On thin ice in the arctic

Interview with Vishnu Nandan, polar researcher and lead author of a study report that suggests that Arctic sea ice is melting faster than previously estimated by satellite data.

Published : Jan 31, 2018 12:30 IST

The pristine icy cold desert at Dease Strait, Cambridge Bay, Nunavut, Canadian Arctic (69° North). This photo was taken on April 2, 2017.

The pristine icy cold desert at Dease Strait, Cambridge Bay, Nunavut, Canadian Arctic (69° North). This photo was taken on April 2, 2017.

IN October 2017, the results of a field study on Arctic sea ice, often considered a drab subject, received worldwide attention, especially in the media and among international ice scientists. The study by the Cryosphere Climate Research Group at the University of Calgary, Canada, found that satellite measurements of seasonal sea ice that formed over the Arctic every year were likely to be incorrect by a substantial degree. In a paper published in the academic journal Geophysical Research Letters , the researchers said the estimates so far failed to take into account the amount of salt in the layers of snow over the ice. The presence of salt distorted satellite readings and, as a result, scientists overestimated the thickness of Arctic sea ice.

They found that sea ice in the Arctic was much thinner than estimated and declining rapidly and that it could become completely ice-free during summer even earlier than predicted by popular scientific models. Fast-thinning sea ice in the Arctic Ocean could radically alter global weather patterns; increase the frequency of extreme weather events all over the world; bring about drastic changes in the Arctic ecosystem, its food chain and the life of indigenous communities; and also pose a threat to the survival of animals such as polar bears, Arctic seals and walruses.

The lead author of the paper is Vishnu Nandan, a young passionate researcher from India who has been conducting studies on microwave remote sensing of snow-covered Antarctic and Arctic sea ice. An early-career researcher with several peer-reviewed international publications, Vishnu Nandan has made several field expeditions to both the Arctic and Antarctic sea ice and ice shelves. Before joining the University of Calgary, he was a research associate at the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Germany, where he developed advanced feature detection techniques from radar satellite data for Antarctic Ice Shelves. He did his MSc in Earth Observation Sciences with a first rank from the prestigious ITC Enschede, the Netherlands (now known as The International Institute for Geo-Information Science and Earth Observation).

In this interview to Frontline , Vishnu Nandan speaks about the findings of his group’s (ongoing) studies on Arctic sea ice and their implications; the striking effects of climate change already visible in the Arctic; the consequences of ice-free summers there; the new economic opportunities it is generating and the concerns that it will bring about; the impact of modernity on indigenous communities of the Arctic; the threats faced by the Arctic’s iconic animals and plants, geography and climate; and the sheer thrills and hardships of working in one of the most hostile places on the earth. Excerpts from the interview:

What is the state of Arctic sea ice today because of climate change?

There is no sun in the Arctic during the winter season and so, because of the cold atmosphere, the ocean freezes and forms what we call “sea ice”. Sea ice is highly saline and snow accumulates on top of this salty ice. As spring arrives, the sun comes out and the snow on top of the sea ice starts melting. This is followed by the melting of the ice. This is an annual cycle.

However, what happens nowadays as a result of climate change caused by anthropogenic activities and natural variability is that the ocean freezes late and melts earlier. This is because as the ice cover melts quickly, the ocean gets exposed to sunlight for a longer period. This causes enhanced warming of the Arctic Ocean, which in turn increases the temperature of mid-latitude oceans such as the Indian Ocean, the Pacific Ocean and the Atlantic Ocean. When the ocean gets warmer, it influences global weather patterns, triggering destructive tropical cyclones, affecting the timing of the Asian monsoon season, intensifying heat in coastal areas and so on.

What is your study all about and why has it generated so much interest?

As I said, seasonal sea ice is very salty. When snow falls on top of sea ice, it will absorb some amount of salt and the snow cover also becomes partially or completely salty. For the past 10 years, the European radar satellite called CryoSat-2 has been measuring the thickness of sea ice all over the Arctic. The consensus was that CryoSat-2 was providing us with right estimates of the thickness of Arctic sea ice. However, that may not be true.

