Emmy Noether Young Investigator Group SNOWflAke

Snow rules!

Snow pit on Antarctic sea ice with marked identified layers within the vertical snow profile. (Photo: Stefanie Arndt/ Alfred-Wegener-Institut)

SNOWflAke (Learning from local snow properties for large-scale Antarctic ice pack volume) aims to investigate how the snow cover on Antarctic sea ice responds to changing atmospheric conditions, affecting the sea ice mass balance by inducing snow-albedo feedbacks that accelerate sea ice melt and retreat.

Combining observations, model development and evaluation, this research will significantly improve our process understanding of Antarctic sea ice in the Southern Ocean climate system – from today’s perspective and for future warming climate scenarios.

Background

Snow depth on sea ice is an essential climate variable, as it dominates the energy and momentum exchanges across the atmosphere-ice-ocean interfaces and actively contributes to the sea ice mass balance. The Antarctic sea ice is characterized by a year-round snow cover preventing surface melt in summer, and amplifying sea ice growth through extensive snow-to-ice conversion processes. The lack of knowledge on both snow depth and the complex seasonal stratigraphy causes substantial uncertainties in large-scale data products from satellite remote sensing. Also, the accurate representation of these small-scale processes within the snowpack in numerical models, in particular in climate models remains a major challenge. This leads to essential uncertainties in the Antarctic sea ice energy and mass budgets as outlined in the IPCC “Special Report on the Ocean and Cryosphere in a Changing Climate”.

Mission

Within the project, we will therefore test the hypothesis that seasonal variations of snowpack properties on Antarctic sea ice are sensitive indicators for changing atmospheric forcing as they could trigger snow-albedo feedbacks that accelerate sea ice melting and retreat. This hypothesis is important as snow has so far contributed to a positive Antarctic sea ice mass balance due to widespread snow-to-ice conversion processes. The present climate warming might reverse this evolution and lead to increased surface melting, as currently prevalent for Arctic sea ice feedbacks for the Earths’ climate.

Cross-scale process understanding in the vertical snow column

Quantification of the temporal evolution of internal snow properties and governing processes in different Antarctic sea ice regimes
Cross-scale process understanding in the vertical snow column by using snow models

Antarctic sea ice mass budget

Quantification of the influence of the snowpack and its internal properties on the Antarctic sea ice mass budget
Reduction of uncertainties in Antarctic sea ice thickness from satellite remote sensing data products

Antarctic sea ice variability

This work is carried out in the framework of the DFG SPP 1158 project fAntasie (A friend or foe for the future Antarctic sea ice mass budget?).

fAntasie aims to better understand the temporal and spatial variability of the different components of the Antarctic sea ice mass budget and its interaction with the atmosphere and ocean.

(Antarctic) Climate change

Improved snow process formulations in climate models
Investigation of the impact of changing atmospheric and oceanic processes on the evolution of Antarctic sea ice and its role within the climate system

From pole to pole

Cross-pole process understanding of seasonal snow properties
Investigation of occurrence of characteristic Antarctic snow processes and properties on Arctic sea ice, and vice versa

Schematic overview of processes and methods studied on respective spatial scales within SNOWflAke. Blue arrows indicate the marked atmospheric and oceanic circulation patterns. The basin-scale panel gives an additional overview of all sea ice and snow stations sampled during expeditions of the German ice breaker RV Polarstern since 1997, which will be used within SNOWflAke — Schematic overview of processes and methods studied on respective spatial scales within SNOWflAke. (Graphic: Stefanie Arndt/ Alfred-Wegener-Institut)

Team

Prof. Dr. Stefanie Arndt

Group leader

Personal website

Dr. Nina Maaß

Postdoc

Personal website

Daria Paul

PhD student

Personal website

Anton Birkedal

PhD student

Personal website

Sacha van der Vleuten

PhD student

Personal website

Students

Zubair Jalal

Master student (University of Hamburg)

Dominik Austen

Master student (University of Hamburg)

Associate members

Dr. Andreas Wernecke

Postdoc (University of Hamburg)

Personal website

Alumni

Kirsten Schulze

Master student (University of Hamburg)

Thesis title | Evaluation of Snow Depth Retrievals from Differences in ICESat-2 and CryoSat-2 Freeboards Using In-Situ Measurements in the Weddell Sea

Loana Grom

Master student (University of Hamburg)

Thesis title | Sensitivity of snow and ice properties to atmospheric influences in recent years with low sea ice extent in the Weddell Sea, Antarctic

Links and cooperations

Enporer penguins on sea ice in front of Polarstern.

Sea Ice Physics

Our home section at AWI

Reflection of the ice shelf edge in the adjacent ocean waters.

