Composition Measurements (CM)
Knowledge of atmospheric composition is critical to our understanding of the atmosphere. High-quality time series of measurements, along with critical analysis and evaluation, are essential as a means to further understanding. On the global front, PEARL measurements include Essential Climate Variables (ECVs) defined by the Global Climate Observing System. This theme has four projects: Greenhouse Gases Related to the Carbon Cycle (CM-GHG); Ozone and Related Species (CM-O3); Biomass Burning and continental influence on the Arctic (CM-BB); and Clouds, Aerosols and Precipitation (CM-CAP).