CR
Cryospheric Sciences

Cryospheric Sciences

Do Beers Go Stale in the Arctic? – Jakob Sievers

Do Beers Go Stale in the Arctic? – Jakob Sievers

A story about CO2 -fluxes between sea-ice and the atmosphere

What’s it all about?

Whenever I have had to describe my PhD research project to people outside of my research community, I have always found it useful to use an analogy most people are familiar with, namely beers. Now that I have the full attention of the entire class, allow me to explain. Say you were to find yourself at an outside café, grabbing a beer in the beautiful weather with your friends. You get caught up in the conversation and soon your beer is lukewarm and stale and you struggle with the last few drops while gesturing somewhat frantically at the waitress to bring you a new beer. What has happened? Well, the partial pressure of CO2 (pCO2) in the beer is much larger, relative to that of the atmosphere. This leads to gradual diffusion (or flux) of CO2 from the surface of the beer into the atmosphere, and eventually the establishment of an equilibrium pCO2 in the beer, similar to that of the atmosphere. Of course, you have probably been waving at the waitress long before the equilibrium is reached. Now imagine that you had performed this experiment in the cold of winter. The waitress brings you a beer and from the moment it reaches your table a thin layer of ice starts forming on the top. What happens with the CO2 levels now?

Though a bar would probably have been a nice place for fieldwork, obviously my fieldwork took place in a much colder environment, namely the arctic sea-ice in northeast Greenland. The kingdom of the sort of curious four-legged fella shown in the photo above. And the answer to the above question might be “nothing” in the case of a beer. I.e., the ice works as a sort of lid on the beer, preventing any fluxes of CO2 from occurring, but what about in a sea-ice environment? Until very recently the beer analogy would have applied equally well here, as most scientists would have told you that no CO2 fluxes could take place in this sort of environment. Accordingly, all climate models currently treat sea-ice covered regions as regions of no exchange in terms of CO2. Lately, however, a number of papers have been published, suggesting that fluxes can occur at different stages of the annual sea-ice cycle. The paradigm shift occurred when it was discovered that CO2 may be transported through brine channels within the sea-ice. Brine channels form within sea-ice because of the salt in the sea-water, and they tend to be larger if the temperature is higher. So, at the bottom of the ice where the ambient temperature is a balmy 0°C, the channels are largest (Fig. 1).

Figure 1: An actual photo of brine channels within sea-ice [Junge et al., 2001, Annals of Glaciology]

Figure 1: An actual photo of brine channels within sea-ice [Junge et al., 2001, Annals of Glaciology]

Processes – scratching the surface

It is thought that the bulk of fluxes occur primarily in the spring during sea-ice melting. To understand why, we have to go back to when the sea-ice is formed during wintertime. As the ice forms, salts and CO2 are concentrated in the brine channels, and are expelled into the ocean through the larger brine channels in the bottom of the ice. The process is called gravity drainage and refers to the sinking of the highly saline and cold brine water which is denser relative to the underlying sea-water. Some of the expelled CO2 will continue to the deeper ocean column and as such lead to a CO2 loss of the original surface system. Hence, upon springtime melting, the upper water column has less CO2 than the atmosphere, which then causes an uptake of CO2 from the atmosphere. I.e.: a re-carbonization of the beer, so to speak. The mechanism has been coined the sea-ice driven carbon pump and has been estimated to drive an annual uptake of 50 million tons of carbon annually in the arctic alone, constituting a significant fraction of the total CO2 uptake of the arctic ocean which is estimated to be 66-199 million tons of carbon annually. Hence, understanding the impact of this carbon pump is important, particularly because the impact of climate change is felt more dramatically in the arctic compared to the rest of the world. Sea-ice cover is becoming increasingly ephemeral and glacial freshwater runoff, which inherently has a low partial pressure of CO2, is becoming increasingly ubiquitous in the fjord systems.

What are the challenges in this field of study?

