Disappearing Lakes: New Data Platform on Permafrost Lakes in the Arctic

The ‘Lost Lakes’ database provides access to information on water area to identify changes in Arctic permafrost landscapes and help local communities respond to these shifts

[Translate to English:] Kürzlich ausgelaufener See — Recently drained lake (Photo: Alfred Wegener Institute / Ingmar Nitze)

Permafrost is a key component of the Arctic’s complex ecosystem: it stores large quantities of carbon over long periods and provides for firm, stable ground. As the ice melts, the ground subsides, creating a depression in which meltwater can collect and, over many years, grows into a lake. While these thermokarst lakes accelerate the thawing of permafrost, they are a vital source of livelihood for local people at the same time. With technical support from North American partners, researchers at the Alfred Wegener Institute have established the ‘Lost Lakes‘ database, which provides key information on the state of Arctic thermokarst lakes in real time, as well as over longer periods. This enables detecting changes in permafrost landscapes as soon as they occur and helps local communities to respond at an early stage.

Thermokarst lakes are typical, highly dynamic features in the relatively flat Arctic and sub-Arctic permafrost regions: they form when ice-rich permafrost thaws; they then drive further thawing forward, thereby making the carbon once frozen in the permafrost accessible to microbes, which convert it into greenhouse gases such as CO₂ and methane. Increasing global warming, however, is also causing the permafrost to thaw to ever greater depths, meaning that entire lakes can suddenly disappear within a matter of hours if the ground beneath them or the banks become unstable and the water finds its way through. From their formation through their continued growth to their disappearance, they change over periods ranging from decades and on to millennia.

[Translate to English:] Kobuk Delta in Nordwest Alaska — Kobuk Delta in Northwest Alaska (Photo: Alfred Wegener Institute / Ingmar Nitze)

There are millions of such thermokarst lakes in the Arctic. “They are of great importance for local communities, as they are often the only source of drinking water,” says Dr Ingmar Nitze of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) in Potsdam. With technical support from the project partners, the permafrost researcher has developed the ‘Lost Lakes’ platform, which uses map views, time-series charts and satellite forecasts to display the water levels of around 4 million Arctic lakes in real time – and thereby identifying those lakes that are currently disappearing. This is not, however, only of scientific interest. For when lakes suddenly dry up, this jeopardises the drinking water supply of Arctic communities, which is already under strain in permafrost regions: the frozen ground, which in some places is several hundred metres thick, prevents groundwater from being readily available, while surface waters can also be heavily contaminated by pollutants, bacteria and industrial waste.

“Local people, who spend a lot of time in this landscape, are usually the first to notice its constant ongoing change,” as Ingmar Nitze relates. With Lost Lakes, they now also have access to real-time scientific data that support these personal observations, help them monitor the wider environment and may also enable them to plan necessary courses of action more effectively. “To make it easier to access, we have developed an interactive dashboard. Using this digital overview, users can examine spatial patterns, long-term trends and current satellite images for the lakes in their region or other areas.”

Lost Lakes shows how lakes in the Arctic have changed markedly since 2016

[Translate to English:] Frisch ausgelaufener Thermokarstsee — Recently drained thermokarst lake (Photo: Alfred Wegener Institute / Ingmar Nitze)

The platform displays data on around 4 million lakes in near real time, as well as showing how they have changed since 2016. Since then, just under 10,000 lakes have lost a sizeable area or even completely disappeared. There are significant seasonal fluctuations. Most of them suddenly drain shortly after the snowmelt and up until the height of summer, between June and early August. Warm temperatures and snowy winters, in particular, destabilise the permafrost, and the excess meltwater can cause lateral breaches along the lake shores, through which all the water suddenly drains away, causing a lake that may have existed for centuries to disappear. An exceptionally large number of lakes disappeared, particularly in the summers of 2018, 2020 and 2022. This was partly facilitated by the extremely warm and snowy winters that preceded them, which prepared the ground for deeper summer thawing and subsequent lateral drainage of lakes later in the summer.

In some cases, very significant regional differences are also in evidence, as lake dynamics depend heavily on factors such as climate, subsoil and the condition and nature of the permafrost itself. “We have a study area in western Alaska, the Seward Peninsula, which has been very severely affected and where many of the largest lakes have disappeared over the last 20 years or so,” as Ingmar Nitze relates. In the winter of 2017/2018, for example, a total of 192 lakes drained completely or partially – almost twice as many as in the previous record years of 2005 and 2006. “North-western Alaska is heavily impacted by changing climate patterns, with new record highs for temperatures and precipitation recorded in recent years. This year, too, we have already observed a few notable lakes that are in the process of disappearing.”

[Translate to English:] Seenreiche Permafrost Landschaft auf der Seward Halbinsel, Alaska. — Seward Peninsula (Photo: Alfred Wegener Institute / Ingmar Nitze)

In order to be able to make reliable statements by way of satellite images as to whether a thermokarst lake is actually draining, the AWI researchers have developed a numerical index calculated from satellite data, which they can use to classify their observations accordingly. For example, it is highly likely that a lake is losing water if it appears significantly smaller than expected in the satellite images, or if its extent drops below the absolute minimum recorded since 2017. “In addition to the water surface area, we have also analysed the multispectral satellite images in such a way that we can draw conclusions about surface water, snow and ice cover, exposed ground and vegetation,” explains Ingmar Nitze. “With Lost Lakes, we can automatically and in near real time determine, for every lake in the Arctic permafrost region, whether sudden or gradual, persistent water losses are merely temporary anomalies or whether they are actually ushering in the permanent disappearance of a lake.”

Permafrost Discovery Gateway and PeTCaT

The development of ‘Lost Lakes’ forms part of the ‘Permafrost Discovery Gateway’, and the ongoing and future analyses will be continued as part of the ‘PeTCaT’ project.

[Translate to English:] Großer Thermokarstsee in Lena Delta, Sibirien. — Large thermokarst lake in the Lena Delta, Siberia (Photo: Alfred Wegener Institute / Ingmar Nitze)

The ‘Permafrost Discovery Gateway’ (PDG) is a freely accessible online platform providing information on permafrost conditions across the Arctic. It offers large spatial datasets and tools that local communities, researchers and the general public can use freely and conveniently. Since 2023, an international group of experts, including the AWI, has been working to develop an AI system for the PDG that will enable the thawing of Arctic permafrost to be investigated even more quickly and effectively. ‘Lost Lakes’ is part of this project, which is funded by Google.org to the tune of US $ 5 million.

Drawing on its expertise in permafrost research, the AWI is leading the ‘Rapid Permafrost Thaw Carbon Trajectories’ (PeTCaT) project. The aim is to fill the gaps in our understanding of rapid thaw processes and to build a novel dataset as a foundation for projections, in order to highlight potential developments and the impact of greenhouse gases released from thawing permafrost. To this end, the AWI is collaborating with researchers from Germany, the USA, Canada, the Netherlands and Sweden. The project is endowed with a US $10 million fund by the non-profit organisation Schmidt Sciences.

Further information

‘LostLakes’ platform
https://lostlakes.arcticdata.io/

Permafrost Discovery Gateway
https://arcticdata.io/catalog/portals/permafrost/Imagery-Viewer

Rapid Permafrost Thaw Carbon Trajectories (PeTCaT)
https://www.petcat.earth/

Article about the platform in ‘The Conversation’ (in English)
https://theconversation.com/disappearing-lakes-and-ai-are-helping-scientists-map-arctic-permafrost-thaw-in-near-real-time-290238