Institute of Oceanography

Our home institute at the University of Hamburg

Emmy Noether Programme

Emmy Noether Programme of the DFG

DFG SPP 1158

DFG priority program “Antarctic Research with comparative investigations in the Arctic ice areas” (SPP1158)

AWI Young Investigator Groups

Young Investigator Groups at AWI

Group of young penguins on the sea ice. — Penguin youngsters (Photo: Stefanie Arndt/ Alfred-Wegener-Institut)

Fast ice program

Fast ice program at Neumayer Station

FlAke News

ESA Living Planet Symposium | LPS2025

June 2025 | Vienna, Austria | We presented our recent work on observational and remote sensing data of snow on Antarctic sea ice, as well as on improving snow models, in various sessions at the LPS2025.

UN Climate Change Conference | COP29

November 2024 | Baku, Azerbaijan | At the UN Climate Change Conference, Stefanie Arndt provided insights into the current development of sea ice - with a particular focus on the drastic changes in the Southern Ocean.

PS146 | Expedition to the Weddell Sea

December 2024 to March 2025 | RV Polarstern | Stefanie Arndt and Daria Paul joined expedition PS146 aboard RV Polarstern to study the physical and biological properties of the sea ice and its snow cover in the Weddell Sea. …

AWI Science Week 2024

November 2024 | Bremerhaven | Nina Maaß, Daria Paul and Anton Birkedal presented the current status of their postdoc and doctoral projects at the AWI Science Week in Bremerhaven.

Publications

2025

Mellat, M., Macfarlane, A. R., Brunello, C. F., Werner, M., Schneebeli, M., Dadic, R., Arndt, S., Mustonen, K.-R., Welker, J. M., Divine, D. V., and Meyer, H.: Arctic surface snow interactions with the atmosphere: Spatio-temporal isotopic variability during the MOSAiC expedition, Elementa: Science of the Anthropocene, 13, 10.1525/elementa.2025.00028, 2025.

Arndt, S., Webster, M., Sturm, M., and Massom, R. A.: Snow on sea ice and how it varies through the seasons, in: Sea Ice, D.N. Thomas (Ed.), 41-112, 10.1002/9781394213764.ch02, 2025.

Anhaus, P., Katlein, C., Arndt, S., Krampe, D., Lange, B. A., Matero, I., Salganik, E., and Nicolaus, M.: Under-ice environment observations from a remotely operated vehicle during the MOSAiC expedition, Scientific Data, 12, 944, 10.1038/s41597-025-05223-1, 2025.

2024

Xu, R., Zhao, C., Arndt, S., and Haas, C.: Dual-frequency radar observations of snowmelt processes on Antarctic perennial sea ice by CFOSCAT and ASCAT, The Cryosphere, 18, 5769-5788, 10.5194/tc-18-5769-2024, 2024.

Neudert, M., Arndt, S., Hendricks, S., Hoppmann, M., Schulze, M., and Haas, C.: Improved sub-ice platelet layer mapping with multi-frequency EM induction sounding, Journal of Applied Geophysics, 230, 105540, https://doi.org/10.1016/j.jappgeo.2024.105540, 2024.

Joshi, M., Mestas-Nuñez, A. M., Ackley, S. F., Arndt, S., Macdonald, G. J., and Haas, C.: Seasonal and Interannual Variations in Sea Ice Thickness in the Weddell Sea, Antarctica (2019–2022) Using ICESat-2, Remote Sensing, 16, 3909, https://doi.org/10.3390/rs16203909, 2024.

Zhou, L., Stroeve, J., Nandan, V., Willatt, R., Xu, S., Zhu, W., Kacimi, S., Arndt, S., and Yang, Z.: Quantifying the influence of snow over sea ice morphology on L-band passive microwave satellite observations in the Southern Ocean, The Cryosphere, 18, 4399-4434, https://tc.copernicus.org/articles/18/4399/2024/, 2024.

Wernecke, A., Notz, D., Kern, S., and Lavergne, T.: Estimating the uncertainty of sea-ice area and sea-ice extent from satellite retrievals, The Cryosphere, 18, 2473-2486, https://tc.copernicus.org/articles/18/2473/2024/, 2024.

Arndt, S., Maaß, N., Rossmann, L., and Nicolaus, M.: From snow accumulation to snow depth distributions by quantifying meteoric ice fractions in the Weddell Sea, The Cryosphere, 18, 2001–2015, https://doi.org/10.5194/tc-18-2001-2024, 2024.

Mellat, M., Brunello, C. F., Werner, M., Bauch, D., Damm, E., Angelopoulos, M., Nomura, D., Welker, J. M., Schneebeli, M., Granskog, M. A., Hoerhold, M., Macfarlane, A. R., Arndt, S., and Meyer, H.: Isotopic signatures of snow, sea ice, and surface seawater in the central Arctic Ocean during the MOSAiC expedition, Elementa: Science of the Anthropocene, 12, https://doi.org/10.1525/elementa.2023.00078, 2024.

Most recent publication

Snow depth distribution in the Weddell Sea

Arndt, S. et al. (2024): From snow accumulation to snow depth distributions by quantifying meteoric ice fractions in the Weddell Sea