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Full-Text Articles in Physical Sciences and Mathematics

Terrestrial Exchange Of Atmospheric Metals: Insights From Fallout Radionuclides, Joshua D. Landis Apr 2024

Terrestrial Exchange Of Atmospheric Metals: Insights From Fallout Radionuclides, Joshua D. Landis

Dartmouth College Ph.D Dissertations

Forests mediate the exchange of gases and particulate matter (PM2.5 and PM10) between terrestrial ecosystems and the atmosphere over 30% of global land area. Because forest foliage efficiently absorbs PM with persistent pollutants including metals Pb and Hg, as well as CO2 and gaseous elemental mercury (GEM), this exchange profoundly influences the composition of the atmosphere as well as terrestrial biogeochemical cycles. The processes by which PM is absorbed remain enigmatic, however, due to the complexity of micrometeorological physics and submicron physical scale of the interaction. Here, measurements of fallout radionuclides (FRNs) beryllium-7 and lead-210, which are quintessential tracers …


Geomorphic And Paleoclimatic Implications Of Glacial Extent Records In The Sierra Nevada Del Cocuy, Colombia During Termination 1, Jordan Nickerson Herbert Sep 2022

Geomorphic And Paleoclimatic Implications Of Glacial Extent Records In The Sierra Nevada Del Cocuy, Colombia During Termination 1, Jordan Nickerson Herbert

Dartmouth College Master’s Theses

Reconstructions of past glacial extents using geomorphic mapping and cosmogenic dating provide an opportunity to infer past climates. A record of the past extents of tropical mountain glaciers is particularly useful because there are few other means to reconstruct past temperatures in high-altitude, low-latitude locations. The tropics play an outsized role in mediating global climate, yet there is a lack of understanding of how the tropics may have influenced past climate changes such as the most recent deglaciation (Termination 1, ~18–11.7 ka). Improving reconstructions of tropical mountain glaciers will aid in understanding the role of the tropics in the global …