News & Events

Grad student talk - Fate and transport of DOM in the Okavango Delta and McMurdo Dry Valleys

Thursday, September 11, 2014, 4:30PM - 5:30PM

Speaker

Jessica Ebert

Location:

RL-1 room 269

Full title

Fate and transport of DOM in 2 field sites, the Okavango Delta, Botswana and the McMurdo Dry Valleys

Abstract

Dissolved organic matter (DOM) is present in all aquatic ecosystems and plays an important role in the global carbon cycle. DOM is comprised of a complex, heterogeneous mixture of organic compounds derived from both microbial and terrestrial sources and in analyzed using fluorescence spectroscopy. The focus of my research is the fate and transport of DOM through two different systems, one complicated and one that is more simplified.

The more simplified site is Lake Hoare, located in the McMurdo Dry Valleys, Antarctica is a perennially ice covered lake that occupies a 4-km-long, closed-basin fed by a glacial meltwater stream called Andersen Creek, runoff from the Canada Glacier, and overflow from an adjacent pond, Lake Chad.  The DOM at this site is microbially produced due to the complete lack of terrestrial plants. As the stream water enters the lake system it is pushed into a mixing zone where DOM is being transformed from dilute stream water to more concentrated lake water.

The Okavango Delta is a pristine landlocked wetland located in Southern Africa. In the Okavango Delta, the hydrologic regime is well documented and incredibly interesting. There is a large increase in solute, and DOM concentration, that occurs as you move inward toward the island centers. This DOM has varying properties as you move center (analysis is underway).