Journal
LIMNOLOGY AND OCEANOGRAPHY
Volume 53, Issue 6, Pages 2439-2450Publisher
WILEY
DOI: 10.4319/lo.2008.53.6.2439
Keywords
-
Categories
Funding
- National Science Foundation [OPP-432595, OPP-0237335, OPP-0440943, OPP-0631494, EAR-0525567, OPP-0636828]
- Office of Polar Programs (OPP)
- Directorate For Geosciences [1041742, 0832755] Funding Source: National Science Foundation
Ask authors/readers for more resources
The east lobe of Lake Bonney, a permanently ice-covered lake in the McMurdo Dry Valleys, Antarctica, has a mid-depth maximum N2O concentration of 43.3 mu mol N L-1 (>700,000% saturation with respect to air), representing one of the highest concentrations reported for a natural aquatic system. delta N-15 and delta O-18 measurements indicate that this is the most isotopically depleted N2O yet observed in a natural environment (minimum delta N-15-N2O of 279.6% vs. air-N-2; minimum delta O-18-N2O of 24.7% vs. Vienna standard mean ocean water), providing new end points for these parameters in natural systems. The extremely depleted nitrogen and oxygen isotopes, together with nitrogen isotopic isomer data for N2O, imply that most of the N2O was produced via incomplete nitrification and has undergone virtually no subsequent consumption. However, molecular evidence provides little support for metabolically active nitrifying populations at depths where the maximal N2O concentrations occur and contemporary biogeochemical reactions cannot explain the extreme excesses of N2O in Lake Bonney. The gas appears to be a legacy of past biogeochemical conditions within the lake, and in the absence of a significant sink and the presence of a highly stable water column, gradients in N2O produced by past microbial activity could persist in the cold saline waters of Lake Bonney for >10(4) years.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available