• Benthic dissolved silicon and iron cycling at glaciated Patagonian fjord heads 

      Ng, Hong Chin; Hawkings, Jon R.; Bertrand, Sebastien; Summers, Brent A.; Sieber, Matthias; Conway, Tim M.; Freitas, Felipe S.; Ward, James P.J.; Pryer, Helena V.; Wadham, Jemma Louise; Arndt, Sandra; Hendry, Katharine R. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-18)
      Glacier meltwater supplies silicon (Si) and iron (Fe) sourced from weathered bedrock to downstream ecosystems. However,the extent to which these nutrients reach the ocean is regulated by the nature of the benthic cycling of dissolved Siand Fewithin fjord systems,given the rapid deposition of reactive particulate fractions at fjord heads. Here, we examine the benthic cycling of the two nutrients at ...
    • Catchment characteristics and seasonality control the composition of microbial assemblages exported from three outlet glaciers of the Greenland Ice Sheet 

      Vrbická, Kristýna; Kohler, Tyler J.; Falteisek, Lukáš; Hawkings, Jon R.; Vinšová, Petra; Bulínová, Marie; Lamarche-Gagnon, Guillaume; Hofer, Stefan; Kellerman, Anne M.; Holt, Amy D.; Cameron, Karen Anne; Schön, Martina; Wadham, Jemma Louise; Stibal, Marek (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-29)
      Glacial meltwater drains into proglacial rivers where it interacts with the surrounding landscape, collecting microbial cells as it travels downstream. Characterizing the composition of the resulting microbial assemblages in transport can inform us about intra-annual changes in meltwater flowpaths beneath the glacier as well as hydrological connectivity with proglacial areas. Here, we investigated ...
    • Centre for ice, Cryosphere, Carbon and Climate (iC3)- closing large scale uncertainty in Polar ice sheet impacts on the global carbon cycle 

      Winsborrow, Monica Caroline Mackay; Wadham, Jemma Louise (Conference object; Konferansebidrag, 2023-08)
      Recently funded for 10 years by the Research Council of Norway centres of excellence scheme, iC3 aims to fill a major research gap in polar science by quantifying the future impact of ice sheet change on Earth’s carbon cycle over policy-relevant timescales. It will achieve this by uniting complementary expertise at UiT The Arctic University of Norway, the Norwegian Polar Institute and a network of ...
    • Centre for Ice, Cryosphere, Carbon and Climate (iC3). Closing large-scale uncertainty in Polar ice sheet impacts on the global carbon cycle 

      Wadham, Jemma Louise; Winsborrow, Monica Caroline Mackay; Souster, Terri Ann (Conference object; Konferansebidrag, 2023-09)
    • Factors controlling the net ecosystem production of cryoconite on Western Himalayan glaciers 

      Shamurailatpam, Monica S.; Telling, Jon; Wadham, Jemma Louise; Ramanathan, A. L.; Yates, Christopher A.; Raju, N. Janardhana (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-07)
      In situ experiments were conducted to determine the net ecosystem production (NEP) in cryoconite holes from the surface of two glaciers (Patsio glacier and Chhota Shigri glacier) in the Western Himalaya during the melt season from August to September 2019. The study aimed to gain an insight into the factors controlling microbial activity on glacier surfaces in this region. A wide range of parameters, ...
    • Physical weathering by glaciers enhances silicon mobilisation and isotopic fractionation 

      Hatton, J.E.; Hendry, K.R.; Hawkings, J.R.; Wadham, Jemma Louise; Benning, L.G.; Blukis, R.; Roddatis, V.; Ng, H.C.; Wang, T. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-06)
      Glacial meltwaters export substantial quantities of dissolved and dissolvable amorphous silicon (DSi and ASi), providing an essential nutrient for downstream diatoms. Evidence suggests that glacially exported DSi is isotopically light compared to DSi in non-glaciated rivers. However, the isotopic fractionation mechanisms are not well constrained, indicating an important gap in our understanding ...
    • Rapid development and persistence of efficient subglacial drainage under 900 m-thick ice in Greenland 

      Chandler, David Matthew; Wadham, Jemma Louise; Nienow, Peter W.; Doyle, Samuel H.; Tedstone, Andrew J.; Telling, Jon; Hawkings, Jonathan R.; Alcock, Jonathan; Linhoff, Benjamin; Hubbard, Alun Lloyd (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-11)
      Intensive study of the Greenland Ice Sheet's (GrIS) subglacial drainage has been motivated by its importance for ice dynamics and for nutrient/sediment export to coastal ecosystems. This has revealed consistent seasonal development of efficient subglacial drainage in the lower ablation area. While some hydrological models show qualitative agreement with field data, conflicting evidence (both field- ...
    • Seasonal Changes in Dissolved Organic Matter Composition in a Patagonian Fjord Affected by Glacier Melt Inputs 

      Marshall, Matthew G.; Kellerman, Anne M.; Wadham, Jemma Louise; Hawkings, Jon R.; Daneri, Giovanni; Torres, Rodrigo; Pryer, Helena V.; Beaton, Alexander; Ng, Hong Chin; Urra, Alejandra; Robinson, Laura F.; Spencer, Robert G.M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-09)
      Biogeochemical processes in fjords are likely affected by changes in surrounding glacier cover but very little is known about how meltwater directly influences dissolved organic matter (DOM) in fjords. Moreover, the data available are restricted to a handful of northern hemisphere sites. Here we analyze seasonal and spatial variation in dissolved organic carbon (DOC) concentration and DOM composition ...
    • Using thermal UAV imagery to model distributed debris thicknesses and sub-debris melt rates on debris-covered glaciers 

      Bisset, Rosie R.; Nienow, Peter W.; Goldberg, Daniel N.; Wigmore, Oliver; Loayza-Muro, Raúl A.; Wadham, Jemma Louise; Macdonald, Moya L.; Bingham, Robert G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-14)
      Supraglacial debris cover regulates the melt rates of many glaciers in mountainous regions around the world, thereby modifying the availability and quality of downstream water resources. However, the influence of supraglacial debris is often poorly represented within glaciological models, due to the absence of a technique to provide high-precision, spatially continuous measurements of debris thickness. ...