Persistent organic chemicals in high-altitude atmosphere and ecosystems

Persistent organic chemicals (POCs) were recently found at high altitudes affected by the free troposphere (FT) at the world’s highest atmospheric observatory (5240 masl), the Chacaltaya GAW station (CHC) in Bolivia. POCs that reach the FT can be efficiently transported over hemispherical distances and deposit in very remote, often vulnerable/less-resilient high altitude locations. For some POCs, the FT could be a critical long-range transport medium and lead to increasing POC contamination and subsequent risk to humans and ecosystems at high attitudes. However, little work has focused on understanding FT-mediated pollutant transport and distribution due to a lack of footholds at high altitudes for long-term and large-scale studies. We will study atmospheric composition and atmosphere-ecosystem interactions of POCs with varying physical-chemical properties and chemical structures using the unique capability of the CHC for long-term studies in a high-altitude environment. Moreover, we will collaborate with alpinists to extend our research scale to two remote 6500 masl Bolivian mountains far from the CHC. Based on the temporal, spatial, and altitudinal experiments, we will develop a mechanistic and quantitative understanding of POC behaviors in the FT and high-altitude environments. We will apply the results in a transport model to examine POC transfer in the high-altitude atmosphere on the global scale.