The MESO-SCOPE (Microbial Ecology of the Surface Ocean - Simons Collaboration on Ocean Processes and Ecology) expedition collected oceanographic observations in the region north of the Hawaiian Islands with the aim of identifying the impact of mesoscale eddies on the ecosystem of the North Pacific Subtropical Gyre. The expedition targeted a mesoscale dipole north of the island of Oahu (eddies C1 and A1 in the figure) to characterize: 1) the horizontal variability in biogeochemical and ecological properties across the two eddies; and 2) Lagrangian temporal dynamics at the two eddy centers, with a particular focus on diel processes.