Channel Network Control on Seasonal Lake Area Dynamics in Arctic Deltas
| Autor: | Joel C. Rowland, Anastasia Piliouras, Efi Foufoula-Georgiou, Lawrence Vulis, Alejandro Tejedor, Jon Schwenk |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Biogeochemical cycle
Channel network 010504 meteorology & atmospheric sciences Permafrost 010502 geochemistry & geophysics Biogeosciences 01 natural sciences Active Layer remote sensing Rivers Evapotranspiration lakes Research Letter Meteorology & Atmospheric Sciences River Channels Permafrost Cryosphere and High‐latitude Processes 0105 earth and related environmental sciences Shrinkage Large Bodies of Water (E.g. Lakes and Inland Seas) Riparian Systems Vegetation Research Letters Lakes Geophysics Arctic Greenhouse gas arctic hydrology General Earth and Planetary Sciences Environmental science arctic deltas Physical geography Other Geographic Location Hydrology Cryosphere Natural Hazards permafrost arctic deltas permafrost remote sensing lakes arctic hydrology |
| Zdroj: | Geophysical Research Letters Geophysical research letters, vol 47, iss 7 |
| ISSN: | 1944-8007 0094-8276 |
| Popis: | The abundant lakes dotting arctic deltas are hotspots of methane emissions and biogeochemical activity, but seasonal variability in lake extents introduces uncertainty in estimates of lacustrine carbon emissions, typically performed at annual or longer time scales. To characterize variability in lake extents, we analyzed summertime lake area loss (i.e., shrinkage) on two deltas over the past 20 years, using Landsat‐derived water masks. We find that monthly shrinkage rates have a pronounced structured variability around the channel network with the shrinkage rate systematically decreasing farther away from the channels. This pattern of shrinkage is predominantly attributed to a deeper active layer enhancing near‐surface connectivity and storage and greater vegetation density closer to the channels leading to increased evapotranspiration rates. This shrinkage signal, easily extracted from remote sensing observations, may offer the means to constrain estimates of lacustrine methane emissions and to develop process‐based estimates of depth to permafrost on arctic deltas. Key Points Summertime lake shrinkage in arctic deltas is highly structured around the channel networkHigher shrinkage rates closer to channels are attributed to enhanced near‐surface flow and storage as well as greater vegetation densityLake methane emission estimates on arctic deltas should account for spatially and seasonally variable lake extents to reduce uncertainty |
| Databáze: | OpenAIRE |
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