Washington: Thanks to satellites, the biomass of the northern hemisphere`s forests has been mapped with greater precision to help improve our understanding of the carbon cycle and our prediction of Earth`s future climate.
Accurately measuring forest biomass and how it varies are key elements for taking stock of forests and vegetation.
Since forests assist in removing carbon dioxide from the atmosphere, mapping forest biomass is also important for understanding the global carbon cycle.
In particular, northern forests - including forest soil - store a third more carbon stocks per hectare as tropical forests, making them one of the most significant carbon stores in the world.
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," Maurizio Santoro from Gamma Remote Sensing said.
"Combining a large number of radar datasets, however, yields a greater sensitivity and gives a more accurate information on what`s below the forest canopy," Santoro said.
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.