GC031-04
Tracing Past and Present Air Pollution Sources Using Ice Core Records from High-Mountain Glaciers

Tuesday, 8 December 2020: 16:12
Virtual
Maria Roxana Sierra-Hernandez1, Emilie Beaudon2, Stacy E Porter3, Paolo Gabrielli3, Ellen Mosley-Thompson4 and Lonnie G Thompson5, (1)The Ohio State University, Columbus, OH, United States, (2)Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH, United States, (3)The Ohio State University, Byrd Polar and Climate Research Center, Columbus, OH, United States, (4)Ohio State University Main Campus, Department of Geography, Columbus, OH, United States, (5)Ohio State University Main Campus, School of Earth Sciences, Columbus, OH, United States
Recorded Presentation
Abstract:
Air pollution is of great concern because it can affect human health, climate, and the environment. Air pollutants originate from anthropogenic and natural sources and can be directly released into the atmosphere as gaseous compounds, particulate matter, black carbon, and organic carbon. They can be transported long distances depending on their physical and chemical characteristics and the prevailing meteorological conditions. Atmospheric monitoring programs and emission inventories have been conducted but are only available for recent decades with varying spatial and temporal resolutions. Thus, natural archives such as ice cores are necessary to trace the spatial and temporal sources of air pollution and to contextualize long-term trends.

In China and South Asia, fossil fuel consumption and deforestation have increased dramatically since the 1970s worsening local and regional air quality. This presentation will highlight histories of trace elements, which can be used as tracers of forest fires (e.g., Mn, Zn) and coal combustion (e.g., Cd, Pb, Sb, Zn), from ice cores retrieved from Tibet and the Himalayas. In particular, records of Cd, Pb, and Zn from the Guliya ice cap in northwestern Tibet, covering the 1971-2015 period, reveal that emission changes in Asia have impacted remote high-altitude glaciers in northwestern Tibet.

In North America, fossil fuel consumption has increased since the Industrial Revolution, but contrary to China and South Asia, the air quality improved after the introduction of the Clean Air Act of 1970. However, forest fires in boreal North America have increased since the 1980s and although they are a natural occurrence of forest ecosystems, human activities have influenced their regime. Using a continuous, high-resolution ice core-derived record of black carbon (~1930-2001 CE) from Bona-Churchill in southeastern Alaska, the possible sources of black carbon will be explored to reconstruct a fire history and determine the factors influencing the 20th century fire regime in southeastern Alaska.

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