Contemporary Sea Level Budget

Understanding contemporary sea level change is crucial for coastal adaptation and climate impact assessment. Global mean sea level has been rising at an accelerating rate, with significant regional variations that affect billions of people living in coastal areas worldwide.

This research analyzes contemporary sea level budget components including thermal expansion, ice sheet melting, glacier mass loss, and regional variations. We investigate the mechanisms behind global and regional sea level changes and their implications for coastal communities and climate adaptation strategies.

Our work contributes to closing the sea level budget by quantifying individual contributions and understanding the physical processes driving observed sea level changes across different spatial and temporal scales.

Schematic showing the major components of contemporary sea level change including thermal expansion, ice mass loss, and regional patterns.

Sea Level Budget Components

Thermal Expansion

  • Ocean heat content changes
  • Thermosteric sea level rise
  • Regional thermal expansion patterns
  • Deep ocean warming contributions

Mass Contributions

  • Ice sheet mass balance (Greenland, Antarctica)
  • Glacier and ice cap melting
  • Terrestrial water storage changes
  • Atmospheric water vapor changes

Research Methods

  • Satellite Altimetry: Analysis of TOPEX/Poseidon, Jason series, and Sentinel-6 data
  • Gravimetry: GRACE and GRACE-FO satellite gravity measurements for mass changes
  • Ocean Observations: Argo float data for thermal expansion calculations
  • Ice Sheet Monitoring: Integration of satellite and in-situ ice mass balance data
  • Statistical Analysis: Trend analysis, uncertainty quantification, and attribution studies

Key Findings

  • Acceleration in global mean sea level rise from ~1.5 mm/yr (1900-1990) to ~3.3 mm/yr (1993-present)
  • Thermal expansion contributes approximately 40% of contemporary sea level rise
  • Ice sheet mass loss has become the dominant contributor since 2000s
  • Significant regional variations with some areas experiencing 3-4 times the global average
  • Improved closure of the sea level budget within observational uncertainties

Regional Sea Level Patterns

Pacific Ocean

Strong regional variations related to ENSO, PDO, and trade wind changes. Western Pacific shows enhanced sea level rise.

Atlantic Ocean

AMOC-related patterns with enhanced rise along the U.S. East Coast and reduced rise in the North Atlantic.

Indian Ocean

Monsoon-related variability and enhanced warming in the western tropical Indian Ocean.

Climate and Societal Implications

  • Coastal Vulnerability: Enhanced understanding of regional sea level patterns for coastal risk assessment
  • Climate Projections: Improved constraints for future sea level projections and uncertainty quantification
  • Adaptation Planning: Regional sea level information for infrastructure planning and coastal management
  • Policy Support: Scientific evidence for climate policy and international climate negotiations

Collaboration

Duration: 2020 - Present

International Partnerships: NASA JPL, NOAA, University of Colorado, CSIRO Australia

Working Groups: WCRP Sea Level Budget Assessment, IPCC AR6 Sea Level Chapter

Funding: National Key R&D Program, NASA Sea Level Change Team, International collaboration grants