The Cotton Glacier project is made possible by a grant from the National Science Foundation to Drs. Foreman, McKnight and Chin.
Dissolved organic matter (DOM) comprises a significant pool of detrital organic carbon on the planet that readily dwarfs the amount present in living aquatic organisms. It is an important component of the global carbon cycle and provides energy for microbial activity; yet its properties and reactivity are not well defined.
Much of the global carbon pool is composed of predominantly recalcitrant organic matter derived from microorganisms that has been extensively worked over by microbial activity and/or humification. It has not been possible to unambiguously observe the formation of autochthonous DOM in a natural environment, until now. The Cotton Glacier supraglacial stream system provides us with a unique laboratory to study this evolution.
Our interdisciplinary team studies the biogeochemistry of the Cotton
Glacier system and this progenitor DOM. During two field seasons (2009-10 and 2010-11) we have isolated the DOM from the system using a variety of chemical techniques to determine how the material changes. This material is then analyzed at the molecular level using state−of−the−art spectroscopy including NMR, electrospray ionization Fourier Transform Ion Cyclotron Resonance mass spectrometry, and fluorescence spectroscopy. The physical and geochemical properites of the site have been measured, and we are currently characterizing the the microbial community composition using clone libraries and 454 pyrosequencing.
By focusing on the chemical composition of the DOM as it shifts from precursor material to the more humified fractions we will be able to relate this transition to environmental site factors, bioavailability, community composition and microbial growth efficiency.
Check out a pdf poster of our research by clicking here, and pdf of a powerpoint presentation showing images of the team at work by clicking here.
Want to follow along with the Cotton Glacier team in the field? Check out the archived blog postings from our Polar Trec teacher in 2009-10.
Polar Trec teacher, Sarah Diers, came down to Antarctica with us in 2009-10. Sarah posted daily journal entries, interviews with scientists and incredible images. If you would like to follow along, click here, or go to http://www.polartrec.com/dissolved-organic-matter-in-antarctica