NASA’s Surface Water and Ocean Topography (SWOT) satellite has achieved a groundbreaking feat by mapping almost all of Earth’s water, creating the first comprehensive map of the planet’s water resources. These fresh global maps of sea levels were generated using data obtained from the SWOT satellite, which captures the dynamic surface elevations of the Earth’s oceans, lakes, and rivers.
Launched in December 2022, the SWOT satellite is a collaborative mission between NASA and the French space agency CNES. Equipped with a radar instrument capable of measuring water surface heights with high accuracy, the satellite plays a crucial role in creating a global map of water surface elevation. This map enables the tracking of changes in water levels over time, facilitating studies on climate change, drought, and flooding.
During its initial 21-day science orbit from July 26 to August 16, the SWOT satellite acquired this valuable information. The significance of SWOT lies in the fact that water is essential for life on Earth, serving purposes such as drinking, irrigation, and industrial use. Moreover, water plays a crucial role in climate regulation. As the Earth’s climate undergoes changes, the distribution of water across the planet is also shifting. Consequently, some areas face water scarcity while others experience more frequent floods.
By collecting critical data over 90% of the Earth’s surface, the SWOT satellite enables scientists to better understand these changes and develop strategies to adapt to them. The acquired data will illuminate the consequences of climate change and support communities worldwide in preparing for a warming planet.
The SWOT satellite’s Ka-band Radar Interferometer (KaRIn) instrument consists of antennas spaced 33 feet apart, capable of observing and measuring water height in both Earth’s freshwater bodies and the ocean. With its ability to detect small-scale characteristics like eddies, currents, and other features less than 13 miles across, KaRIn focuses on lakes, rivers wider than 330 feet, and even larger reservoirs.
By bouncing radar pulses off the surface of Earth’s water and collecting the signals with its antennas, the satellite collects valuable data. Sweeping an area of approximately 30 miles from both sides of SWOT, the satellite’s operation aims to provide data that aids in addressing climate change and prepares communities for a warmer climate.
The benefits of the new map of Earth’s water resources are substantial. It not only enhances the understanding of the global water cycle and how water moves around the planet but also supports the development of accurate climate change models and predictions regarding the impact on water resources. It aids in identifying areas with water scarcity and assists in the formulation and implementation of effective water management strategies. Additionally, the maps help to identify areas at risk of flooding or drought, enabling proactive preparation and response to these disasters.
Looking ahead, the SWOT satellite is expected to continue collecting crucial data for at least three years, enabling improved accuracy in the global map of water surface elevation and tracking long-term changes in water levels. Furthermore, this data will pave the way for the development of new applications such as water quality monitoring and flood forecasting.
With the ability to highlight ocean currents and temperature variations, the SWOT satellite is an invaluable tool for understanding and managing Earth’s water resources. The new map of Earth’s water resources has significant benefits across multiple disciplines, including science, water management, and disaster response.