- ACE-1, part of the larger ITCT initiative, was the first of a series of studies that analyzed the indirect effects of anthropogenic aerosols through cloud modification. ACE-1 took place from October to December 1995 across the Pacific Ocean and south of Australia. The experiment focused on the minimally polluted marine atmosphere, creating an opportunity to be able to study the natural aerosol system and its chemical, physical, and radiative and cloud nucleating properties. ACE-1 provided a background to be able to compare and quantify any anthropogenic perturbation and study progressively more complex environments.