To incorporate the carbon pump into existing climate models we need first to understand the physical and biogeochemical processes which drive sea-ice carbon fluxes in both coastal and open water conditions as well as during the entire life-cycle of sea-ice. Sounds simple, right? Of course not. Like most experimental investigators in cryospheric sciences we are struggling with considerable logistical challenges in a vast and unforgiving environment, where temperature conditions often have instrument-developers shaking their head in disbelief. “We didn’t test the instrument for that sort of thing”. How reassuring. Secondly, there are substantial risks involved, both for people and instruments, when conducting experiments during periods of thin sea-ice, which also happen to be the periods in which fluxes are most pronounced, and thus all the more important to understand. Fortunately we are equipped with fairly unique vehicles for transportation during these conditions (Fig. 2). Finally, the fluxes that are reported on sea-ice are often significantly smaller than what is typically reported in terrestrial environments, leaving investigators at times struggling to discern actual measurements from artificial noise.

Figure 2: Our polar air-boat for safe and fast transportation on thin sea-ice. During the experiment this bad boy was typically referred to as a gasoline-to-noise converter. In this particular picture the air-boat is pictured on thick sea-ice, hence the use of normal winter clothing instead of marine safety suits. Photo: Jakob Sievers.

Figure 2: Our polar air-boat for safe and fast transportation on thin sea-ice. During the experiment this bad boy was typically referred to as a gasoline-to-noise converter. In this particular picture the air-boat is pictured on thick sea-ice, hence the use of normal winter clothing instead of marine safety suits. Photo: Jakob Sievers.

What did I focus on during my PhD?

A common method for flux-observation is the micrometeorological Eddy Covariance method. It involves setting up a 2-5m high tower on a surface of interest and at the top installing:

(1) A three-dimensional ultrasonic anemometer, which measures 3D wind patterns,

(2) A gas analyzer, which measures the atmospheric concentration of e.g. H2O, CO2 or CH4 depending on which type of flux you are interested in.

Figure 3: Our eddy covariance tower on thin ice (20cm) in the outermost region of Young Sound (NE Greenland). Photo: Jakob Sievers.

Figure 3: Our eddy covariance tower on thin ice (20cm) in the outermost region of Young Sound (NE Greenland). Photo: Jakob Sievers.

Together they allow for calculation of the average flux in an upwind area in front of the tower. This area will vary in size depending on the height of the tower and wind-conditions. One of our instrument towers are shown in Fig. 3. From a mathematical standpoint the method is very simple, but it requires a number of quite complicated assumptions concerning the characteristic wind-patterns of the environment in question. Often these assumptions are not discussed in detail in papers. During my PhD I found that because most fluxes in a sea-ice environment are so small the critical assumptions began breaking down. It seemed that nearly all observations reflected large-scale meteorological patterns and flow-characteristics of the topography instead of fluxes in the local area of interest. Realizing this, I successfully developed and tested a very comprehensive data-analysis method to disentangle contributions of interest and contributions which were not reflective of the local environment of interest. Due to the technical nature of this new method I will not elaborate here, except to say that it was recently published in the Journal of Atmospheric Chemistry and Physics. Subsequently I was able to analyze simultaneous observations of CO2-fluxes and environmental parameters such as site energy balance and wind-speed to achieve a better understanding of some basic causal relationships for CO2 fluxes in a sea-ice environment.

Because this field of study is so new, and in-situ experiments are so challenging, much work is still needed but hopefully we will soon have a sufficiently detailed understanding of the physical and biogeochemical factors driving CO2 fluxes in the sea-ice environment, to be able to develop a model relationship and upscale that to all polar regions in which sea-ice exist.

Figure 4: An unexpected challenge during fieldwork: invasion by sled dog pups. Photo: Karl Attard.

Figure 4: An unexpected challenge during fieldwork: invasion by sled dog pups. Photo: Karl Attard.

I would like to leave you with one final picture illustrating a somewhat unexpected challenge during our experiment: having to reclaim our instruments and tools from the sled dog pups (Fig. 4).

