Cooperative Institute for Research in Environmental SciencesCooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder
Sea level and climate variability in the Pacific Ocean

Fog rolls in to Cannon Beach on the Oregon Coast.
- CIRES
May 30, 2025
Sea level and climate variability in the Pacific Ocean
Work led by former CIRES Visiting Fellow Chris Little uncovered 3 distinct spatial patterns in Pacific Ocean tide gauge sea level records:
- A spatially uniform rise, smaller than that found in other ocean basins, related to long-term changes in greenhouse gases;
- A non-linear pattern, potentially linked to aerosols, which are tiny particles — like dust or smoke — suspended in the atmosphere; and
- A cyclical pattern related to the Interdecadal Pacific Oscillation, a long-term (15 – 30 year) cycle in ocean surface temperatures and surface winds in the Pacific Ocean.
The team, which includes CIRES Fellows Kris Karnauskas and Steve Nerem, found that 30-year satellite-derived regional sea level trends are dominated by the non-linear aerosol pattern. The results suggest that these records might not accurately represent longer-term historical patterns or changes in the future.
Read the paper in Science Advances.