Welcome to the Oceanography special issue on Twenty Years of GEOTRACES. This issue is in progress and articles will be posted as they are available. Please check back for new articles.

FROM THE GUEST EDITORS • Introduction to the Special Issue
By Tim M. Conway, Jessica N. Fitzsimmons, Rob Middag , Taryn L. Noble, and Hélène Planquette

PERSPECTIVE • GEOTRACES Reflections
By Robert F. Anderson

PERSPECTIVE • A Young Scientist’s Perspective on GEOTRACES
By Dylan J. Halbeisen

PERSPECTIVE • The Value of Going To Sea on Big Ships and the Advantage of Multiple Tracers for GEOTRACES Style Programs
By Catherine Jeandel

PERSPECTIVE • Intercalibration: A Cornerstone of the Success of the GEOTRACES Program
By Ana Aguilar-Islas, Hélène Planquette, Maeve C. Lohan, Walter Geibert, and Gregory Cutter

The GEOTRACES Intermediate Data Products: Rich Resources for Research, Education, and Outreach
By Reiner Schlitzer and Sebastian Mieruch-Schnülle

SPOTLIGHT • Three-Minute Videos to Learn About Marine Geochemistry
By Elena Masferrer Dodas, Catherine Jeandel, and Adrian Artis

The Southern Ocean Hub for Nutrients, Micronutrients, and Their Isotopes in the Global Ocean
By Gregory F. de Souza and Adele K. Morrison

Shelf-Basin Connectivity Drives Dissolved Fe and Mn Distributions in the Western Arctic Ocean: A Synoptic View into Polar Trace Metal Cycling
By Laramie Jensen and Manuel Colombo

On the Variability of Equatorial Pacific Nitrate and Iron Utilization
By Patrick A. Rafter

Advances in Understanding the Marine Nitrogen Cycle in the GEOTRACES Era
By Karen L. Casciotti, Tanya A. Marshall, Sarah E. Fawcett, and Angela N. Knapp

PERSPECTIVE • GEOTRACES: Fifteen Years of Progress in Marine Aerosol Research
By Clifton S. Buck, Susanne Fietz, Douglas S. Hamilton, Tung-Yuan Ho, Morgane M.G. Perron, and Rachel U. Shelley

An Ocean of Particles Characterization of Particulate Trace Elements by the GEOTRACES Program
By Benjamin S. Twining

PERSPECTIVE • Timekeepers for Trace Elements in the Global Ocean: The Thorium Stopwatches
By Christopher T. Hayes

DIY OCEANOGRAPHY • Design Update to “The Pressure of In-Situ Gases Instrument (PIGI) for Autonomous Shipboard Measurement of Dissolved O₂ and N₂ in Surface Ocean Waters”
By Benjamin Lowin, Robert Izett, Edward Taylor, Charles Robertson, and Sara Rivero-Calle

TRIBUTE • A Tribute to Richard W. Eppley
By Paul G. Falkowski, ed.

CAREER PROFILES • OPTIONS AND INSIGHTS: Trisha Bergmann
By Trisha Bergmann

CAREER PROFILES • OPTIONS AND INSIGHTS: Meredith Jennings
By Meredith Jennings

Tim Conway, University of South Florida
Jessica Fitzsimmons, Texas A&M University
Rob Middag, Royal NIOZ
Taryn Noble, University of Tasmania
Hélène Planquette, University of Brest

Support for production of this special issue was provided by the US National Science Foundation, award OCE-2219888 to Robert Anderson.