Jakob Sievers ( Arctic Research Centre / Aarhus University) has just completed his PhD at Aarhus University in Denmark as part of the DEFROST project. He is interested in the physical and biogeochemical drivers of CO2 cycling in sea-ice environments and the development of flux models and flux observation methods under these challenging circumstances. He is currently seeking funding for the purpose of continuing his research in northern Norway.

Only extremes – Babis Charalampidis

Only extremes – Babis Charalampidis

– In fieldwork, you have no average. You just have extremes.

When Daniel spoke his mind out loud we were facing a bright sunny day coming in from the opening of our tent. We were very glad to see that and ready to engage with our glaciological tasks. Our camp site was at the immediate fore field of the A. P. Olsen ice cap in Northeast Greenland. We had arrived there the previous evening and had two days left to spend for our science up on the ice. But, on Saturday 30 August, we had to return to Tyrolerfjorden, no-matter-what. It had to happen in one-go, which means a 12-hour hike, 30 kilometers, carrying everything. Our appointment with Kenny was 00:30 hours at its narrow coast, so he can provide us a safe passage with the boat back to the ZERO station. The weather was closing in again on Sunday and with four days of supplies left, we just had to make things happen.

The author posing against a background of mountains (Credit: Daniel Binder)

Arctic fieldwork: Pose and reality. (Credit: Daniel Binder)

Daniel’s statement is very funny because it is actually very much true. Polar scientists always post their greatest photos, where they look like awesome polar explorers, implying that everything was completed like piece-of-cake. I do that too. But, there is always the other side of every story. Any fieldworker in the Arctic can verify that no matter how much experience you have or how hardened you have become through the years, every new mission is absolutely unique and different in many ways from all the previous ones. You have to prepare yourself the best way you can and when the time comes, perform your absolute best. Then, you have to also just hope for the best.

The initial plan was simple really. Two glaciers on the Northeast coast monitored by two institutes, ZAMG and GEUS, to be visited by a two-person mission, one from each institute, right? The team would be an alpine glaciologist with experience in the Austrian glaciers and an ice sheet glaciologist with experience in Greenland, both familiar with Zackenberg. End-of-summer mission implies that there is no sea ice in the fjords, so the team would have to hike everywhere. It also implies that there will be limited if any snow cover on the ice fields. Right…

When we began the first part of the mission on Freya glacier, the reality was quite different from our expectations. The biggest part of the glacier was still covered in snow. We were glad to see that, since it implied a positive mass budget year for Freya. On the other hand, since this was unexpected and we didn’t have our snow shoes with us, every step that we made was a struggle with the snow cover trying to swallow our legs while we are carrying all our equipment. Myself, I am what Daniel calls a “spoiled glaciologist”. Lightweight guy, I am definitely not as strong as he is, always riding on helicopters, twin otters and ski-doos. Seeing this genuine mountaineer also exhausted at the end of that first day on Freya made me feel a bit better about my performance. Of course, he was carrying about 10-20 kilos more on his back. Nevermind that.

figure_map

Map of the wider region of Zackenberg (Geodætisk Institut).

Sleeping on the side moraine of Freya inside bivouac sacks was also a new experience for me. We were glad not to experience fierce weather, so it was overall not too bad. But the fact is that in a bivouac, you end up quite quickly in a pool of liquefied water vapor that rains down on your face. Remedy is not too easy since as soon as you open the sack, you are exposed to the freezing glacial air. Fever in the morning was guaranteed for me.

Back at the ZERO station and before the hike to A. P. Olsen land, our preparations definitely included snow shoes. The previous days on Freya, we were able to spot the Argo glacier, the East-flowing glacier of the A. P. Olsen ice cap, on the horizon. It seemed to have an extended ablation zone with no snow cover, but since our plans included a visit in the upper GlacioBasis station, we thought that snow shoes would come in handy. As it turned out that was a really wise decision.