What our study has proved is that because of the presence of this salty snow on top of sea ice, the radar signals originating from the CryoSat-2 satellite fail to penetrate through the whole snow cover. It means that the thickness of sea ice which CryoSat-2 has been estimating may have been an overestimation, likely by up to 25 per cent. Current climate models predict that summer sea ice is likely to disappear completely from the Arctic by the year 2050. But what our study says is that it could happen much earlier, maybe by 2040. This is because the thickness of sea ice may actually be lesser than what is currently estimated using satellite data.

Over the past three decades, the volume of sea ice has decreased by about 70 per cent. What our study did is to reduce the error in this overestimation of sea ice thickness measurement from CryoSat-2. The study was published in the prestigious Geophysical Research Letters of the American Geophysical Union and was reported by various news and social media worldwide. Our next step is to collect more field measurements of sea ice thickness from different regions in the Arctic to confirm our theory.

Do you expect much variation in different regions of the Arctic?

The Arctic is an ocean surrounded by land, covering regions of Canada, the United States, Norway, Finland, Russia, Iceland, Sweden and Denmark (including Greenland). So there is a lot of characteristic variability in climate and differences in sea ice types found in these regions.

What is this due to?

The variability in weather patterns defines the characteristic climate of these regions. The general impression is that as we travel closer to the North Pole we feel colder and as we move away from the pole we feel relatively less cold. For example, the Russian and Siberian Arctic regions are extremely cold, as compared to, for example, the Canadian Arctic. The Norwegian Arctic has more open waters because of its close proximity to the warm Atlantic Ocean. Moreover, snow falling in the Norwegian Arctic is also high because of the greater moisture in the warmer atmosphere. Sea ice found in certain regions is less salty. For example, ice forming on the Baltic Sea is less salty because of the freshwater run-off from rivers into the ocean. So, there are a lot of location-specific differences in the way the sea ice forms and the amount of snow that falls on top of sea ice. Therefore, from our study’s perspective, the detected error in sea ice thickness which needs to be accounted from CryoSat-2 data also varies from place to place.

That is a large area you have to cover then.

To conduct fieldwork on sea ice covering the whole Arctic is logistically impossible. So, we choose specific sea ice areas in different regions which have characteristic sea ice features of that particular region. Moreover, we choose locations that are close to the permanent Arctic research stations established by different countries. For example, Canada has established the Canadian High Arctic Research Station in Cambridge Bay, Nunavut Province, located at 69° North. Another example is the Polar Continental Shelf Project research station, located in Resolute Bay, again in the Canadian Arctic (74° North). In the last six years, we have conducted field expeditions to these regions and other such locations across the Arctic. I was fortunate to participate in these expeditions of the University of Calgary’s Cryosphere Climate Research Group, 12 times till date, to many regions within the Arctic, including close to the North Pole, at 86° North—almost right on top of the planet. Another journey is scheduled this April. Unlike the South Pole which is on a continent, there is no fixed point that you can call the North Pole because it is an ocean and the magnetic North Pole and the geographic North Pole never coincide.

Do scientists have an estimation of the reduction of sea ice in the Arctic?

Yes. Different radar satellites have been continuously monitoring and measuring the Arctic sea ice concentration, thickness, extent, and so on since the late 1970s. Over the past 30 years, the Arctic sea ice volume has been found to have decreased substantially, by over 10 per cent per decade, which is alarming.

Has it been a declining trend throughout or was it a zig-zag variation?

It has almost been a declining trend throughout, over these 30 years. That is why climate modellers have predicted that Arctic sea ice may likely disappear by 2050. Sea ice will still be forming during the winter season, but it will all melt away very early because of increasing Arctic warming.

From your study, you are not saying when this will happen. If it is not 2050, then by when?

We are trying to correct the overestimated Arctic sea ice thickness measured by CryoSat-2. With the data we have at present and estimates based on that, from 2040 onwards we may see sea ice in the Arctic disappearing completely towards the end of every annual season, or the end of August every year.

Your study has been conducted on what you term as “first-year sea ice”. What does the term mean and what is its significance?

