Samantha Stevenson
University of California-Santa Barbara, CA·Earth & Environmental Science·Early-career
El Niño and La Niña are warm and cool swings in the tropical Pacific Ocean that drive floods, droughts and storms worldwide. Together they form a cycle called the El Niño/Southern Oscillation (ENSO).
- Fields
Earth & Environmental Science
- Topics
El Niño
La Niña
paleoclimate
- Grants
- 3 known grants, through Jul 2028
What they work on
- Build an oxygen isotope "isoscape" of tropical Pacific seawater and rainfall during El Niño and La Niña, using samples from long-running collection sites and a new high-resolution, isotope-enabled ocean reanalysis.
- Separate the effects of temperature and seawater δ18O on coral δ18O, and test whether coral records show stronger ENSO-related rainfall swings in recent decades.
- Determine how future ENSO changes depend on the average climate state and on small-scale ocean eddies, using large CMIP-class model ensembles and new diagnostics for Tropical Instability Waves.
- Create the first coupled perturbed-physics ensembles, in which model physics settings are deliberately varied, along with new emergent constraints that use observations to narrow the spread of ENSO projections.
- Reconstruct past sea surface temperatures in the Tropical North Atlantic and Western Indian Ocean from the chemistry of centuries-old coral cores, to trace how the tropical oceans have interacted.
- Compare coral-based records of how the three tropical oceans interact with iCESM Last Millennium Ensemble runs, including single-forcing and targeted sensitivity experiments.
More about the research
Scientists still do not know how ENSO will respond to climate change, and records from thermometers are too short to show how it has varied over past centuries. This research combines climate models with natural archives, especially the chemistry of coral skeletons, which record past ocean conditions. The goal is to understand how ENSO and the connections among the tropical oceans have changed in the past and may change in the future.
Why it matters
ENSO drives droughts, floods and tropical storms that affect people around the world. Better-constrained projections of ENSO, and a clearer reading of coral climate records, could help governments, farmers and coastal communities plan for future extremes. Knowing how the tropical oceans interact could also improve climate model predictions for the tropics and beyond.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Collaborative Research: Stable isotope constraints on the hydrologic expression of the El Nino/Southern Oscillation in the tropical Pacific Ocean
NSF · Aug 2025 – Jul 2028
CAREER: Narrowing the Spread: Process Understanding for Reduced Uncertainty in Future El Nino/Southern Oscillation Projections
NSF · Jul 2022 – Jun 2027
Collaborative Research: Reconstructing Climate Linkages Across the Tropical Oceans Over the Last Millennium
NSF · Jun 2022 – May 2027
Closest labs
Jessica Conroy
University of Illinois Urbana-Champaign, IL·Earth & Environmental Science
Map an oxygen isotope "isoscape" of the modern tropical Pacific from long-running seawater and precipitation collection sites, showing how seawater and rainfall isotope values shift between El Niño and La Niña phases.
Diana Thatcher
Iowa State University, IA·Earth & Environmental Science
Reconstruct annually resolved, millennial-length northeast Pacific sea-surface temperatures from growth increments in shells of the Pacific geoduck, a long-lived marine clam.
James Moum
Oregon State University, OR·Earth & Environmental Science
Test whether tropical instability waves in the equatorial Pacific radiate internal waves downward and reshape the internal wave field, using moorings, a fastCTD, the Epsilometer turbulence profiler and WireWalker drifting profilers.
The school
University of California-Santa Barbara: 17 labs on PI Pages, $303M a year on research, 403 research doctorates a year.
Reach out
A start for your email. Fill in the brackets.