Using satellites, the biomass of the northern hemisphere’s forests has been mapped with greater precision than ever before. This improves our understanding of the carbon cycle and our prediction of Earth’s future climate, says the European Space Agency (ESA).
The boreal forest ecosystem – exclusive to the northern hemisphere – spans Russia, northern Europe, Canada and Alaska, with interrelated habitats of forests, lakes, wetlands, rivers and tundra.
With processing software drawing in stacks of radar images from ESA’s Envisat satellite, scientists have created a map of the whole northern hemisphere’s forest biomass in higher resolution than ever before. Each pixel represents 1 km on the ground.
“Single Envisat radar images taken at a wavelength of approximately 5 cm cannot provide the sensitivity needed to map the composition of forests with high density,” said Maurizio Santoro from Gamma Remote Sensing.
“Combining a large number of radar datasets, however, yields a greater sensitivity and gives more accurate information on what’s below the forest canopy.”
About 70,000 Envisat radar images from October 2009 to February 2011 were fed into this new, ‘hyper-temporal’ approach to create the pan-boreal map for 2010.
This is the first radar-derived output on biomass for the whole northern zone using a single approach – and it is just one of the products from the Biomasar-II project.
Sponsored by ESA, the project also exploited Envisat archives to generate regional maps for 2005.