Why in News?
The Surface Water and Ocean Topography (SWOT) satellite is in the news because it has recently delivered groundbreaking results in tsunami science and ocean floor mapping. In late March 2026, researchers revealed that SWOT data captured "hidden" signals from the 2025 Kamchatka earthquake tsunami, offering a rare multidimensional view that could significantly improve early warning systems.
Key Information
- Mission Overview: A joint project between NASA (USA) and CNES (France), with contributions from the UK and Canadian space agencies.
- Primary Objective: To conduct the first global survey of Earth's surface water, measuring the height of oceans, rivers, lakes, and reservoirs.
- Launch Details: Launched on December 16, 2022, via a SpaceX Falcon 9 rocket from Vandenberg Space Force Base.
Key Technology
- KaRIn (Ka-band Radar Interferometer): The main instrument that uses radar pulses to measure water surface height with centimetre-level accuracy.
- Wide-Swath Altimetry: Unlike previous satellites that measured water in narrow lines, SWOT scans a 120-km wide strip, covering 90% of the globe every 21 days.
Monitoring Capability
- Rivers: Observes nearly all rivers wider than 100 metres (330 feet).
- Lakes: Monitors over a million lakes larger than 15 acres.
Climate Significance
- It tracks small-scale ocean currents and eddies (less than 100 km across) that are responsible for absorbing over 90% of the excess heat trapped in the atmosphere by greenhouse gases.
- Societal Impact: Provides vital data for flood and drought forecasting, coastal resource management, and improving the accuracy of climate change models.
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