Artist's illustration of the SWOT spacecraft. (CNESHED) | SkyNews
Artist's illustration of the SWOT spacecraft. (CNESHED)

SWOT satellite ready to watch Canadian waters

The spacecraft will provide much-needed data on changes in our lakes and coastlines.

The impact of climate change in Canada is significant, but its effect on coastline and lakes is hard to predict. Part of that issue stems from the effort required to get researchers to survey the water in person: Canada is nearly 10 million square-kilometers in size and many of its waters are in remote areas. 

But there is a solution; NASA and the French space agency (Centre national d’études spatiales) are partnering on a mission known as Surface Water and Ocean Topography (SWOT), and which is slated to launch on December 15. The mission aims to assess surface waters around the world and publish the data openly for any community to use for water management.

According to NASA, “Scientists plan to use its observations to better understand the global water cycle, furnish insight into the ocean’s role in how climate change unfolds, and provide a global inventory of water resources.”

That focus on water will be especially crucial to Canada, which has nearly 900,000 lakes that are roughly 10 hectares or larger in area, according to Canadian Space Agency (CSA) figures. Canada is contributing a radar instrument to SWOT that can look over wide regions at a time, which follows on from decades upon decades of radar instruments on Earth and in orbit — most famously with the RADARSAT series of satellites.

The Canadian instrument set is called Extended Interaction Klystron or EIK. Simply put, these EIKs will boost power to microwave pulses that will sweep our planet’s surface in search of water surface elevation. 

“We have a number of Canadian scientists from various universities — and government scientists,” said Jean Bergeron, mission scientist at the CSA, in an interview with SkyNews. The collaborators will use ground measurements, where available, along with models and other tools to make sure the spacecraft is doing measurements as predicted.” 

“One advantage that this involvement has given us is being there from the beginning, to define what the mission objectives are and to ensure that it answers some of our needs as well,” Bergeron added. 

Canada has a poor understanding of how its lakes and coastlines are performing under climate change conditions. They may find the data valuable for applications like water or wildlife management, depending on what is found.

SWOT is expected to last at least three years in orbit, but the first six months or so will be a calibration and validation period. This is needed to make sure the satellite is working as expected before asking it to take on new scientific work.

Activities during this period will include ensuring the instruments and components are working, and adjusting SWOT’s orbit to more global coverage. At first it will fly over regions of the world, revisiting some areas daily instead of every 21 days. That timing is important to assess its ability to collect data while “revisit rates” are high, allowing for quick adjustments if or when needed.

These are early days, but the expectation is that SWOT could help scientists generate flood warning systems, better monitor sea level and ocean currents, and manage water resources. That will have positive ripple effects, according to the CSA — for shipping, wildlife and resource management, and for ensuring the North is better protected.

This biweekly column by Canadian science and space journalist Elizabeth Howell focuses on a trending news topic in Canadian astronomy and space.