The annual growth cycle of Arctic sea ice starts from September, when the sun starts going down the horizon and polar darkness sets in. By October-November, the sun disappears completely for almost 24 hours, and the Arctic becomes completely dark and extremely cold. This triggers the freezing of the Arctic Ocean, leading to sea ice growth, which continues to thicken until the end of April. With snow falling on top of sea ice, the sea ice thickness can reach up to two metres. When the sun starts showing up again for almost 24 hours by the end of May, increased solar radiation causes the melting of snow, followed by the gradual melting of sea ice. This melting continues until the end of August, when almost all the sea ice melts completely. This ice, which grows in September and melts away by next September, is what we call as “first-year sea ice”. However, not all sea ice melts completely. The sea ice which remains after the melting season is called “multi-year sea ice”. This will again continue growing in the next winter season, and multi-year sea ice becomes thicker and thicker, sometimes up to eight metres.

Why is your study concerned only about the “first-year ice” then?

Over the past 30 years, the Arctic has accumulated a lot of multi-year sea ice. But because of the earth’s rotation, every free moving object in the northern hemisphere moves clockwise or deflected to the right. This is called the “Coriolis force”. This inherently means that even the Arctic sea ice is moving clockwise around the North Pole constantly. As the ocean currents also follow the Coriolis force, the multi-year sea ice which has been accumulated over the years is moving continuously around the North Pole, and the majority of this ice drains off into the Atlantic Ocean, via east of Greenland. It takes up between two and 10 years for this process to complete, depending on the location where sea ice is formed.

The Atlantic Ocean is a warmer ocean, and because of the warmer ocean temperature, the older, thicker multi-year sea ice which drains into the Atlantic Ocean melts away quickly. Right now, in the Arctic, 75 per cent of sea ice is first-year sea ice, while the remaining 25 per cent is multi-year sea ice. That is why we are concentrating more on first-year sea ice. In the coming years, scientists believe that there will not be any multi-year sea ice remaining in the Arctic, and first-year sea ice will be dominant. However, ironically, first-year sea ice is already facing the effects of climate change.

From the 1980s onwards, we have been hearing a lot about Antarctica in the context of climate change. Why has the Arctic suddenly become a point of interest for everybody?

Antarctica is an icy continent disconnected from all permanent human settlements. The only settlements currently present in the Antarctic are the research stations of different countries. However, the Arctic is not like that. It is a geopolitically controversial area. It lies close to many of northernmost countries in the upper latitudes, like Canada, the U.S., Russia, Iceland, Greenland and the Scandinavian countries. Along a majority of these countries, pollution caused by industries and factories, automobiles, biomass burning, forest fires and shipping routes through the Arctic Ocean, have all affected the Arctic ecosystem, climate and traditional ways of living on land (for example, as in the case of the indigenous Inuit people). For instance, soot (black carbon) that is produced as a result of biomass burning and forest fires travels through the lower atmosphere and gets deposited on top of snow and darkens the snow. This eventually results in the polluted, blackened snow absorbing more heat from the sun, drastically increasing the rate of melting. Such alarming instances have been observed frequently in the Arctic.

Are the effects so widespread?

Very much. There are some glaciers in Greenland which are turning black because of soot and other pollutants. Even on Arctic sea ice located close to coastal areas, we have found “cryoconites” (black dust) on the sea ice surface. With more exposure of these polluted areas to sunlight, sea ice melts faster.

Referring to the previous question, a large number of people living in the Arctic depend on Arctic resources for their livelihood. However, in recent years, the number of human settlements in the Arctic has also increased, owing to industrialisation and commercial encroachment. Traditional lifestyles have changed and transformed into modern lifestyles. For example, there is even a shopping mall in Nuuk, Greenland.


What would you say is the most striking change in the Arctic because of climate change?

Twenty years ago, at higher latitudes in the Canadian Arctic, say in the mid-winter season in April, the air temperature would be -40° Celsius. On May 26, 2016, when we went to Cambridge Bay in the Canadian Arctic, the air temperature was close to zero degrees Celsius. That day we walked around on sea ice, with our winter clothing as well as shirts off. What other proof do you need to understand that the Arctic is warming? Another instance, which occurred in May 2017, was when we were travelling across Greenland Sea (80° North latitude); the recorded air temperature there then was five degrees above normal. The ocean temperature was +3° Celsius and the air temperature was -1° Celsius. All these instances are very alarming.

