The postdoc will join a strong and long-standing research program focusing on the interlinkages between severe air pollution and climate change in South Asia. To reduce uncertainties, there is need for field-observation-based constraints. This project is focused on leveraging multi-isotope techniques (e.g., δ13C, δ2H, δ18O, Δ14C) to advance constraints on the sources and atmospheric fate of key target gases such as methane, carbon monoxide and others in the highly perturbed atmosphere of South Asia. The combination of strategically located regional source and receptor sites with advanced isotope techniques will allow detailed characterization of sources, atmospheric reactions and overall constraints of the lifecycle of these gases of large importance for the changing climate.