About

Robert Sherrell is an Associate Professor at Rutgers University in the Department of Earth and Planetary Sciences. He holds a B.A. from Oberlin College and a Ph.D. from the Massachusetts Institute of Technology in conjunction with the Woods Hole Oceanographic Institution. His research focuses on the geochemistry of marine and fresh waters, as well as paleochemical records in ice cores. Sherrell's work involves studying the chemical composition and processes of Earth's water systems to better understand environmental and planetary changes.

Research topics

• Geology
• Environmental science
• Oceanography
• Environmental chemistry
• Chemistry
• Meteorology
• Ecology
• Biology
• Atmospheric sciences
• Climatology
• Geochemistry
• Geomorphology
• Geography

Selected publications

• Iron supply to the Amundsen Sea, Antarctica is dominated by circumpolar deepwater and continental subglacial sources

  Communications Earth & Environment · 2026-02-26

  articleOpen accessSenior author

  Glacial melting in West Antarctica has intensified with the increased intrusion of warm ocean water beneath ice shelves, but the processes controlling the export of meltwater-associated micronutrient iron (Fe) to Southern Ocean surface waters remain unclear. Here, we report Fe concentrations and dissolved Fe (dFe) isotope ratios in the inflowing deepwater layer that drives melting of the Dotson Ice Shelf and in the meltwater-enriched outflow to determine meltwater-derived dFe. Isotopic mass balance points to an anoxic Fe-reducing region of the upstream subglacial hydrologic system as the dominant source of meltwater dFe, rather than ice shelf melt itself. Remarkably, total meltwater contributes only ~10% of outflowing dFe, with the majority contributed by inflowing deep water (62%), augmented by inputs from shelf sediments (28%). Outflowing suspended particulate Fe exceeds inflow by 46%, at 100 times the dFe concentration, with 25% in reactive phases. Predictive models of future ecosystem effects should consider that the primary role of ice shelf melting is to provide buoyancy that transports Fe from deep sources to the Fe-limited surface ocean, stimulating phytoplankton growth. Meltwater generated within the Dotson Ice Shelf cavity supplies little dissolved iron. Most meltwater-derived iron found in water flowing out of the cavity comes from subglacial discharge, based on iron concentrations and dissolved iron isotope ratios.

  PublisherOA PDFDOI

• Scientific sampling event log from the US GEOTRACES GP17-ANT cruise in the Amundsen Sea on RVIB Nathaniel B. Palmer (NBP2401) from November 2023 to January 2024

  Open MIND · 2026-03-06

  datasetSenior author

  This dataset is the scientific sampling event log from the US GEOTRACES GP17-ANT cruise on RVIB Nathaniel B. Palmer (NBP2401). The U.S. GEOTRACES GP17-ANT expedition departed Punta Arenas, Chile on November 29th, 2023 and arrived in Lyttelton, New Zealand on January 28th, 2024. The cruise took place in the Amundsen Sea with a team of 35 scientists led by Peter Sedwick (Old Dominion University), Phoebe Lam (University of California, Santa Cruz), and Robert Sherrell (Rutgers University). GP17 was planned as a two-leg expedition, with its first leg (GP17-OCE) as a southward extension of the 2018 GP15 Alaska-Tahiti expedition and this second leg (GP17-ANT) into coastal and shelf waters of Antarctica's Amundsen Sea.

  DOI

• Iron supply to the Amundsen Sea, Antarctica is dominated by circumpolar deepwater and continental subglacial sources

  Zenodo (CERN European Organization for Nuclear Research) · 2026-01-14 · 1 citations

  datasetOpen accessSenior author

  The geochemical data provided here is used in the manuscript entitled "Iron supply to the Amundsen Sea, Antarctica is dominated by circumpolar deepwater and continental subglacial sources," which is accepted for publication in the Nature portfolio journal Communications Earth and Environment. This dataset has been archived for open access.

