Dr Aga Nowak

Image of Aga

Email: A.Nowak@sheffield.ac.uk
Room: C5
Tel: +44 (0)114 222 79​73


Aga joined the department in 2008 as an early stage researcher on the NSINK project. She has a training background in physical oceanography (MSc at Uniwersytet Gdański) and in hydrological and biogeochemical processes in polar regions (PhD at The University of Sheffield).

Over the last years Aga has been actively involved in research projects, funded by NERC, NERC-AFI, UNIS, South Georgia government, and Longyearbyen Research Council, that focused on the response of polar regions to climate change.

Her recent collaborations include the British Armed Forces with whom she works on understanding microbial life in the death zone via the Makalu2014 expedition. In late August 2014 she has accepted a position as PDRA at the Department of Geography in Cold Regions Biogeochemistry.


Aga specialises in cold regions hydrology, biogeochemistry and linking the two to climate change. Having a degree in marine chemistry enables her to study the effects of deglaciating catchments on marine environments.

She has six years of experience working in the Arctic during both spring and summer seasons. Apart from her Arctic research she also teaches UNIS (University Center in Svalbard) students about summer and winter glacial - groundwater interactions.

Integrating the above and linking it to microbial ecosystems present on/within/under the ice and supra-/intra-/sub-permafrost is a subject of her ongoing research.

In addition to her work in the Arctic, Aga has also spent two seasons working in the Antarctic Islands (Livingston and South Georgia), where she characterised hydrology and biogeochemistry of subglacial meltwater as well as groundwater and their possible influence on near-shore environments.

Glacial meltwater – groundwater interactions

Glacial meltwater – groundwater interactions

Investigating groundwater discharge, spring 2013

Hydrological and biogeochemical processes

Hydrological and biogeochemical processes in glacial and permafrost environments

The influence of runoff on marine environments

The influence of runoff on marine environments

Cryosphere – biosphere coupling

Cryosphere – biosphere coupling

Fine reactive sediments produced by glacial erosion sustain microbial habitats in subglacial, ice marginal and other sedimentary environments. Therefore, it is not surprising that microbially- mediated rock-water interactions dominate the anionic composition of glacial meltwaters and acquire nutrients with the capacity to fertilise downstream ecosystems. However, those processes are difficult to detect when glacier surface melting strongly reduces the signal to noise ratio found in runoff samples. Therefore, to identify those processes, evaluate microbially mediated production but also to classify microbial communities, we have been sampling subglacial waters and icings from Svalbard’s multiple glaciers during the pre-melt and the end of ablation season. In so doing, we have also developed redox-sensitive, groundwater sampling techniques suitable for air temperatures as low as -30oC. Our results reveal weathering environments characterised by low redox weathering processes (iron and sulphate reduction, methanogenesis) that are barely detectable in summer runoff. We have also found that the icings formed when these springs discharge into the proglacial environment during winter are active ecosystems regardless the season. Furthermore, heterogeneity in microbial communities existing on and within the icings was discovered. Greater abundance of microorganisms was observed in the upper and lowermost parts of the icings, yet not all icings were the same. Major variations in the microbial community structure were therefore found from one icing to another. In some cases a significant autotrophic community were fertilised by high concentrations of iron and ammonium, resulting in the development of distinct microbial mats.


As Aga’s passion is explorations of polar regions, she spends as much time as possible in Svalbard doing exploratory style research. Such an approach resulted in funded projects, multiple collaborations as well as field trips twice a year, on which she teaches UNIS and University of Sheffield students about rapidly changing High Arctic environment.

Aga believes in learning via participation in research projects. Teaching about hydrological and biogeochemical processes while performing fieldwork gives the students appreciation of natural environments and their complexity.

Additionally, she ​uses a wide range of laboratory ​classes that help to understand micro-scale processes, in order to broaden the understanding of ‘the big picture’ in climate change. Therefore, during her classes students gain not only the understanding of the processes occurring in the natural environment, but also the necessary skills needed in a career outside of academia.

GEO154 Environmental Science Level 1 Field Class
GEO244 Earth and Ecosystem Dynamics

GEO6604 Geochemical Techniques in Environmental Analysis
GEO6613 Arctic/Alpine Field Course

With the students in front of Tunabreen, 2011 On Aldegondabreen scoping for new sites for PAC students during summer 2012

  • Hodson A., Nowak A., Marie Sabacka, Anne Jungblut, Francisco Navarro, David Pearce, María Luisa Ávila-Jiménez, Peter Convey, Gonçalo Vieira. In review, Climatically-sensitive transfer of iron to maritime Antarctic ecosystems by surface runoff, Nature Comms
  • Hodson, A., Nowak, A., Christiansen, H. 2015. Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high Arctic fjord. Hydrological Processes
    DOI: 10.1002/hyp.10701
  • Nowak A & Hodson AJ. 2014. On the biogeochemical response of a glacierized High Arctic watershed to climate change: Revealing patterns, processes and heterogeneity among microcatchments. Hydrological Processes.
    DOI: 10.1002/hyp.10263
  • Nowak A & Hodson AJ. 2014. Changes in meltwater chemistry over a 20 year period following a thermal regime switch from polythermal to cold-based glaciation at Austre Brøggerbreen, Svalbard, Polar Research 2014, 33, 22779, http://dx.doi.org/10.3402/polar.v33.22779
  • Hodson, A., Nowak, A., Christiansen, H. 2015. Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high Arctic fjord. Hydrological Processes
    DOI: 10.1002/hyp.10701
  • Nowak A & Hodson AJ. 2013. Hydrological response of a High Arctic catchment to changing climate over the past 35 years; A case study of Bayelva watershed, Svalbard, Polar Research 32, 19691, http://dx.doi.org/10.3402/polar.v32i0.19691
  • Nowak-Zwierz A. 2013. Hydrological and Biogeochemical response of a High-Arctic glacierized catchment to climate change; A long term study from Bayelva watershed; Svalbard. PhD Thesis, The University of Sheffield, Sheffield, UK
  • Hodson AJ, Nowak A & Christiansen H. 2013. The water supply to Longyearbyen: understanding the present system and future uncertainties
  • Nowak A & Hodson A. 2013. Biogeochemistry and microbiology of winter runoff from Svalbard glaciers. ICE: p.18; ISBN: ISSN 0019-1043
  • Nowak-Zwierz A. 2010. Biogeochemistry of meltwater in the High Arctic with an emphasis on N species: A nested catchment approach. AGU Fall Meeting Abstracts