Resolute Bay is part of the Qikigtaaluk Region at the northern end of Canada’s Northwest passage. One of the coldest inhabited places on Earth, it is also the stunning location of recent fieldwork involving CPOM scientists.

In April 2025 the all-female field team of polar scientists from UCL, including Julienne Stroeve, Rosemary Willatt, Carmen Nab and Alicia Fallows, with an airborne team led by Christian Haas from AWI, visited Resolute Bay to investigate the use of Ku- and Ka-band frequency radar and different polarisations on ice and snow.

Watch the team in action in this video case study.

What is KuKa?

KuKa is a dual-frequency radar operating at Ku-band (12-18 GHz) and Ka-band (30-40 GHz) frequencies.

KuKa radar can work in two ways; estimating the distance from the sensor to a surface looking straight down (using Altimeter mode); and also when looking at an incidence angle (using Scatterometer Mode). It can collect information about the polarisation of the waves, which is referred to as ‘Polarimetric Capability’ (You can find out more about this in this paper by Stroeve et al.) Scientists have found that polarisation can help to determine snow depth on Arctic and Antarctic sea ice, which could also help with estimation of sea ice thickness.

The team tested KuKa radar at two sea ice locations, on tundra, and on the frozen freshwater Resolute Lake, towing the KuKa radar on a qamutiik (traditional Inuit sled) at all four sites.

A Magnaprobe was used to determine the snow depth at many points along the same track as the KuKa was tested. A SnowMicroPen (SMP), was used to gain information on the penetration resistance of the snow and build understanding of the snowpack formation.

The Magnaprobe is a rod-like tool used in snow research which is pushed into the snow until it encounters resistance at the ice surface, thereby measuring the snow depth. A SnowMicroPen (SMP) is a device which estimates the snow structure, strength and density, by using a sensor to measure the penetration force in high resolution at intervals, while being forced through the snow.

The team dug snow pits to help identify the snow depth, measure temperature and salinity throughout the snowpack, and to understand physical properties of the snow. They also drilled at several locations, to take measurements of the sea ice thickness and lake ice thickness.

A broadband electromagnetic sensor (GEM) was used to estimate the total snow and ice thickness, and a drone and terrestrial laser scanner were used to create a 3D profile of the snow surface roughness and for images.

The team could then compare the data they gained from the Kuka device, against the measurements they took manually at the same locations.

This field campaign helps build a better understanding of how snow and ice properties affect radar signals, and retrieval of snow and ice thickness, therefore providing insights for future satellite missions such as the European Space Agency’s (ESA) upcoming CRISTAL space mission.

The concept of the CRISTAL mission is to combine Ku- and Ka-band data for simultaneous snow and ice freeboard measurements. A new technique using polarimetric information, discovered using KuKa, is also under development. This involves analysing how the electromagnetic waves scatter off a surface, which helps scientists to distinguish between the differing surfaces (ice, water or snow) in more detail.

Why is this important?

Field campaigns like these are crucial in understanding how Kuka radar can be used to provide increasingly accurate measurements of the Earth’s ice.

These missions provide information on the Earth system, including the polar regions which we use to assess ice mass balance, associated sea level rise as well as gain a clearer understanding of how global weather patterns are affected by melting ice. This scientific understanding is vital is we are to live and thrive in a changing climate.

Who funded this research?

This field campaign was part of the NERC DEFIANT project. It received funding from the European Union’s Horizon 2020 research and innovation programme via project CRiceS. This research was also supported by the Polar Continental Shelf Program. ESA NEOMI grant 4000139243/22/NL/SD supports development of the polarimetric altimetry concept.

Special Thanks

Thank you to local guide and bear guard, Sheldon, for his expert knowledge and for keeping the team safe on this fieldwork.