What is considered the “normal” temperature there during winter?

In a perfect Arctic scenario, during mid April to mid May, it should be at least -15° to -20° Celsius. Nowadays, it is warmer, hovering close to zero degree Celsius, affecting the snow-covered sea ice. Not only that, as I said earlier about the carbon deposits, the ice is not pure any longer. It is no longer crystal white but a kind of shady white and you find a lot of impurities. Pollution is high.

You were born in Kerala, a tropical place. You have been to both the Antarctic and the Arctic. Where do you think are the effects of climate change most obvious?

In the Arctic, without doubt. The Arctic has been getting vulnerably affected the most, consequently affecting all of us living in the southern latitudes. For example, this year, winter was severely cold with heavy snowfall in some regions of Canada and the U.S. It was termed “bomb cyclone”. Extreme cold air masses from the Arctic were pounding most of the eastern regions of Canada and the U.S., resulting in air temperatures dropping to a record-breaking -40° Celsius.

If the Arctic is set to grow warmer, what is in store there?

Over the next 10 to 20 years, scientists expect to see more open ocean waters in the Arctic, with significant reduction in sea ice extent and concentration. Countries lying in the northern hemisphere, such as the U.S., Canada and the Scandinavian countries are likely to experience more fluctuations in weather patterns. Even during winters, a time usually for wearing jackets, it will become more like “T-shirt weather”. That is one way to put it. We may see more shipping routes opening up in the Arctic, for both tourism and trade. With increased shipping traffic, oil spill disasters are likely to increase, which would inherently affect the survival of the Arctic marine ecosystem. Because there are huge reserves of oil and natural gas in the Arctic, oil companies are likely to establish drilling rigs. Overall, the Arctic will become a geopolitically sensitive region, with countries vying to get more access to its resources and to establish sovereignty.

How interesting or tough is working in the Arctic across the seasons?

There is no sunlight from September to December in the Arctic. During this period, it is completely dark. That is when sea ice grows. But, during that time, we can see the colourful “Aurora Borealis”, or Northern Lights. During early winter, by mid November to mid December, it is very cold. It can go down to -50° to -60° Celsius. When the sun comes out, it gets warmer, -30° Celsius to -20° Celsius; sometimes up to +5° to +10° Celsius. By late June, the ice starts melting and breaking up, leaving wide cracks on the ice, which makes it dangerous for us researchers to travel across sea ice for taking measurements.

Are sledges and dogs still in use or have they become a thing of the past? How do you travel from place to place?

Sea ice is relatively flat and so we drive across the sea ice. We use skidoos, or snow scooters, which have sledges to drag instruments along. In winter, if we are staying in a research station, we drive at least 50 to 70 km on sea ice. But once sea ice starts melting, huge cracks keep forming. Then it becomes more adventurous and dangerous. We still travel on snow scooters, but we ensure we stay safe and do not get stuck or fall into a crack. We go around the cracks. Moreover, we monitor sea ice melting closely from satellite images and decide our driving routes based on that. Safety is our main priority.

It is the Arctic Ocean. Do you not use icebreakers or ships?

In some places. In 2017, we went to the Norwegian Arctic, so we took a ship, a Norwegian icebreaker named R/V Lance from the Norwegian coastal city of Tromso. The ship broke through the sea ice and travelled across the Greenland Sea, close to 80° North.


What preparations do you have to make for these research trips? How do you plan for a journey into the Arctic?

We always plan well in advance. There are many crucial things to consider. One is field logistics that includes transporting field instruments to the Arctic. Then we need proper winter clothing and protective gear. Sometimes we ship frozen food along with logistics. Where there are remote communities, we purchase food from local markets. Our field expedition plans are always weather-dependent. The weather can be extremely unpredictable in the Arctic. First, we decide where we want to obtain field measurements based on our expertise by monitoring satellite images of the area and also knowledge from locals who live in Arctic communities. But the weather can change suddenly. There will be days when we are unable to travel to our field site because the weather may be extremely windy or so cloudy that we may not be able to see anything in front of us. Then it is really hard. But we usually take an Inuit guide who knows the ice and the other conditions well. Employing an Inuit also helps them earn their livelihood. Of course, we continuously check satellite images to confirm whether the field sites we choose are safe to travel. We normally choose a field site far away from land because closer to land, the contamination will be high. Based on GPS coordinates and our experience from previous field trips, we decide to take the safest route for our measurements. If we find the ice is thin, or there are cracks, it is indeed risky and sometimes we have to take alternative routes to reach our field sites.

