Award: OCE-1026607

Intellectual Merit We have made important strides forward in understanding the response of a major Eastern Boundary Current upwelling ecosystem to environmental forcing on multiple time and space scales. Our research has made fundamental contributions in the realms of: - Climate change impacts on marine ecosystems, including the effects of changes in stratification, dissolved oxygen, and ocean fronts on diverse elements of the pelagic food web, ranging from prokaryotic organisms, eukaryotic phytoplankton, micro- and meso-zooplankton, and mesopelagic fishes, to seabirds. Our studies have drawn on the 68-year record of CalCOFI observations to reveal important ecosystem variations on multiple time scales, including: (1) Interannual variations, especially associated with El Nino-Southern Oscillation and the Warm Anomaly of 2014-15; (2) Multi-decadal variations, dominated by the Pacific Decadal Oscillation and North Pacific Gyre Oscillation; (3) Long-term secular trends, including changes in dissolved oxygen and nutrient stoichiometry. - The dynamics and ecological consequences of (sub)mesoscale ocean fronts. We have illustrated commonalities and differences across different ocean fronts studied on our intensive, Lagrangian-based process cruises in the CCE-LTER region. We have supplemented ship-based experimental studies with novel autonomous glider-based measurements of biophysical fronts and satellite remote-sensing studies of temporal changes in frontal occurrence. We have shown that (sub)mesoscale ocean fronts have consequences disproportionate to their geographic extent, because they are often regions of elevated phytoplankton and zooplankton biomass; they can be accompanied by pronounced changes in food web structure, signified by marked shifts in floristic and faunistic composition; and they are typically sites of enhanced predator and prey abundances, hence sites of increased encounter rates. Our satellite studies have shown that frontal features have increased in occurrence over the past 2-3 decades, suggesting that these features will increasingly influence California Current Ecosystem food webs in the future. - Ocean biogeochemical cycling, including the novel finding that ocean fronts can be regions of 2-3 fold increased vertical export of carbon, via two primary mechanisms: enhanced gravitational settling, combined with ocean subduction that increases carbon export out of the surface ocean in both particulate and dissolved phases. We have also developed one of the most comprehensive nitrogen isotope budgets for any ocean region and the only one available for a coastal upwelling region. - Development of high quality measurement methods for Ocean Acidification studies, including continuous underway pCO2 and pH measurements from CalCOFI cruises and the development of geochemical proxy relationships that permit carbonate system variables to be estimated from autonomous measurements made by ocean gliders and interdisciplinary moorings. - Differentiating pelagic ecosystem consequences of the strong Pacific warm anomalies of 2014-15 from those of El Niño 2015-16. Broader Impacts We have developed a coherent, integrated, interdisciplinary research and training program that includes field observations, experimental manipulations at sea and in the laboratory, and diverse modeling advances. We have built a collaborative, interactive group of scientists, students, engineers, technical staff, and outreach personnel. We have trained a large group of graduate students and sizable number of postdoctoral investigators and undergraduate students in collaborative, seagoing science and prepared them for careers in science. Many technical personnel have developed refined skills and state-of-the-art competence in their respective disciplines. Our laboratory facilities (and seagoing instrument capacity) now include excellent resources for biological, chemical, and physical oceanographic studies. We have built a state-of-the-art Information Management resource called DataZoo that effectively serves data to diverse users. Our data are posted for widespread use by the scientific community and have been downloaded by people in 29 countries around the world. We have a highly effective team that collaborates to communicate our advances in the ocean sciences outside the research laboratory. We communicate directly with school groups, the general public, and federal, state, and local representatives regarding the importance of the California Current Pelagic Ecosystem from diverse perspectives. We are stimulating diverse age groups ranging from school children through undergraduate students to consider the impact of ocean ecosystems on their lives and on public policy. Our autonomous real-time data, combined with model reanalyses, assist with the management of marine resources (e.g., coastal finfish and invertebrate fisheries) both by helping to (a) understand causes for past environmental conditions that have influenced marine resources and (b) provide near real-time information for updating management decisions as environmental conditions change. We have illustrated the power of integration of empirical field measurements from diverse sources (shipboard, autonomous instruments, satellite remote sensing) with at-sea experimental manipulations and data-assimilating models. This integration provides a quantitative framework for sensitivity analyses and for developing the foundation for forecasting future states of this major ocean ecosystem. Last Modified: 11/06/2017 Submitted by: Mark D Ohman