Glossary of terms:

Freeboard – the vertical distance between sea level and the top of the ice or snow.
A broadband EM sensor (GEM) – a geophysical electromagnetic induction sensor.
Site transects – the path (or line) along which the team recorded their observations and measurements.
Salinity – the amount of dissolved salt in the water.
Magnaprobe – a rod-like tool used in snow research which is pushed into the snow until it encounters resistance, thereby measuring the snow depth.
SnowMicroPen (SMP) – a device which measures measures the snow structure, strength and density, by using a sensor to measure the penetration force in high resolution at intervals, while being forced through the snow.
KuKa – a dual-frequency radar operating at Ku-band (12-18 GHz) and Ka-band (30-40 GHz) frequencies. KuKa radar can work in two ways; estimating the distance from the sensor to a surface (using Altimeter mode); and also measuring more uneven or rough surfaces (using Scatterometer Mode).
Polarimetric Capability – The ability of KuKa to measure how the electromagnetic waves scatter off a surface, which helps scientists to distinguish between the differing surfaces (ice, water or snow) in more detail.
NERC – Natural Environment Research Council
DEFIANT – Research Programme, led by BAS and funded by NERC – Drivers and Effects of Fluctuations in sea Ice in the ANTarctic. Read more.

Key Publications Relating to the topic

• Stroeve et al. (2020)
• Stroeve et al. (2020)
• Nandan et al. (2023)
• Willatt et al. (2023)
• Willatt et al. (2025)

Ice Sheets and Sea Level Rise – what we know and why it matters

Mean sea level has risen by 11.5cm since the early 1990s, due to the melting of land ice, changes in land-water storage (when water originally contained on land mass moves into the oceans) and thermal expansion of the oceans (water expanding as it warms).

Sea level rise is already affecting the UK, increasing coastal erosion and flooding, in particular during storm surges. This puts coastal communities, habitats and key infrastructure, such as power stations, at risk.

Monitoring the Ice Sheets

The Earth’s colossal ice sheets, in Greenland and Antarctica, are major contributors to sea level rise.

Thanks to advancements in Earth Observation satellite missions, technologies and computer modelling capabilities, we can now monitor these ice sheets accurately and project future scenarios. However, significant uncertainties remain around how the ice sheets are going to behave in the coming decades.

Insights from the Experts

In the ‘Sea Level Uncertainties From the Ice Sheets’ webinar (16 July) organised by the UK National Climate Science Partnership, Dr Inès Otosaka (CPOM) and Dr Rosie Williams from the British Antarctic Survey (BAS) shared key findings.

Ice sheets are melting, and this is accelerating

Dr Otosaka explained:

• The Ice Sheet Mass Balance Inter-Comparison Exercise (IMBIE) led by CPOM has been utilising data from satellite missions to monitor the mass balance of the ice sheets and their contribution to sea levels.
• The Greenland and Antarctic ice sheets are contributing a quarter of all sea level rise and are driving its acceleration. Since 1979, ice sheets have added 3.2cm to sea level rise and the pace of loss is increasing.
• Greenland is melting faster than Antarctica now, but Antarctica is seeing mass loss in the West.
• Ice loss is tracking at the upper end of IPCC projections.

Why so much uncertainty?

Dr Williams explained that:

• Different models and climate forcings produce varying results.
• Subsurface processes such as under-ice melting are hard to observe from space.
• Smaller scale processes can have large impacts, for instance calving and fracturing of the ice sheet as they are taking place at inaccessible places and no laws around general calving currently exist.
• Instability processes such as Marine Ice Cliff Instability (MICI) are still not fully understood.

Rosie went on to explain some of the High Impact Low Likelihood (HILL) scenarios produced by the IPCC.

• The contribution of Antarctic ice melt will dominate all other sources of sea level rise in the coming years due to Marine Ice Cliff Instability.
• By 2100 we could see almost 2m of sea level rise.

The cost of inaction

The UK, and many other countries around the world, are vulnerable to the impacts of sea level rise, so we need to understand better what’s coming and when.

If we fail to adapt appropriately to sea level rise by 2050 the cost could exceed £24 billion a year, in comparison to the projected cost of £3.41 billion/year for ideal adaptation (Rising et al., 2022).

It is vital we understand the potential scenarios and can recognise when we are confronted with one. This is why there is an urgent need to continue to monitor and model the ice sheets.

What we can do

Despite the risks, there is still hope. The worst-case scenarios are not inevitable. Research conducted by the TerraFIRMA team using the UK Earth System Model (UKESM) simulations shows that every degree of warming matters when it comes to sea level rise.

If we act now to reduce emissions, boost our capabilities in monitoring and modelling the ice, and develop Early Warning Systems, we can still aim to thrive in a changing climate.

Watch the full presentation to find out more…