PIPages
Labs

James Moum

Oregon State University, OR·Earth & Environmental Science

Along the equator in the Pacific and Atlantic oceans lie 'cold tongues', bands of unusually cool surface water that take up large amounts of heat. How that heat moves downward depends on turbulent mixing, small-scale stirring of the ocean that is hard to measure.

Fields

Earth & Environmental Science

Physics

Topics

physical oceanography

ocean turbulence

turbulent mixing

Grants
2 known grants, through Aug 2027

What they work on

  1. 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.
  2. Track the fate of internal waves at critical layers below tropical instability waves and how this sets turbulent mixing over the seasonal cycle, using three moorings deployed for a year near the 140°W TAO mooring.
  3. Record four years of temperature-variance dissipation with ChiPods, lab-built turbulence sensors, on moorings at two Atlantic and one Pacific equatorial site to resolve long-term mixing in the cold tongues.
  4. Quantify how much heat turbulence carries into the deeper ocean, whether mixing shaped Pacific cold tongue heat uptake during the warming hiatus, and related biases in high-resolution ocean models.

More about the research

This mixing shapes climate patterns such as the El Niño Southern Oscillation (ENSO). Both projects measure the mixing directly at sea and relate it to tropical instability waves (TIWs), large westward-moving waves that ripple along the equator.

Why it matters

Turbulent mixing controls how much heat the tropical ocean absorbs and stores below the surface, which affects ENSO and the role of the tropics in climate. Long, direct mixing records and a clearer picture of how tropical instability waves drive mixing could improve ENSO predictability. They could also help correct mixing-related biases in the ocean models used to understand climate.

Known grants

From NIH and NSF research grants. Labs often have other funding we can't see.

Collaborative Research: Evaluating mechanisms for enhanced mixing below tropical instability waves

NSF · Sep 2021 – Aug 2027

Collaborative Research: Cold Tongue Mixing

NSF · Apr 2021 – Mar 2027

Closest labs

Samantha Stevenson

University of California-Santa Barbara, CA·Earth & Environmental Science·Early-career

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.

Jean Lynch-Stieglitz

Georgia Institute of Technology, GA·Earth & Environmental Science

Test how changes in tropical winds alter thermocline depth across the Indo-Pacific by running sensitivity experiments in a high-resolution ocean model.

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.

The school

Oregon State University: 29 labs on PI Pages, $372M a year on research, 238 research doctorates a year.

More about Oregon State University

Reach out

A start for your email. Fill in the brackets.