Scientists will participate in a mission to 3D map the world’s most remote, dense, and darkest tropical forests from outer space. The feat will be achieved thanks to a special radar scanner fitted to Biomass, the latest in a series of Earth Explorer modules that will be fired into orbit later this month.
For the next five years, the 1.25-tonne spacecraft will sweep over the tropical rainforests of Africa, Asia, and South America, peering through dense 40m-high canopies to study the vegetation beneath. The data collected by the mission will then be used to create unique 3D maps of forests hidden from human sight.
Less than 2% of sunlight reaches the forest floor in these regions, yet Biomass will study them in unsurpassed detail from a height of more than 600km. More importantly, the mission will allow scientists to calculate how much carbon is stored in the forests and measure how levels change as humans continue to cut down trees in the tropics and increase carbon dioxide levels in the atmosphere.
In addition, Biomass—built by a consortium led by Airbus UK and funded by the European Space Agency (ESA)—will map the subsurface geology and topography of forest floors and provide data about the rate at which biodiversity is being lost as forests are cleared for mining and agriculture.
“We need to know the health of our tropical forests,” Simonetta Cheli, director of Earth Observation Programmes for Esa, told the Observer last week: “We need to know the quality and diversity of its vegetation and the amount of carbon stored there. To get that information, we will create 3D images of them – from the top of the forest canopy to the roots of its trees.”
Tropical forests play a crucial role in protecting the planet from some of the worst effects of global warming because they absorb so much carbon dioxide from the atmosphere: estimates suggest they take up about eight billion tonnes and are described as the Earth’s green lungs. However, deforestation and environmental degradation reverse this effect.
Bjorn Rommen, mission scientist for the Biomass project, said quantifying the problem is essential for forecasting what will happen to Earth’s climate in coming years: “We don’t properly understand what changes are now taking place, partly because we do not have accurate estimations of carbon levels in these forests. Biomass will help us get a better grip on those numbers.”
Launching from ESA’s spaceport near Kourou in French Guiana on April 29 aboard the VegaC rocket, it will carry a radar known as a P-band synthetic aperture radar. Its long wavelength signals will allow it to peer down through canopies to assess how much carbon is stored on the floor and branches of the trees in the world’s tropical forests and how levels change. This type of radar has never been flown in space before and has required Biomass to be fitted with a giant 12m antenna, which will be deployed as the spacecraft begins its sweep over the Earth.
“What the mission will do, effectively, is weigh the forests it studies,” said the leader of the Biomass science team, Prof Shaun Quegan, of Sheffield University. “We know half that weight must be made up of carbon. So we will be able to weigh the carbon content of the world’s tropical forests from space and, crucially, determine how much these are changing over time. We will then know the balance of carbon flowing to and from the atmosphere. That is enormously important.”
A point supported by Cheli: “We need to be able to predict what the Earth will look like as temperatures rise. So we are going to integrate its data with AI and with other digital elements of machine learning and that will tell us what is likely to happen in future. It will tell us what we are up against.”
- To learn more about the project, click here to visit ESA’s Biomass website.
