• The objective of MAGE was to study air-sea exchange and the formation and transformation of marine aerosols in part by making Lagrangian observations. MAGE organized the chemical experiment of The Atlantic Stratocumulus Transition Experiment (ASTEX), which took place in June 1992 in the stratocumulus-capped marine boundary layer. The purpose was to study the factors influencing the formation and dissipation of marine clouds. MAGE also organized an intercomparison experiment, ASGAMAGE, which had two phases, the first in May and the second in October of 1996.

  • The Mega-cities: Asia Task Team facilitated better coordination between groups making measurements of aerosols and oxidants in and around large cities in Asia. Their activities included maintaining a centralized web page; holding periodic workshops to increase communication between research groups; organizing instrument intercomparisons; and facilitating collaborative publications.

NARE was an experiment that was implemented from 1991-1994 that was created through the merging of Atmosphere/Ocean Chemistry Experiment (AEROCE), which became a critical component of the project. It was established to study the chemical processes of the marine troposphere most impacted by industrial emissions. The primary objective was to investigate the chemical and transport processes that shape ozone distribution over the North Atlantic and to estimate the impact of human-induced emissions from North America and Europe on the production of tropospheric ozone and related parameters.


The Ocean – Atmosphere – Sea Ice – Snowpack (OASIS) program was created in 2002 to bring together an international group of multidisciplinary field researchers, laboratory scientists, and modelers to study chemical and physical interactions and exchange processes between the title reservoirs, with a primary focus on the impact on tropospheric chemistry and climate feedbacks.


  • PASC began in the early 1990s working towards coordinating polar tropospheric and snow/ice chemistry research. PASC helped identify knowledge gaps in polar atmosphere and snow chemistry along with aiding in understanding the role of tropospheric chemistry of Polar Regions in global change. PASC used atmospheric measurements and ice core records to analyze the human-induced changes of the polar atmospheric environment. A key research development was the measurement of the atmospheric composition of the middle to upper troposphere at the Summit in the Northern Hemisphere.

  • Advanced research on the dispersal and decay mechanisms for stratospheric aerosols. SUTA sought to find out if stratospheric aerosols serve as nuclei for cloud formation in the upper troposphere and stratosphere and if there is “background” stratospheric aerosol, what the source is. SUTA sought to find out if volcanic emissions on the stratosphere are adequately characterized in current models. SUTA also sought to find out if stratospheric aerosols are frozen or if they exist as supercooled liquid particles at low temperatures.

TRAGEX sought to improve the understanding of increased concentrations and fluxes between the soil and atmosphere of trace gasses such as CO2,, CH4, N2O impacts on climate and precipitation. TRAGEX studied the factors controlling the fluxes and improved the ability to predict future fluxes. The project greatly improved understanding of the fluxes of these gasses in areas such as Russia, China and temperate South America, which were largely unknown prior to TRAGEX.


TARFOX was an IGAC activity that operated from 10-31 July 1996 and was established to provide information about the direct effects of tropospheric aerosols on the eastern seaboard of the United States. The principal goals were to:


As of 2008, for the first time, the majority of the world’s population was living in urban areas, many in megacities (with populations over 10 million). Megacities are not only the center of growing economies, but are also large sources of air pollutants and climate-forcing agents.


TOAR Assessment Report:  Papers published so far
The assessment report is being published as a series of papers in the peer-reviewed journal, Elementa – Science of the Anthropocene.   Papers published so far are available through a Special Feature of Elementa: