temperature and chlorophyll a. We explored possible causes of discrepancies among methods, including differences in assumptions about stoichiometry, vertical integration, total volume sampled, and the spatiotemporal extent considered. Results of a generalized additive mixed model indicate that the spatial variation across platforms can explain much of the difference among methods. Once spatial variation and temporal autocorrelation are considered, a variety of methods can provide consistent estimates of NP and NCP, leveraging the strengths of each approach.

See Niebergall, A., Traylor, S. Huang, Y., Feen, M., Meyer, M. G., McNair, H. M., Nicholson, D., Fassbender, A. J., Omand, M. M., Marchetti, A., Menden-Deuer, S., Tang, W., Gong, W., Tortell, P., Hamme, R., Cassar, N. 2023. Evaluation of new and net community production estimates by multiple ship-based and autonomous observations in the Northeast Pacific Ocean. Elementa: Science of the Anthropocene (2023) 11 (1): 00107.

Spatio-temporal coverage of measurement methods for net community production and new production. Conceptual diagram showing the spatio-temporal coverage of net community production (NCP) and new production (NP) measurements evaluated in this study. Lower boundaries represent the spatial and temporal resolution of each measurement method or platform, while upper boundaries represent spatial and temporal coverage for each method or platform. This conceptual figure (not drawn to scale) is meant to show the spatial and temporal coverage of the methods in general; therefore, the boundaries do not necessarily represent the coverage of the individual instruments as deployed in this study. The faded spatial boundary for satellites indicates a larger spatial coverage than fits the bounds of this figure.