On Saturday 23 August we began the second part of our mission. Kenny and Lars dropped us off with the boat at the north coast of Tyrolerfjorden, west of Zackenberg and opposite of Eiger on the Clavering island. The weather was not inviting, cloudy atmosphere with small droplets falling now and then, but nothing too alarming. Our greatest concern at that time was crossing successfully the river at Store Sødal that may or may not be raging and full of water. As it turned out, crossing the river was not too challenging, since the flow at the end of the summer season is significantly reduced. But, the persistent cloud cover had gotten very thick by early evening and resulted in rain and eventually a storm.

Hard tasks and rewarding views (Credit: Babis Charalampidis).

Hard tasks and rewarding views (Credit: Babis Charalampidis).

While being in the proglacial valley of the Argo glacier, we were still closer to Store Sødal than to the ice cap when we decided to set camp and take shelter from the storm. We were definitely glad to get a bit dry, but we knew that this was a far from ideal situation. In this region, a lot of furry animals like to hang out. Snow foxes, arctic hare, but also bigger ones: muskoxen, polar bears… Any close encounter with them was far from our desires and although we were equipped with a flare gun and a rifle, one always prefers to return them unused, when one gets to return. We could only hope that our training and instinct would serve us well, should the circumstances require it.

Sleeping in the tent was frustrating. Every noise from outside – the wind, rock falls, the river – were keeping us from relaxing and enjoying our sleeps. In the morning, the storm was still going on. What we couldn’t have guessed at the time is that it would last for more than three days. Our initial awareness turned into prolonged sleeping sessions. In the interest of carrying less weight, we didn’t have with us any books or card games. Our daily routine included frequent chats during coffee times that intervened between our 2-3 hourly naps. A big moment every day, was 8 pm when we would call Kenny to let him know we’re doing fine and learn the weather forecast. Sadly, we had to hear the words: “Still stormy forecast, boys” quite a bit. The mood would catch up later in the evening when we would have our modest dinner and finish the day with cognac and cigarettes.

Good times, bad times (Credit: Babis Charamlapida).

Good times, bad times (Credit: Babis Charamlapida).

The time came when we heard good news: “Tomorrow, Wednesday 27th at noon sky clears up, boys”! And so it did. But, hiking after such a prolonged period in horizontal position was not something to derive pleasure from. By the end of that day, exhausted as we were, we managed to set camp at the very front of the glacier. Having wasted three days of supplies, we knew that we wouldn’t make it to the upper station. But, also one glimpse at the glacier predetermined that we will be slow again: The rain storm at the bottom of the valley was in fact a snow storm at the ice cap. The snow cover was everywhere at least half a meter and although we would be faster than on Freya with the snow shoes, we wouldn’t be as fast as we had hoped.

We successfully completed most of our tasks on A. P. Olsen and we definitely enjoyed this expedition. The scenery is always breathtaking and after all, this mission was more like an adventure of two friends than conventional glaciological fieldwork. But, it is also a fact that we overworked ourselves.

Last day on A. P Olsen and last hours of hike the next day before our pick-up from Tyrolerfjorden (Credit: Babis Charamlapida).

Last day on A. P Olsen and last hours of hike the next day before our pick-up from Tyrolerfjorden (Credit: Babis Charamlapida).

It is always good to remember that some moments throughout the process can be quite tough. In the end, this is probably the case with everything in life. The journey teaches you a few things. I will never forget the pain all over my body after the last hike from the ice cap to Tyrolerfjorden, racing against the clock on very challenging terrain with full backpacks. I will never forget the sense of trust that was developed between me and Daniel, how well we collaborated, coexisted and in a sense completed each other on this trip. Finally, I will never forget to have always a small book and a deck of cards with me.

