# Atmospheric & Environmental Chemistry Seminar #### calendar\_today Date and Time **October 8, 2021** 12:00PM - 01:00PM EDT [ Registration arrow\_circle\_right ](https://harvard.zoom.us/meeting/register/tJclcemvrj8qH9dd1MH0vBqTWW2ay0SUMJQK) "Cycling and Sources of Mercury in Terrestrial Ecosystems" with **Daniel Obrist**, Professor, University of Massachusetts, Lowell. "Cycling and Sources of Mercury in Terrestrial Ecosystems" with **Daniel Obrist**, Professor, University of Massachusetts, Lowell. The terrestrial environment is an important component of the global Hg cycle and is estimated to receive 3,600 Mg of atmospheric Hg deposition annually, equivalent to about half of total annual Hg emissions to the atmosphere from anthropogenic and natural sources combined (with the remainder depositing to global oceans). Atmospheric Hg deposition includes wet deposition via precipitation and snow and dry deposition, which includes removal of particulate Hg and sorption and uptake of gaseous Hg to earth’s surfaces. Multiple lines of evidence now show that dry deposition of gaseous elemental Hg (GEM) is the dominant Hg source to terrestrial environments whereby atmospheric GEM is taken up by vegetation tissues and subsequently transferred and deposited to soils when tissues are shed (litterfall), plants die off (biomass turnover), and leaf surfaces are washed off (i.e., throughfall). Here, we present an update of our understanding of how GEM is cycling through the terrestrial environment, including: new estimates of GEM uptake by global biomes; processes and partitioning of GEM deposition in ecosystems; and emerging datasets of atmosphere-surface flux measurements to directly quantify whole ecosystem GEM sinks and sources. [Registration](https://harvard.zoom.us/meeting/register/tJclcemvrj8qH9dd1MH0vBqTWW2ay0SUMJQK) is required. Open to the Harvard community. For event details, visit [the event page](https://events.seas.harvard.edu/event/guest_speaker_daniel_obrist_professor_university_of_massachusetts_lowell). Contact: See also:- [ Ecology & Biodiversity ](/research-areas/ecology-and-biodiversity) - [ Harvard Paulson School of Engineering and Applied Sciences ](/school/harvard-paulson-school-engineering-and-applied-sciences) Share on:- [ Facebook ](#) - [ Twitter ](#) - [ Linkedin ](#) Save: [ Add to calendar calendar\_today ](https://www.environment.harvard.edu/node/1418104/event-feed.ics) Copy link link