Quantifying biological productivity and ocean carbon uptake in the NE Subarctic Pacific using observations and models

Earth system models are important tools to evaluate the current and future changes in the Earth’s environment. However, there are still many model disagreements about the patterns of carbon uptake by the oceans. This project will carry out field observations and computer modeling to determine the biological carbon uptake in the subarctic NE Pacific. This project will integrate various observations, for example, shipboard, autonomous float, satellite measurement, with high-performance computing. This project will help identify the causes of model biases and contribute to future model development. This study will engage local undergraduates as student assistants from nearby HBCUs in the Atlanta area and through summer REU program. The project is organized into three themes. First is the integration of in-vitro, in-situ and satellite observations of biological productivity. Second is the development of a regional carbon and ecosystem model. Third is characterization of spatial and temporal variability of biological productivity and air-sea carbon flux. The main objective is to quantify and reduce uncertainty in the regional biological carbon uptake through the combination of in situ and vitro methods and modeling. The field component will utilize the Line P time-series cruise in June 2024. Incubation experiments (13C, 15NO3, 15NH4) at five major stations will be conducted together with high-resolution underway O2/Ar measurements. This will quantify primary production and carbon export. To increase data coverage, autonomous floats and satellite observations will be incorporated. The new and existing observations will be used to validate and calibrate a new 3-dimensional regional ecosystem and carbon cycle model at eddy-resolving resolution. This model will be calibrated, then this model will be used to carry out multi-decadal simulation (1995-present). A suite of sensitivity model experiments will explore a wide range of scientific questions and hypotheses including the role of iron dynamics, mesoscale physical features, climate modes, and extreme events such as marine heat waves. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.