Summary

Emerging evidence suggests the Amazon rainforest's ability to absorb carbon is weakening, potentially becoming a source of emissions. Despite this, significant uncertainty remains regarding about the region’s current and projected greenhouse gas (GHG) emissions. To address this gap, the Carbon Amazon Rainforest Activity project is collecting new and detailed observations to improve understanding of GHG emissions trends from natural sources in the Amazon through combined ground, airborne, and satellite observation campaigns across a 100 × 100 km area of the eastern Amazon, Pará State, Brazil.

This study is led by King’s College London and is a collaboration between ESA, research institutions from ESA Member States and Brazil’s National Institute for Space Research (INPE) and Federal University of Western Pará (UFOPA).

Rationale

In its Strategy to Support the Global Stocktake of the UNFCCC Paris Agreement, the Committee on Earth Observing Satellites (CEOS) identifies the Amazon as a potential tipping point of terrestrial carbon emissions in the near future. Despite this, significant uncertainty remains regarding about the region’s current and projected greenhouse gas (GHG) emissions. To address these gaps, CEOS has called for a large-scale field experiment to provide new and detailed observations that improve scientific understanding of emission trends from natural sources in the Amazon Basin. Specifically, to better understand the carbon dynamics in carbon stocks and fluxes (CO₂, CH₄, N₂O) associated with different land cover types and fire.

This project responds directly to this call. It is a collaborative field study involving research institutions from across Europe and Brazil and has been designed to generate new and detailed observations to support assessment of GHG emissions in the Amazon. By integrating ground-based (proximal and in-situ), airborne (remote sensing and in-situ), and satellite observations, the project aims to improve understanding of natural emissions processes and their responses to ongoing environmental change.

Science objectives & experimental set up

The project comprises a campaign of concurrent airborne sorties and satellite overpasses over an instrumented over the eastern Amazonian study area, around the city of Santarém, Para State.

Ground-based sensors in fixed locations have been deployed in primary and secondary forest, while mobile or ‘roving’ measurements will be used to complement assessment of fire impact around Santarém.

The airborne campaign will study and characterise the region's land area from above using a variety of advanced remote sensing methods, whilst simultaneously sampling the atmosphere to measure the land-atmosphere transfers of greenhouse gases, particulates and various air pollutants, both in and out of primary and degraded forest and also from the regions fires. Airborne activities have been made possible through close cooperation between ESA, participating European research teams, Brazil’s National Institute for Space Research (INPE) and Federal University of Western Pará (UFOPA) – one of the few times such research has been allowed in recent decades.

Science goals

The campaign's science goals aim to improve GHG quantification and Verification, improve fire impact assessment, and support both satellite validation and model development and is focussed across three process-related Science Themes

(I) Landscape Scale (non-Fire) GHG Fluxes

(II) Vegetation Processes and Carbon Storage, and

(III) Fire Magnitude, Emissions and Impact