Implications of river intrusion and convective mixing on the spatial and temporal variability of under-ice CO2
| Autor: | Carsten J. Schubert, Hilmar Hofmann, Natacha Pasche, Damien Bouffard, Petr A. Lozovik, Sebastian Sobek |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
010504 meteorology & atmospheric sciences Aquatic Science Spatial distribution Atmospheric sciences under-ice 01 natural sciences chemistry.chemical_compound Intrusion humic lake ddc:570 Convective mixing river intrusion GeneralLiterature_REFERENCE(e.g. dictionaries encyclopedias glossaries) 0105 earth and related environmental sciences Water Science and Technology spatial distribution 010604 marine biology & hydrobiology carbon dioxide carbon dioxide convective mixing humic lake humic lake river intrusion spatial distribution under-ice Miljövetenskap chemistry 13. Climate action Carbon dioxide convective mixing Environmental science Environmental Sciences |
| Popis: | Ice-covered periods might significantly contribute to lake emissions at ice-melt, yet a comprehensive understanding of under-ice carbon dioxide (CO2) dynamics is still lacking. This study investigated the processes driving spatiotemporal patterns of under-ice CO2 in large Lake Onego. In March 2015 and 2016, under-ice CO2, dissolved inorganic carbon (DIC), and dissolved organic carbon (DOC) distributions were measured along a river to an open-lake transect. CO2 decreased from 120/129 μmol L−1 in the river to 51/98 μmol L−1 in the bay, and 34/36 μmol L−1 in the open lake, while DOC decreased from 1.18/1.55 mmol L−1 in the river to 0.67/1.04 mmol L−1 in the bay in 2015 and 2016, respectively. These decreases in concentrations with increasing distance from the river mouth indicate that river discharge modulates spatial patterns of under-ice CO2. The variability between the 2 years was mainly driven by river discharge and ice transparency affecting the extent of under-ice convection. Higher discharge during winter 2016 resulted in higher CO2 concentrations in the bay. By contrast, intensive under-ice convection led to lower, more homogeneously distributed CO2 in 2015. In conclusion, the river-to-bay transition zone is characterized by strong CO2 variability and is therefore an important zone to consider when assessing the CO2 budget of large lakes. |
| Databáze: | OpenAIRE |
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