Publications by authors named "S Ehrhart"
Article Synopsis
- Ammonia emissions in Southeast Asia significantly impact air pollution and the development of the Asian Tropopause Aerosol Layer (ATAL), particularly during summer when the South Asian monsoon is active.
- The study utilizes the EMAC chemistry-climate model to analyze how ammonia influences particle formation, revealing a tenfold increase in particle creation during the day, especially within the monsoon's upper troposphere and lower stratosphere (UTLS).
- Findings indicate that while ammonia enhances cloud condensation nuclei (CCN) concentrations and aerosol optical depth (AOD), its effect on aerosol mass in the ATAL is comparatively limited, suggesting a complex relationship between ammonia, particle growth, and aerosol composition.
Social-ecological systems are characterized by complexity, uncertainty, and change. Adaptive co-management may help to improve adaptability and resilience and to develop 'no-regret strategies' for a sustainable management. It is a dynamic, inductive, and self-organized process based on social learning and collaboration.
View Article and Find Full Text PDFBinary nucleation of sulphuric acid-water particles is expected to be an important process in the free troposphere at low temperatures. SAWNUC (Sulphuric Acid Water Nucleation) is a model of binary nucleation that is based on laboratory measurements of the binding energies of sulphuric acid and water in charged and neutral clusters. Predictions of SAWNUC are compared for the first time comprehensively with experimental binary nucleation data from the CLOUD chamber at European Organization for Nuclear Research.
View Article and Find Full Text PDFFundamental questions remain about the origin of newly formed atmospheric aerosol particles because data from laboratory measurements have been insufficient to build global models. In contrast, gas-phase chemistry models have been based on laboratory kinetics measurements for decades. We built a global model of aerosol formation by using extensive laboratory measurements of rates of nucleation involving sulfuric acid, ammonia, ions, and organic compounds conducted in the CERN CLOUD (Cosmics Leaving Outdoor Droplets) chamber.
View Article and Find Full Text PDFArticle Synopsis
- * Model simulations indicate that these biogenic particles significantly increased cloud condensation nuclei (CCN) concentrations in the preindustrial era, leading to a greater cooling effect on the climate due to higher cloud albedo.
- * The research suggests that the overall impact of human-made aerosols on climate may be less than previously thought because of the substantial role of natural processes, highlighting the need for more research on these natural aerosol formation mechanisms.