Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1002/jpln.200800278 |
| Title (Primary) | Spatial and temporal variability of dissolved nitrous oxide in near-surface groundwater and bubble-mediated mass transfer to the unsaturated zone |
| Author | Geistlinger, H.; Jia, R.; Eisermann, D.; Stange, C.F. |
| Source Titel | Journal of Plant Nutrition and Soil Science |
| Year | 2010 |
| Department | BOPHY |
| Volume | 173 |
| Issue | 4 |
| Page From | 601 |
| Page To | 609 |
| Language | englisch |
| Keywords | greenhouse gases; indirect emission; mass transfer; gas bubbles; groundwater fluctuation |
| Abstract | Understanding spatial and temporal variability of dissolved nitrous oxide (N2O) is essential to process understanding of N2O emissions from near-surface groundwater to the unsaturated zone and to the atmosphere. We propose a conceptual model of bubble-mediated mass transfer within the exchange zone defined by the range of groundwater fluctuations. Based on this model, we discuss our experimental data collected over a period of 2 years from of a small-scale test site (6.5 m × 2.5 m × 5 m, 20 observation wells), where we measured the dissolved gases N2O and O2 at five different depths ( 0.1, 0.5, 0.8, 1.5, and 2.5 m below groundwater level). We show by visualization of the spatially interpolated data and by descriptive statistics that the N2O concentration of near-surface groundwater exhibits a significant anticorrelation to O2 concentration, a spatial coefficient of variation up to 260%, and a spatial-correlation range at the meter-scale. The temporal variation of the spatially averaged data is correlated to the temporal variation of the averaged groundwater level. The implications of high spatial and temporal variability on gradient-based flux models like the steady state-flat interface model usually used in literature are discussed. Our main conclusion is that both the steady-state assumption and the flat-interface model are far from being realistic, because of (1) the highly transient behavior of the exchange zone and (2) the oversimplification of the gas-water interface that underestimates mass transfer by order of magnitudes compared to bubble-mediated mass transfer. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=9987 |
| Geistlinger, H., Jia, R., Eisermann, D., Stange, C.F. (2010): Spatial and temporal variability of dissolved nitrous oxide in near-surface groundwater and bubble-mediated mass transfer to the unsaturated zone J. Plant Nutr. Soil Sci. 173 (4), 601 - 609 10.1002/jpln.200800278 |
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