The Amazon Tall Tower Observatory, or ATTO, is a scientific research facility in the Amazon rainforest of Brazil. This includes a 325-meter-tall tower that extends far above the forest canopy and two 80-meter towers that allow researchers to collect samples from the soil surface to above the forest canopy.

Additionally, there are climate-controlled containers for laboratory equipment and an office, a base camp and nearby sites for studying vegetation and soil processes. The tall research tower is one meter taller than the Eiffel Tower and is currently the tallest structure in South America. All towers are equipped with a wide range of instruments to measure the chemical and physical properties of the atmosphere, such as greenhouse gas concentrations, aerosols, and meteorological data.

The observatory is a joint project between Germany and Brazil, coordinated by the Max Planck Institute for Biogeochemistry on the German side and the Brazilian National Institute of Amazonian Research, INPA (Instituto Nacional de Pesquisas da Amazônia), on the Brazilian side. Other major research partners include the Max Planck Institute for Chemistry and the University of the State of Amazonas, with over 20 research institutes and universities in Brazil, Germany, and other countries participating. The initial building cost of 8.4 million euros was shared about equally by the German and Brazil partners.

The towers are used to study the interactions between the forest and the atmosphere. Researchers continuously measure greenhouse gases, aerosols, and weather data, both during field campaigns and in the lab. They provide information about a roughly 100 km² area of largely pristine rainforest. This phenomenon is especially true during the wet season when the direction brings mostly "clean" air to the site that resembles the pre-industrial atmosphere.

The project is also dedicated to the exploration of how the rainforest biosphere responds to global warming. According to the German Federal Ministry of Education and Research (BMBF), ATTO enables new levels of measurements of the complex interactions between the land surface and the atmosphere. Furthermore, the research project studies chemical and physical processes over the Amazon which affect the climate.

According to en.wikipedia.org