Science for Brazil (Reino Unido)

‘Green Ocean’ Probes Amazonian Climate Change

Publicado em 27 março 2014

‘Green Ocean’ is a fitting description of the impressive sight facing anyone who has flown in a light aircraft over the Amazon rainforest, searching hopefully for a small landing strip.

For some time the label has also been used by earth atmosphere researchers to describe the whole complex process whereby water cycles and recycles between tropical clouds and the forest canopy below. Just like the formation and precipitation of clouds over open oceans, the dynamics of the Amazon biosphere are complex – and central to global warming studies.

Which is why international scientists in January 2014 initiated a major research campaign called Green Ocean Amazon (GOAmazon).  The scientific campaign is financed by the U.S. Department of Energy (DOE), FAPESP and the Amazonas Research Foundation (FAPEAM). Partners also include the National Science Foundation (NSF) of the United States, the Brazilian Innovation Agency (Finep), the Max Planck Institute of Physics of Germany and several Brazilian and US universities and research institutions.

It follows a decade of research into the way rainfall patterns develop over Amazonia  – and how they may be influenced by the presence of particulates from atmospheric pollution, and above all from the burning of forest biomass. Perhaps the most controversial of all branches of scientific study is the effect that human-induced burning and destruction of the Amazon forest may have on global warming and continental weather patterns.

The behaviour of rainfall over tropical forests was first described in 2004 in an article published in the journalScience by researchers who took part in the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA), an international collaborative program led by Brazil.

These studies showed that the clouds hanging over the Amazon rainforest have characteristics similar to those of clouds found over oceans. Because there is a great deal of moisture in the air and an extremely low concentration of particulate matter – which offers a surface for water vapor condensation – raindrops rapidly increase in size and soon acquire sufficient mass for precipitation.

The same study posited that the burning of biomass would create a larger number of water condensation nuclei and, consequently, reduce the size of the drops, slowing the entire process of precipitation.

The onset of drought years in Amazonia – and the resulting die-back of forest cover – has been a subject of continuous study. Recently there have been some remarkable about-turns in articles published by Nature, as scientific errors in interpreting satellite-based research have come to light. You can find out more by clicking here.

To test the theory that the urbanization of the planet’s tropical regions affects local ecosystems and the global climate, nearly 100 researchers from the United States and Brazil who are part of the Green Ocean Amazon (GOAmazon) project will transform the region of Manaus, in the Brazilian state of Amazonas, into a model laboratory.

The city of Manaus and its surrounding areas constitute an ideal laboratory for this type of research. The capital of Amazonas state, with a number of power plants, nearly two million inhabitants and 600,000 cars, all generating particulates and  industrial pollution.

Yet the city is surrounded by  a “green ring” of 2,000 kilometers (km) of forest, and during the rainy season, the levels of particulate material in the region are as low as those in pre-industrial times. Several studies will be conducted throughout 2014 and 2015 at four different sites within a radius of 150 kilometers of the Amazonas capital for the purpose of understanding, for example, the interaction between pollution particulates, compounds naturally emitted by the tropical forest and clouds.

The lead researcher is Scot Martin – a Harvard University professor and the mastermind of GOAmazon. In 2010, Martin submitted a proposal to the DOE to bring the infrastructure of the Atmospheric Radiation Measurement (ARM) Facility – a mobile set of terrestrial and aerial equipment for climate studies, especially those geared to the process of cloud formation and radiation transfer – to Brazil.

Now Martin and his leading Brazilian research counterpart Paulo Artaxo, a professor at the Physics Institute of the University of São Paulo (USP) and coauthor of the study published in Science, have a full-sized internationally-backed project on their hands.  The GOAmazon project was officially launched in Manaus February 18, 2014, at the National Institute for Research in the Amazon (Inpa), one of the partners.

A month earlier, the ARM Mobile Facility (AMF) began to be installed in the city of Manacapuru, nearly 100 km west (downwind) of Manaus. The site was selected because for nearly half the year, it receives the pollution plume from the capital carried by tropical winds that blow from east to west. The rest of the time, the region receives only very clean air; thus, it is possible to compare the two situations.

The mobile observatory consists of 11 containers full of sensors, radars and other equipment for collecting and analyzing aerosol particulates and the variety of gases present in the atmosphere, in addition to measuring cloud properties and meteorological parameters, such as temperature, humidity and wind speed. Four additional containers were installed at the research site, which was given the name T3, by the Brazilian partners of the GOAmazon program.

“This program addresses a global problem. As such, there needs to be a sharing of efforts, competencies and investments to confront the type of challenges that guide GOAmazon. They are challenges that generally have no borders, and the consequences of climate change affect everyone,” said Odenildo Teixeira Sena, secretary of science, technology and innovation of the state of Amazonas during the roundtable discussion.

“The Amazon is a matter of priority for us at the DOE, and we know that the challenge will not be met without this type of partnership,” said Sharlene Weatherwax, associate director of the Office of Biological and Environmental Research of the DOE.

Reynaldo Victoria, member of the coordinating office of the FAPESP Research Program on Global Climate Change (RPGCC), represented the São Paulo foundation at the event and underscored the entity’s satisfaction with the partnership. “We are very interested in expanding this type of collaboration because only by working together will we be able to achieve something better for Brazil and for science,” he stated.

Since the original funding decisions were made in 2013 six projects have been approved on the Brazilian side, and others are already underway, such as the thematic project “Cloud processes of the main precipitation systems in Brazil: a contribution to cloud-resolving modeling and to the GPM (Global Precipitation Measurement),” which is coordinated by Luiz Augusto Toledo Machado of the National Institute for Space Research (Inpe), and the thematic project “GOAmazon: interactions of the urban plume of Manaus with biogenic forest emissions in Amazonia,” which is coordinated by Paulo Artaxo and Maria Assunção Faus da Silva Dias of the USP Institute of Astronomy, Geophysics and Atmospheric Sciences.

The infrastructure for GOAmazon data collection also includes two towers installed in Manaus, two weather balloons and two research planes.

Another project underway within the scope of GOAmazon, coordinated by Jeff Chambers of the Lawrence Berkeley National Laboratory, an entity associated with the DOE, is designed to further study the functions of VOCs on plant physiology and understand how the emissions change according to the amount of sunlight and rain and how all of this affects the forest ecosystem. Measurements are being taken at a set of towers located 50 km north of Manaus, near kilometer 34 of a dirt road known as ZF2.
Another set of towers used by the group is located at the Uatumã Biological Reserve, a forest area 160 km northeast of Manaus, an area untouched by urban pollution. At that site, called T0, a 320 meter-high observation tower is under construction, part of the Amazonian Tall Tower Observatory (ATTO), a partnership between the National Institute for Research in the Amazon (Inpa) and the Max Planck Institute of Chemistry, Germany.

The major investment being made by international partners in the Amazon research project provides confirmation of the growing certainty that the region  has a key role to pay in unlocking the mysteries of man-made climate change. And the “Green Ocean” provides an idea laboratory to test the effects of industrial pollution on the pristine tropical forest.

“If pollution is in fact altering the characteristics of the clouds in Amazonia, the consequence will be a significant change in rainfall patterns,” said prof Artaxo.

You can read two detailed articles on GOAmazon by Brazilian journalist Karina Toledo, including her reports from Manaus and the project site.

Click here for: “Amazonia is Model Laboratory for Researchers.”

Click here for: Task Force Investigates if Amazonia’s ‘Green Ocean’ at Risk.”