NSF Award
2317774
The West Antarctic Peninsula is one of the fastest warming regions in Antarctica, impacting carbon fluxes from the atmosphere to the ocean through effects on phytoplankton blooms, the microscopic marine plants that form the base of the food web. This project investigates changes in the seasonal timing, amount, and type of phytoplankton as the West Antarctic Peninsula warms and experiences sea ice loss. This study of a critically important ecosystem’s carbon cycle and shifting seasonal timing of events is relevant to all polar systems in the face of global climate warming. The proposed research will broaden our understanding of the impact of climate change on the seasonal timing of primary production and carbon uptake in a region experiencing the most rapid rate of sea ice loss in the Antarctic. The Southern Ocean is a massive regulator of the global carbon budget, but many unknowns remain about the role of phytoplankton. This work will look at two features of how phytoplankton influence carbon uptake that are often overlooked: phytoplankton community composition and phenology (i.e., the timing of seasonal events).<br/><br/>The goal of the proposed work is to assess how physical and biological factors affect the seasonal timing, magnitude, and long-term trends of carbon flux from the atmosphere to the ocean. Researchers will incorporate data collected in West Antarctica with numerical modeling to test possible reasons why things are changing, and to test specific variables at the base of the food web. Observations will be used to evaluate long-term change, and models will be used to investigate likely causes for observed shifts, such as changes in sea ice, wind, ocean physics, cloudiness, and phytoplankton community composition. The objectives of the proposed work are to (1) analyze phenology shifts, (2) investigate phytoplankton community composition using pigment and flow-through imaging data from the Palmer Long-Term Ecological Research program, (3) evaluate possible reasons for shifts in phenology using modeling case studies, and (4) compare the relative impacts of biological factors versus physical factors on carbon flux and phenology shifts using modeling experiments. Outreach and education activities include blog and video development for the Palmer Long-Term Ecological Research (LTER) program, mentoring of undergraduate college students, and K-12 lesson plan development in alignment with Polar Literacy Principles.<br/><br/>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.