Do you stay over or come back every day?

We sometimes stay in research stations or in temporary camps. Or commute back and forth. In the Arctic, there is no such concept as morning, evening or night.

How strange an experience was it for you?

In winters, when it is totally dark 24x7, there is no concept of “night”. At night, we are subconsciously inclined to sleep, even though we have to work. So, it takes quite a few days to adjust. It will still be “night” when we wake up. During summers, when the sun is always overhead, it is the opposite. There is sunlight 24x7. Even then, there is no sense of time. The sun will always be there. So normally, when I get tired, I sleep; but once I wake up even after 12 hours, I still see the sun above me.

What are the most striking sights and sounds of the Arctic you have come across?

The most striking sight is the Northern Lights during winter season, under clear starry skies. It is amazing.

What do you see then?

Instead of a dark sky with bright stars, we see an orange or purple or yellowish sky or a combination of beautiful colours dancing around in the sky. That is something different and beautiful and we often see it every day during dark Arctic winters. In summer, when the sun is there, it feels strange because we cannot see anything else around us except an icy, cold and flat desert. Even stranger is the feeling that we are actually standing on sea ice, which is in fact the Arctic Ocean itself. We always get a sense of being in the middle of nowhere. There is no vegetation. It is just ice. Nothing else. Just snow and ice. But if I drill through the ice, I see the ocean below me.

What sounds do you usually hear in this desolate place?

When it is not windy, the silence is profound. You could hear a pin drop, so to say.

Tell us about the indigenous people of the Arctic, the Inuit. Have these communities changed a lot? Or do they still stick to their traditional ways?

The older Inuit generation still lives the traditional way. They live together as joint families. But their major source of income and livelihood is via hunting polar bears and Arctic seals. The younger generation Inuit are also trained to hunt. That is their routine lifestyle. The government offers them a subsidy for housing and support for education, and so on. In some regions in the Canadian Arctic, there are community colleges and schools.

How has climate change affected them?

A lot, especially when it comes to hunting and migrating. If they have to go from one community to another, they have to necessarily travel through sea ice using skidoos. But, when sea ice disappears, with more open ocean, the possibility of migration and hunting becomes restricted. Then there is climate change affecting the open ocean waters. The ocean is getting warmer and even when there is open ocean, the abundance of commonly found fishes like the Arctic Char has reduced.

Is much development happening in the traditional areas of these people?

Yes. Their lifestyle has become much more modernised. There are mobile towers and Internet facilities in some regions of the Canadian Arctic. There are airports, in places like Cambridge Bay and Resolute Bay, where they have flights to southern Canadian cities like Yellowknife. So connectivity between traditional, protected places in the Arctic, with more cities and towns in the southern latitudes is gradually increasing. Tourism has also increased substantially in the traditional areas.

Is there resistance to these changes or do they welcome it all?

The older generation does not like it. The younger generation seems to be welcoming this change.

Does it lead to conflicts? What is the social impact of climate change on the indigenous people of the Arctic?

Let me give an example. There are supermarkets in these areas. A pack of orange juice that costs $4 in the southern cities costs $9 in these Arctic communities. Prices are high. There is no production there. So they import everything. With their incomes going down because of climate change, people are not able to afford exorbitantly priced goods, even for their daily needs. People are becoming more and more jobless and many are living on the edge of poverty. Alcoholism is rising in many of these areas. In Greenland, for example, suicide rates are very high and increasing. Because of climate change, even during summer when it should be clear and sunny, skies are cloudier, with frequent occurrences of rain. Many such changes are depressing from the point of view of these people.

How are these dramatic changes in climate affecting the animal life in the Arctic region?

