Transport and Atmospheric Chemistry near the Equator-Atlantic

During 1983-2001, NASA conducted a collection of field campaigns as part of the Global Tropospheric Experiment (GTE) to quantify atmospheric trace gases' sources, sinks, and distribution. Among those were the Transport and Atmospheric Chemistry Near the Equator (TRACE) campaigns, which included two missions: TRACE-Atlantic (TRACE-A) and TRACE-Pacific (TRACE-P). TRACE-A took place from September to October 1992 over the tropical Atlantic Ocean, which extends from Brazil to southern Africa. TRACE-A also included flights over South America and Africa. TRACE-A had two scientific objectives: 1) study the photochemical and meteorological features contribution to enhanced ozone concentrations observed over the tropical Atlantic Ocean and 2) characterize and quantify the source and transport of primary and secondary ozone precursors associated with biomass burning in South America and southern Africa. TRACE-A was a collaborative study between NASA and the Southern African Fire-Atmosphere Research Initiative (SAFARI), which formed the main core of the International Global Atmospheric Chemistry's (IGAC's) South Tropical Atlantic Regional Experiment (STARE; August-October 1992). Throughout the campaign, STARE addressed the impact of biomass burning on the biosphere and the atmosphere.

To accomplish its objectives, the TRACE-A Science Team deployed the NASA DC-8 aircraft, equipped with a suite of instruments that were selected based on their ability to produce high-quality measurements of atmospheric components at very low concentrations, which are often observed in the remote troposphere. The in-situ measurements collected by the DC-8 include measurements of ozone and aerosol precursors and oxidants, e.g., NOx, VOCs, hydrocarbons, oxygenated species, as well as greenhouse gases and tracers. The DC-8 aircraft also included a Differential Absorption Lidar (DIAL), which was used for remote sensing of ozone and aerosols by measuring peroxides, carbonyls, and other oxygenated organics. Over the course of the deployment, the DC-8 conducted 17 flights, totaling over 140 hours of flight time. TRACE-A also included significant contributions by the Brazilian Space Agency, National Institutions for Space Research (INPE), and worked in collaboration with other Brazilian agencies and universities. Two Brazilian aircraft were instrumented for measurements, including vertical profiles of trace gases (i.e., CO, O3, N2O, CH4, and CO2), radon, and aerosols (e.g., black carbon). Surface measurements of these species were also made at three locations generally affected by biomass burning within the region: Cuiaba, Goiania, and Porto Nacional, Brazil. Measurements taken at Natal, Brazil also provided important information about the composition of the air in the region, which generally had not been influenced directly by Brazilian burning.

Detailed descriptions related to the motivation, implementation, and instrument payloads are available in the TRACE-A overview paper. TRACE-A overview paper. A collection of the publications based on TRACE-A observations are available in the Journal of Geophysical Research special issues: Southern Tropical Atlantic Region Experiment (STARE): TRACE A and SAFARI.

Disciplines:   Field Campaigns