INTRODUCTION TO THE SPECIAL ISSUE. Paleoceanography: Lessons for a Changing World
By Amelia Shevenell, Peggy Delaney, Katrin Meissner, Laurie Menviel, and Alan C. Mix

Time Machine Biology: Cross-Timescale Integration of Ecology, Evolution, and Oceanography
By Moriaki Yasuhara, Huai-Hsuan May Huang, Pincelli Hull, Marina C. Rillo, Fabien L. Condamine, Derek P. Tittensor, Michal Kučera, Mark J. Costello, Seth Finnegan, Aaron O’Dea, Yuanyuan Hong, Timothy C. Bonebrake, N. Ryan McKenzie, Hideyuki Doi, Chih-Lin Wei, Yasuhiro Kubota, and Erin E. Saupe

SIDEBAR. On Quantifying Stratigraphic, Chronologic, and Paleo Flux Uncertainties in Paleoceanography
By Alan C. Mix

Ancient Sea Level as Key to the Future
By Kenneth G. Miller, W. John Schmelz, James V. Browning, Robert E. Kopp, Gregory S. Mountain, and James D. Wright

SIDEBAR. Boron Isotopes Provide Insights into Biomineralization, Seawater pH, and Ancient Atmospheric CO₂
By Jessica G.M. Crumpton-Banks and James W.B. Rae

Linkages Between Dynamic Phytoplankton C:N:P and the Ocean Carbon Cycle Under Climate Change
By Katsumi Matsumoto, Tatsuro Tanioka, and Rosalind Rickaby

SIDEBAR. Direct Measures of the Vigor of Ocean Circulation via Particle Grain Size
By Nick McCave

Regional Character of the “Global Monsoon”: Paleoclimate Insights from Northwest Indian Lacustrine Sediments
By Yama Dixit

SIDEBAR. Illuminating the Past to See the Future of Western Boundary Currents: Micropaleontological Investigations of the Kuroshio Current Extension
By Adriane R. Lam, R. Mark Leckie, and Molly O. Patterson

Extending the Instrumental Record of Ocean-Atmosphere Variability into the Last Interglacial Using Tropical Corals
By Thomas Felis

Reconstruction of Ocean Circulation Based on Neodymium Isotopic Composition: Potential Limitations and Application to the Mid-Pleistocene Transition
By Kazuyo Tachikawa, William Rapuc, Quentin Dubois-Dauphin, Abel Guihou, and Charlotte Skonieczny

SIDEBAR. Amundsen Sea Coastal Ice Rises: Future Sites for Marine-Focused Ice Core Records
By Peter Neff

The Antarctic Ice Sheet: A Paleoclimate Modeling Perspective
By Edward G.W. Gasson and Benjamin A. Keisling

SIDEBAR. The Mid-Pleistocene Enigma 
By Heather L. Ford and Thomas B. Chalk

Archaeal Membrane Lipid-Based Paleothermometry for Applications in Polar Oceans
By Susanne Fietz, Sze Ling Ho, and Carme Huguet

SIDEBAR. Diatoms as Sea Ice Proxies
By Amy Leventer

The Potential of Sedimentary Ancient DNA to Reconstruct Past Ocean Ecosystems
By Linda H. Armbrecht

SIDEBAR. A Memory of Ice: The Antarctic Voyage of the Glomar Challenger
By Peter N. Webb and Peter J. Barrett

The Origins of Oceanography in France: The Scientific Expeditions of Travailleur and Talisman (1880–1883)
By John R. Dolan

How Do Advisor Assessments of Diverse Undergraduate Researchers Compare with the Students’ Self-Assessments? And What Does This Imply for How We Train and Assess Students?
By Barbara C. Bruno, Cherryle Heu, and Grady Weyenberg

Deep Ocean Passive Acoustic Technologies for Exploration of Ocean and Surface Sea Worlds in the Outer Solar System
By Robert Dziak, Don Banfield, Ralph Lorenz, Haruyoshi Matsumoto, Holger Klinck, Richard Dissly, Christian Meinig, and Brian Kahn

QUARTERDECK • Oceanography During the COVID-19 Pandemic
By Ellen S. Kappel

FROM THE PRESIDENT • Ocean Science During the Corona Virus Pandemic: Challenges and Opportunities
By Martin Visbeck

COMMENTARY • Strategies for Running a Successful Virtual Career Panel
By Janine Barr, Christine Bean, and Janice McDonnell

RIPPLE MARKS • Good News Fish Story
By Cheryl Lyn Dybas

DIY OCEANOGRAPHY • The Pressure of In Situ Gases Instrument (PIGI) for Autonomous Shipboard Measurement of Dissolved O₂ and N₂ in Surface Ocean Waters
By Robert W. Izett and Philippe Tortell

THE OCEANOGRAPHY CLASSROOM • Project EDDIE: Using Real Data in Science Classrooms
By Dax Soule

CAREER PROFILES • Options and Insights
Career Profiles—Options and Insights. 2020. Oceanography 33(2):165–167.

TRIBUTE • A Tribute to Thomas B. Sanford (1940–2020)
By Eric Kunze and Ren-Chieh Lien

Amelia Shevenell, University of South Florida
Peggy Delaney, UC Santa Cruz
Katrin Meissner, University of New South Wales
Laurie Menviel, University of New South Wales
Alan Mix, Oregon State University

Production of this issue of Oceanography was supported by National Science Foundation grant OCE-1912795.