The main source of food for polar bears are the Arctic seals and fish. When the extent of open ocean increases, polar bears cannot hunt much. It is all interlinked. Arctic seals need the ice cover to protect themselves from the polar bears. Moreover, ice is an insulator, so it protects animals from extreme cold. Reduction in the ice cover means loss of insulation. As ice becomes thin, or as the extent of open ocean increases, more sunlight penetrates the ocean, killing the phytoplankton and algae, the main sources of food for Arctic fish. As climate change affects the food web, the affected species are moving down. Recently, a picture of a polar bear had gone viral: it looked very skinny because of lack of food. Polar bears are usually white in colour. Nowadays, their fur looks more brownish white. The difference is very striking.

What is happening to the Arctic glaciers?

As the atmosphere gets warmer, glaciers melt at a faster rate. Unlike the melting of sea ice, when glaciers melt, it affects the sea level. There will be more fresh water influx into the ocean. For example, if the Greenland ice sheet melts, a major cause of concern now, it can substantially lead to global sea level rise.

Does it rain in the Arctic or is it always snowfall?

Yes, nowadays we see rainfall, which affects sea ice growth. Rain inhibits the growth process of sea ice and makes it very complex. Where we saw snowfall on sea ice, we are seeing rainfall nowadays.

Are instances of extreme weather such as storms or cyclones increasing in the Arctic?

Arctic cyclones are frequent nowadays. In fact, over the past two or three years, there are warm storms. Very warm storms that blow the ice away or melt the ice quickly.

When the extent of open ocean increases, are there not some beneficial effects to it, such as an increase in fishing grounds, for example?

Yes. Fishing grounds are extending and Arctic shipping trade routes are increasing. But the disadvantages outweigh the advantages. As shipping routes increase, it boosts tourism. Last year, Crystal Serenity, an icebreaker tourist ship, successfully crossed the North-West passage in the Arctic. The downside is that as such trips increase, pollution such as oil spills and noise pollution also increase. As tourism grows, more people will encroach into pristine lands. Though there is more economic value, it spells disaster from an environmental perspective. It affects the Arctic ecosystem a lot. For example, noise pollution from ships affects animals, a lot of waste material gets dumped in the Arctic, and so on.

Is the increase in Arctic shipping becoming that evident?

Yes. In the summer season, it is quite evident. In the winter, too, there is traffic, because the thickness of sea ice has decreased and so it is comparatively easy for ships to break through sea ice. Now that there is less of multi-year ice, and more first-year ice, it is easy to break through. On the other hand, if there was more of multi-year ice, it would have been very difficult for ships because the ice is very thick and strong.

Of late we hear a lot about permafrost in the context of climate change in the Arctic.

Permafrost is not ice. It is either soil, rock or sediment that has been frozen over for more than two consecutive years. Permafrost has been found to be a big catchment of methane. With more Arctic warming, permafrost melts and releases methane, which leads to enhanced global warming. This effect has been found more prominent in the Siberian Arctic.

You have been to Antarctica as well. How was the experience working there? Which is a harsher world for researchers, the Arctic or the Antarctic?

The Antarctic is a hundred times colder and harsher place to survive. It is very hostile. If something happens to us while working in the Arctic, they can airlift us to safety in six hours, at best. If it happened in Antarctica far away from the research station, then it is difficult. In Antarctica we do not live in a tent or any such. We work from research stations. More countries have one or more research stations there. In the Antarctic, our body feels nothing but the cold. There is no variability in temperature. It is always cold. In the Arctic, we do experience a variety of temperatures. We get to see penguins in the Antarctic and polar bears in the Arctic. I have been to the Antarctic, but I know every nook and corner of the Arctic, so to say, by now. Antarctica is a continent. It is a desolate place. The Arctic is an ocean. So the risk factor is higher in the Arctic. The effects of climate change are also more pronounced in the Arctic.

Is there any chance of Arctic ice returning to earlier levels, with the effects of climate change being reversed? Is there any sign that this is possible?

In winter, there will always be sea ice in the Arctic because it is dark and cold. So that is not going to change. But will the ice withstand climate change? No. So in future, during summer season, ice may likely melt at a faster rate than before and there will be more open ocean. The sea ice will go on disappearing in the summer. There is no sign of recovery. Anthropogenic factors are increasing, efforts to reduce global warming notwithstanding.

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