NASA Grant Enables Amazonian Research

WHRC is proud to announce that Senior Scientist Michael Coe has been awarded a grant from NASA to conduct research into the effects of land use change on climate in the Amazonian agro-frontier. Collaborating with Dr. Coe on the project are WHRC Deputy Director Scott Goetz and Research Associate Pieter Beck, and Brazilian colleagues Britaldo Soares-Filho and WHRC Distinguished Visiting Scientist Paulo Brando. Their research will reveal the current and possible future effects of deforestation in the region. Read on to learn more …

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This figure shows annual total evapotranspiration in mm (top panels) for the entire Amazon basin (left) and the Xingu River basin (right). Fractional forest cover in the year 2010 is also shown (bottom panels) for the Amazon and Xingu River basins. As illustrated in the Xingu River basin (right panels) deforestation of evergreen forest (shown in bright colors in the bottom right panel) significantly reduces evapotranspiration (bright colors in the upper right panel). Evapotranspiration is created from the 1-km resolution, monthly MODIS16 product. Forest cover is from the annual, 250-m resolution MOD44B vegetation continuous fields product. Click for larger image.

When Dr. Michael Coe visits the Mato Grosso region of the Amazon in Brazil, his days are spent taking care of some pretty mundane tasks—placing gauges in streams and forest, and collecting data from soil pits. “As a scientist whose research focuses on complex computer models, friends ask me why I spend so much time in the field,” says Dr. Coe. The short answer is that he has to know how the earth works if he wants to accurately represent data on a computer.

Dr. Coe uses the information to develop models that tell us how the land surface interacts with climate. These models in turn rely on accurate information about how plants take up water from the soil and transpire it to the air, and how water that isn’t used by the plants flows through the soil, across the land and via rivers into the ocean.

Until recently, scientists were unable to measure the effects of land use change on ecosystem processes, but the availability of satellite imagery such as MODIS (Moderate Resolution Imaging Spectroradiometer) that now spans a ten-year period, offers new opportunities to not only map these complex dynamics, but also to quantify their consequences for the regional energy balance.

MODIS is an instrument placed on both the Terra and Aqua satellites, with the orbits of these two satellites timed so that the Earth’s entire surface is viewed every two days, collecting data in 36 groups of wavelengths. The information these wavelengths provide tells us a great deal about the vegetation, how it cycles energy and water, and how it changes in time. WHRC scientists combine this knowledge with a dynamic vegetation model to quantify the influences of the land use change in the southeastern Amazon, where deforestation rates are greatest.

The overarching questions to be answered by this research are: How does historical and future land use change affect the regional energy and water balance in Amazonia, and how do these effects compare with those changes we expect from increased atmospheric CO2 concentration?

The recent expansion of pastures and agricultural monocultures has resulted in 730,000 km2 of the Amazon Basin being deforested. Despite recent declines in the rates of forest clearing, the deforested area of the Amazon Basin is expected to continue to expand. Influences of land use change on ecosystem processes are therefore expected to become even more important for the region as forest is converted into pasture and crops. This research will provide critical insights into these changes and, ultimately, how they might alter regional and global climate and carbon cycles.

“One of the most important aspects of fieldwork is the simplest,” says Dr. Coe. “Just getting out of the office and seeing the natural world opens my eyes. It’s important to know what clouds do as they form rain over soy or degraded forest and healthy forest – the two are very different. All of these things come back as I sit at my desk writing computer code.”