  PublisherDOI

• Iron supply to the Amundsen Sea, Antarctica is dominated by circumpolar deepwater and continental subglacial sources

  Open MIND · 2026-01-14

  datasetSenior author

  The geochemical data provided here is used in the manuscript entitled "Iron supply to the Amundsen Sea, Antarctica is dominated by circumpolar deepwater and continental subglacial sources," which is accepted for publication in the Nature portfolio journal Communications Earth and Environment. This dataset has been archived for open access.

  DOI

• Benthic sediments are a primary source of dissolved trace metals to Antarctic waters: Case studies from various Antarctic continental shelves

  2025-01-01

  articleSenior author
  PublisherDOI

• Antarctic glaciers export carbon-stabilised iron(II)-rich particles to the surface Southern Ocean

  Nature Communications · 2025-05-30 · 9 citations

  articleOpen access

  Iron is an essential micronutrient for phytoplankton and plays an integral role in the marine carbon cycle. The supply and bioavailability of iron are therefore important modulators of climate over glacial-interglacial cycles. Inputs of iron from the Antarctic continental shelf alleviate iron limitation in the Southern Ocean, driving hotspots of productivity. Glacial meltwater fluxes can deliver high volumes of particulate iron. Here, we show that glacier meltwater provides particles rich in iron(II) to the Antarctic shelf surface ocean. Particulate iron(II) is understood to be more bioavailable to phytoplankton, but less stable in oxic seawater, than iron(III). Using x-ray microscopy, we demonstrate co-occurrence of iron and organic carbon-rich phases, suggesting that organic carbon retards the oxidation of potentially-bioavailable iron(II) in oxic seawater. Accelerating meltwater fluxes may provide an increasingly important source of bioavailable iron(II)-rich particles to the Antarctic surface ocean, with implications for the Southern Ocean carbon pump and ecosystem productivity.

  PublisherOA PDFDOI

• Cracking the code: iron isotopes as source tracers in the Antarctic

  2025-01-01

  articleSenior author
  PublisherDOI

• Supply, cycling and export of trace metal micronutrients from Greenland fjords traced by Cu and Zn isotope ratios

  2025-01-01

  article
  PublisherDOI

• Tracing Antarctic snow's chemical and biological properties in the air-polar ocean exchange

  2025-01-01

  article
  PublisherDOI

• Isotopic Tracing of Trace Metal Micronutrients in Polar Fjords

  2024-01-01

  articleOpen accessSenior author
  PublisherOA PDFDOI

Recent grants

• A Coral Skeleton P/Ca Proxy for Surface Ocean Phosphate: Testing and calibration

  NSF · $431k · 2008–2013

• P2C2: Rapid Climate Variations--A Speleothem-based High-resolution Record of Rainfall in the Equatorial South Pacific over the Last 83,000 Years

  NSF · $528k · 2011–2015

• Collaborative Research: The Nitrifying of Lake Superior and Its Intersections with the P and Fe Cycles

  NSF · $194k · 2004–2007

• Collaborative Research: Investigating the Role of Mesoscale Processes and Ice Dynamics in Carbon and Iron Fluxes in a Changing Amundsen Sea (INSPIRE)

  NSF · $50k · 2015–2018

• Natural Fe Fertilization and Bioactive Metal Dynamics on the Western Antarctic Peninsula Shelf

  NSF · $504k · 2012–2017

Frequent coauthors

• Jessica N. Fitzsimmons

  Texas A&M University

  38 shared

• M. Field

  31 shared

• Sharon Stammerjohn

  University of Colorado Boulder

  25 shared

• Carles Pelejero

  Institut Català de Ciències del Clima

  19 shared

• Patricia L. Yager

  18 shared

• M. LaVigne

  Bowdoin College

  18 shared

• Reinhard Kozdon

  Columbia University

  15 shared

• Michael P. Meredith

  British Antarctic Survey

  14 shared

Labs

• Earth and Planetary Science Isotope Laboratory (EPSIL)PI

  The Earth and Planetary Science Isotope Laboratory (EPSIL) is a research facility at Rutgers University specializing in isotope geochemistry and related fields.