A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Near‐Bed Flow Turbulence Beneath Ice Cover Under Varying Hydrological Conditions: A 9‐Year Field Measurement‐Based Analysis From a Meander Bend
Tekijät: Lintunen, Karoliina; Vilhonen, Essi; Takala, Tuure; Blåfield, Linnea; Kasvi, Elina; Lotsari, Eliisa; Alho, Petteri
Kustantaja: American Geophysical Union (AGU)
Julkaisuvuosi: 2026
Lehti: Water Resources Research
Artikkelin numero: e2025WR042447
Vuosikerta: 62
Numero: 3
ISSN: 0043-1397
eISSN: 1944-7973
DOI: https://doi.org/10.1029/2025WR042447
Julkaisun avoimuus kirjaamishetkellä: Avoimesti saatavilla
Julkaisukanavan avoimuus : Kokonaan avoin julkaisukanava
Verkko-osoite: https://doi.org/10.1029/2025wr042447
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/523436898
Rinnakkaistallenteen lisenssi: CC BY
Rinnakkaistallennetun julkaisun versio: Kustantajan versio
Climate change alters hydrological and ice conditions, but how these changes affect turbulence beneath ice cover has been poorly studied. This study presents a multi-year observational analysis of near-bed turbulence under ice cover in a subarctic meandering river reach. Measurements were obtained using an Acoustic Doppler Current Profiler (ADCP) and an Acoustic Doppler Velocimeter (ADV), which provided flow parameters and enabled the calculation of turbulence variables, together with a camera to capture visual information on bedforms. In the analyses, we considered the effects of water column height, ice thickness, discharge, and riverbed forms on near-bed turbulence. The results show that water column height beneath ice cover is the most consistent factor controlling turbulence because near-bed turbulence generally decreases as the water column height increases. Conditions during ice formation affected the resulting water column height and thus indirectly influenced near-bed turbulence. Turbulence was most pronounced in shallow upstream and inner-bend sections of the meander whereas deeper areas exhibited reduced turbulence. Discharge modulated the ice effect, with low to moderate winter flows amplifying ice's influence on near-bed turbulence whereas higher flows tended to override it. Thicker ice cover was associated with reduced turbulent kinetic energy (TKE) but with increased streamwise and vertical turbulence intensities during low-flow years. These results suggest that ongoing shifts in winter ice regimes and flow seasonality may alter under-ice turbulence, with consequent effects on sediment transport and channel morphodynamics. Uncertainty in comparisons arises from instrument limitations, field conditions, and interannual variability in hydrological regimes.
Ladattava julkaisu This is an electronic reprint of the original article. |  |
Julkaisussa olevat rahoitustiedot:
This study is part of the PhD research project of MSc Lintunen, funded by the doctoral programme in Biology, Geography and Geology (BGG) of the University of Turku Graduate School (UTUGS). This research has been conducted with the support of Digital Waters Flagship (decision no. 359247; 359248), funded by the Research Council of Finland Flagship Programme. The ice-covered flow measurements were initiated under the post-doctoral research project of Dr Lotsari, funded by the Research Council of Finland (ExRIVER: Grant 267345). The work for this paper was also supported financially by other Research Council of Finland funded projects (DefrostingRivers: 338480, 346602, and 359917; HYDRO-RDI-Network: 337394 and 337279; AnthroCliMocs: 355018; International research mobility, to Finland from Russia, Dr. Nikita Tananaev: 333218). In addition, the work was funded by The European Union—NextGenerationEU Recovery instrument (RRF) through Research Council of Finland projects Green-Digi-Basin (347703; 347701) and HYDRO-RI-Platform (346161; 346167). Funding was received from the Maj and Tor Nessling Foundation (ExRIVER, Grants 201300067 and 201500046; Influence of river ice and fluvial processes on river environments now and in the future, Grant 201600042), Maa- ja vesitekniikan tuki ry (MVTT, “Changing northern rivers and their material transport under warming climatic conditions,” Grant 43465), Emil Aaltonen Foundation (“kohdeapuraha” in 2016), and Strategic Research Council at the Academy of Finland (Competence-Based Growth Through Integrated Disruptive Technologies of 3D Digitalization, RobotiCS, Geospatial Information and Image Processing/Computing—Point Cloud Ecosystem, Grant 293389). The Department of Geographical and Historical Studies, University of Eastern Finland, supported the work financially. Funding was also received from the British Society for Geomorphology (research project title “Defrosting sedimentary systems: the impacts on the evolution and material transport of high-latitude rivers” [registered charity number: 1054260]). Open access publishing facilitated by Turun yliopisto, as part of the Wiley - FinELib agreement.