Babis Charalampidis (GEUS/Uppsala University) is an Uppsala University PhD student within the SVALI project, based at the Geological Survey of Denmark and Greenland and supervised by Dirk van As. He is interested in the Greenland ice sheet’s mas budget, particularly the link between energy balance and subsurface processes such as percolation and refreezing. He studies the changes of the lower accumulation area of the southwest of the ice sheet in a warming climate, based on in situ observations.

Four years in Tibet – Eva Huintjes

Four years in Tibet – Eva Huintjes

The Tibetan Plateau – area: 2.5 million km2, mean elevation: 4,700 m a.s.l., surrounded by a series of high mountain ranges that are home to some of the world’s highest peaks: Himalayas, Karakoram, Pamir, Kunlun Shan. Considering these characteristics and the unique cultural heritage of Tibet the decision was easy when I was asked if I am interested working in a project on the regional patterns of glacier change on the Tibetan Plateau. And of course, we had to do a lot of field work to collect atmospheric and glaciological data :-). Between 2009 and 2012 we could realise seven field campaigns over three to four weeks to two different glaciers.

The Tibetan Plateau with location of the studied glaciers. The red stars mark the glaciers with in-situ measurements.

The Tibetan Plateau with location of the studied glaciers. The red stars mark the glaciers with in-situ measurements. Map by T. Bolch.

The journey always started at Lhasa airport. When leaving the plane I usually felt a little bit dizzy. Who wonders, air pressure is only 65% of that at sea level. In the following days in Lhasa every single time when walking up to the 3rd floor of our guesthouse at the Institute of Tibetan Plateau Research (ITP) I remembered that I was at 3,700 m a.s.l. By now I was glad that our schedule said that we stay in Lhasa for three nights before heading towards the snow and ice! Enough time to prepare our instruments, food and other equipment and to enjoy the tourist life… including headache and diarrhoea.

Glaciers on the Tibetan Plateau are usually terminating above 5,000 m a.s.l. and are only accessible by foot. Together with Chinese drivers and our colleagues from the ITP we left Lhasa by car, either for a one day ride to the north, to Nam Co Lake, and then another hiking day to Zhadang glacier (5,500 m a.s.l.). Or we went on a three day drive to the west, to the Kailash region, also followed by a one day ascent to Naimona’nyi glacier (5,600 m a.s.l.).

Local Tibetan people at Naimona’nyi glacier. Credit: Benjamin Schröter.

Local Tibetan people at Naimona’nyi glacier. Credit: Benjamin Schröter.

Generally, we spent two to three days in between to adapt to the altitude. With the support of local Tibetan people and yaks or horses we managed to bring all our stuff up to the glacier. I was always thankful only having to carry up myself and a small backpack :-).The torture of the ascent (at least for me) was totally forgotten when the tents were set up and we were rewarded with a great view down to the plateau (see picture at the top; camp at Naimona’nyi glacier. Credit: Benjamin Schröter).

However, we did not walk up to enjoy the landscape but to set up automatic weather stations (AWS) on or near the glacier and to conduct additional glaciological measurements. The AWS measure various atmospheric as well as surface and subsurface parameters. We also set up two time-lapse camera systems that took daily pictures of the glacier over three years. My colleagues at TU Dresden (Germany) geo-referenced and orthorectified these pictures to derive a daily snow line.

AWS at Naimona’nyi glacier in 2011. Credit: Christoph Schneider.

AWS at Naimona’nyi glacier in 2011. Credit: Christoph Schneider.

Usually nights up there were cold and restless and the days were quite exhausting. Air pressure drops to 50% of that at sea level. Thus, most of us were really happy when we successfully finished our measurements and repair work and walked down again after a few days to one week at the glacier side.

AWS at Zhadang glacier; left: 2009; right: after the ablation season in 2010. Credit: Christoph Schneider and Fabien Maussion.

AWS at Zhadang glacier; left: 2009; right: after the ablation season in 2010. Credit: Christoph Schneider and Fabien Maussion.

