Oceans play an important role in the Earth’s carbon cycle. Within the oceans, the intensity of carbon fixation and export is strongly dependent on the concentration and composition of various water constituents including phytoplankton. Yet, the ocean color satellites have so far been largely used to derive the total phytoplankton concentration regardless of its composition. Different phytoplankton groups have however disparate impacts on ocean ecology, nutrient cycling, and the carbon cycle.
Therefore, total chlorophyll as currently measured by ocean color is no longer sufficient to describe the full complexity of the ocean carbon cycle. As a direct result of this gap in knowledge, satellite and field sampling missions, such as the NASA Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite mission and the EXport Processes in the Ocean from Remote Sensing (EXPORTS) field campaign, have been developed to improve our understanding of these processes and how likely they are to respond to climate variability and change. Earth System Models on the other hand have become more complex and now include a variety of mechanisms and variables that are not always measured directly from satellites or in the field. The use of models combined with data assimilation allows for the integration of existing satellite data and provide global continuous data in the oceans, land and in the atmosphere.
Dr. Cecile Rousseaux will show how the NASA Ocean Biogeochemical Model (NOBM) has been used in various projects to prepare for field and satellite missions and improve our understanding of how to best use these satellite and field campaign data, and the potential limitations of the field sampling design and/or satellite mission.