9 Merging regional and global chemistry, air quality and global change: SHARE-Asia in the context of the IGAC project

Abstract

Abstract The International Global Atmospheric Chemistry (IGAC) project was created in the late 1980s to address growing international concerns over rapid changes observed in Earth's atmosphere. Much of IGAC's research effort during its first decade was directed towards assessing the effects of anthropogenic emissions on the background atmosphere. While questions remain concerning the point at which observed global/regional mean trends in component concentrations (signal) unambiguously rise above background natural variability (noise), it is now well recognized that human activities have perturbed the chemical composition of the atmosphere at local, regional, and global scales. Two overarching questions have emerged that constitute the basis for the IGAC action plan over the next decade: (1) What is the role of atmospheric chemistry in amplifying or damping climate change? (2) Within the Earth System, what effects do changing regional emissions and depositions, long-range transport, and chemical transformations have on air quality and the chemical composition of the planetary boundary layer? Within the context of the larger ABC-Asia project, a proposal was put forward for the activation of an ABC-IGAC Task focusing on the monitoring of aerosol and trace gases over the Asia–Pacific region and on estimating their impact on atmospheric chemistry and the radiation budget. The activities currently in progress, to include the Ev-K 2 -CNR Pyramid observatory in the Atmospheric Brown Cloud (ABC) monitoring network under the Stations at High Altitude for Research on the Environment in Asia (SHARE-Asia) project, aim at providing an important contribution to ABC-Asia and, at the same time, will undoubtedly be an opportunity for the Italian community of global-change researchers.