Three MIT affiliates—Anthea Coster of the Haystack Observatory, Carolyn Ruppel (’86) of the MIT Energy Initiative, and César Terrer of the Department of Civil and Environmental Engineering—have been elected 2026 fellows of the American Geophysical Union (AGU). The AGU also honored eight additional MIT alumni as fellows: Claudia Benitez‑Nelson, Robert Howarth, Douglas J. Jerolmack, Tamara Shapiro Ledley, Galen A. McKinley, Mark David Schmitz, Frederik J. Simons, and Dawn Y. Sumner. With about 60,000 members worldwide, AGU selects less than 0.1% of its membership each year to recognize exceptional breakthroughs, discoveries, or innovations in Earth and space science.
Anthea Coster is an MIT principal research scientist and emerita assistant director of Haystack Observatory. She joined MIT in 1984, originally at Lincoln Laboratory, and focuses on atmospheric physics across the ionosphere, magnetosphere, and thermosphere, as well as space‑weather coupling. Her work on global navigation satellite system (GNSS) applications has produced several breakthroughs, including the first GNSS observations of storm‑enhanced density over the continental United States, earning her the International Radio Science Union’s Appleton Prize. She co‑founded an annual GNSS workshop series (since 2009) with Boston College and the ICTP, training 40‑50 participants from developing nations each year, and has participated in UN‑sponsored International Space Weather Initiative outreach, bringing space physics to South America, Africa, tribal Alaska, and advocating for women and underserved groups.
Carolyn Ruppel serves as deputy director of science and technology at the MIT Energy Initiative and is a life member of AGU. She is an expert on gas hydrates—ice‑like structures that trap methane, accounting for roughly 15% of the planet’s methane budget. Before joining MITEI in 2025, she worked at Woods Hole Oceanographic Institution, Georgia Tech, and the USGS Woods Hole coastal and marine research center. Starting in 2010, she led the USGS Gas Hydrates Project, investigating the resource potential of shallow, widespread deposits and the feedbacks between warming climate, hydrate breakdown, and methane release. Her contributions include debunking catastrophic hydrate‑release scenarios, discovering over 700 seafloor methane seeps along the U.S. Atlantic margin, and advancing research on continental rifting, subsea permafrost, hydrate reservoir dynamics, and marine heat flow acoustics.
César Terrer holds the TianFu Group Career Development Professorship and is an associate professor of civil and environmental engineering. He studies the land carbon sink—about 30% of annual CO₂ emissions absorbed by plants and soils—and its future stability. By replacing model assumptions with global observations (CO₂ experiments, soil inventories, forest plots, satellites), his group showed that soil nutrients limit additional carbon uptake to roughly one‑third of model estimates, that plant and soil carbon trade off rather than accumulate together, and that animals influence the carbon cycle, with tropical forests lacking seed dispersers regrowing less than a quarter as much carbon as intact forests. All of his first‑author papers are cited in the IPCC Sixth Assessment Report; NASA selected him to co‑lead the modeling and data synthesis work for PANGEA, and companies such as Apple, Cargill, PepsiCo, and Inditex have sought his advice on natural climate solutions.
The AGU Fellow awards will be presented at the AGU Fall Meeting in San Francisco this December. Review