An operational overview of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) Northeast Pacific field deployment
Authors: Siegel David A. , Cetinić Ivona , Graff Jason R. , Lee Craig M. , Nelson Norman , Perry Mary Jane , Ramos Inia Soto , Steinberg Deborah K. , Buesseler Ken , Hamme Roberta , Fassbender Andrea J. , Nicholson David , Omand Melissa M. , Robert Marie , Thompson Andrew , Amaral Vinicius , Behrenfeld Michael , Benitez-Nelson Claudia , Bisson Kelsey , Boss Emmanuel , Boyd Philip W. , Brzezinski Mark , Buck Kristen , Burd Adrian , Burns Shannon , Caprara Salvatore , Carlson Craig , Cassar Nicolas , Close Hilary , D’Asaro Eric , Durkin Colleen , Erickson Zachary , Estapa Margaret L. , Fields Erik , Fox James , Freeman Scott , Gifford Scott , Gong Weida , Gray Deric , Guidi Lionel , Haëntjens Nils , Halsey Kim , Huot Yannick , Hansell Dennis , Jenkins Bethany , Karp-Boss Lee , Kramer Sasha , Lam Phoebe , Lee Jong-Mi , Maas Amy , Marchal Olivier , Marchetti Adrian , McDonnell Andrew , McNair Heather , Menden-Deuer Susanne , Morison Francoise , Niebergall Alexandria K. , Passow Uta , Popp Brian , Potvin Geneviève , Resplandy Laure , Roca-Martí Montserrat , Roesler Collin , Rynearson Tatiana , Traylor Shawnee , Santoro Alyson , Seraphin Kanesa Duncan , Sosik Heidi M. , Stamieszkin Karen , Stephens Brandon , Tang Weiyi , Van Mooy Benjamin , Xiong Yuanheng , Zhang Xiaodong 
Published: July 2021

The goal of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) field campaign is to develop a predictive understanding of the export, fate, and carbon cycle impacts of global ocean net primary production. To accomplish this goal, observations of export flux pathways, plankton community composition, food web processes, and optical, physical, and biogeochemical (BGC) properties are needed over a range of ecosystem states. Here we introduce the first EXPORTS field deployment to Ocean Station Papa in the Northeast Pacific Ocean during summer of 2018, providing context for other papers in this special collection. The experiment was conducted with two ships: a Process Ship, focused on ecological rates, BGC fluxes, temporal changes in food web, and BGC and optical properties, that followed an instrumented Lagrangian float; and a Survey Ship that sampled BGC and optical properties in spatial patterns around the Process Ship. An array of autonomous underwater assets provided measurements over a range of spatial and temporal scales, and partnering programs and remote sensing observations provided additional observational context. The oceanographic setting was typical of late-summer conditions at Ocean Station Papa: a shallow mixed layer, strong vertical and weak horizontal gradients in hydrographic properties, sluggish sub-inertial currents, elevated macronutrient concentrations and low phytoplankton abundances. Although nutrient concentrations were consistent with previous observations, mixed layer chlorophyll was lower than typically observed, resulting in a deeper euphotic zone. Analyses of surface layer temperature and salinity found three distinct surface water types, allowing for diagnosis of whether observed changes were spatial or temporal. The 2018 EXPORTS field deployment is among the most comprehensive biological pump studies ever conducted. A second deployment to the North Atlantic Ocean occurred in spring 2021, which will be followed by focused work on data synthesis and modeling using the entire EXPORTS data set.