In 1986, chlorofluorocarbons (CFCs), chemical compounds known to break down ozone in the atmosphere, were banned by the Montreal Protocol. This led to an immediate rapid decline in emissions. However, recent studies have shown that CFC-11 emissions have increased, suggesting a contribution from eastern Asia.
To investigate this claim, UMD Department of Atmospheric and Oceanic Science researchers Sarah E. Benish, Ross J. Salawitch, Xinrong Ren, Hao He, and Russell R. Dickerson examined airborne observations of CFCs and other halogen-containing compounds over the Hebei Province of China, the region identified with likely new production of CFC-11. Dickerson and Salawitch are also Professors at ESSIC/CISESS.
In Spring 2016, 27 whole air samples were collected from an aircraft over Hebei Province in China and analyzed for 16 halocarbons. The researchers found high mixing ratios of many compounds well above the global tropospheric background, leading to the conclusion that emission and possible new production of CFCs continued during Spring 2016 despite global phaseout. The largest mixing ratios of CFCs are traced to Inner Mongolia, Shandong, and Hebei. Evidence of new production of CFC-11 and CFC-12 are throughout eastern China, while new production of CFC-114 is limited to flow from the southeast.
Dickerson is an air quality modeler in the AOSC Atmospheric Chemistry group and the ESSIC Earth System Modeling (EaSM) group. His research focuses on improving numerical simulations of air quality based on campaign measurements and satellite observations at the regional scale.
Salawitch is a professor in the Department of Atmospheric & Oceanic Science and the Department of Chemistry and Biochemistry. His research focuses on quantification of the effects of human activity on atmospheric composition.
To access the article, click here: “Airborne Observations of CFCs over Hebei Province, China in Spring 2016”.