When returning home in the office the real work was only just beginning. We set up a physically-based ‘COupled Snowpack and Ice surface energy and MAss balance model’ (COSIMA) that accounts for subsurface processes like melt water percolation, retention and refreezing. The collected in-situ measurements are used to calibrate, run and evaluate the model. Forced with atmospheric model data (High Asia Refined analysis; HAR) we then applied the model to five glaciers on the Tibetan Plateau (see map above). From every regional study we obtained a 10-year time series of glacier-wide surface energy and mass balance components. This data set helps us to further understand the role of the different energy and mass balance components for glacier change in the different climate regions of the Tibetan Plateau. We also hope to increase the knowledge on the various driving mechanisms for energy and mass balance on Tibetan glaciers.

Schematic overview of COSIMA by E. Huintjes.

Schematic overview of COSIMA by E. Huintjes.

 

Illustration of the ‘COupled Snowpack and Ice surface energy and MAss balance model’ (COSIMA). Tair: air temperature; RH: relative humidity; ws: wind speed; N: cloud cover; ρair: air density; SWin: shortwave incoming radiation; SWout: shortwave outgoing radiation; α: albedo; LWin: longwave incoming radiation; LWout: longwave outgoing radiation; Qsens: turbulent sensible heat flux; Qlat: turbulent latent heat flux; Qmelt: energy flux for melting; QC: conductive heat flux; QPS: energy flux from penetrating SW radiation; Ts: surface temperature; Tb: bottom temperature; Ti: temperature of the snow/ice layer i; ρi: density of layer i; wi: liquid water content of layer i.

 

 

 

Follow this link to see the animated time series of the daily snow line evolution at Zhadang glacier, 2010-2012: http://www.klimageo.rwth-aachen.de/index.php?id=tibet_snowlines0&L=1

 

Eva Huintjes is PostDoc at RWTH Aachen University, Germany. In December 2014 she finished her PhD on ‘Energy and mass balance modelling for glaciers on the Tibetan Plateau – Extension, validation and application of a coupled snow and energy balance model’ supervised by Prof. Christoph Schneider. She is interested in understanding the different regional patterns of glacier surface energy and mass balance components and their driving mechanisms on the Tibetan Plateau and in other glaciated regions. Currently she is applying the model to glaciers in southeastern Tibet to reconstruct Little Ice Age climate conditions and to glaciers in the Tianshan (northwestern China).

The bi-polar behaviour of surge-type glaciers – Heidi Sevestre

The bi-polar behaviour of surge-type glaciers – Heidi Sevestre

Surge-type glaciers are the bi-polar member of the family of glacier dynamics. Every now and then they go into a complete fury and nobody really understands why.

What are surge-type glaciers?
Surge-type glaciers typically go through what we call the “surge cycle”. It is divided into two phases; a long quiescent phase during which the glacier is more or less dormant, followed by much shorter phase called “the surge”. Glacier velocities during the surge can typically reach 100 to 1000 the quiescence velocities. Velocities of up to 40 m per day were measured in Alaska during the surge of Variegated glacier.
The duration of the surge cycle varies from region to region. It tends to average around 20 years in Alaska, and 100 years or more in the Arctic.

What really triggers the surge of glaciers has always been an enigma in glaciology. Their unpredictable behaviour, and the dramatic and dangerous nature of the surge phase have always prevented extensive fieldwork to collect much needed in-situ data. Only a handful of studies have managed to obtain field data on glaciers before, during and after the surge of a glacier.

Distribution of surge-type glaciers in the world. Normal glaciers are blue, surge-type glaciers are represented by pink dots (credits: Sevestre and Benn, submitted)

Distribution of surge-type glaciers in the world. Normal glaciers are blue, surge-type glaciers are represented by pink dots (credits: Sevestre and Benn, submitted)

Where are they found?
Surge-type glaciers are distributed in a “non-random” fashion, meaning that they do not uniformly pepper all the glacierized regions on Earth, but contrarily gather in narrow clusters only found in some regions. We think that cracking the code of their distribution might lead us to a better understanding of the causes of surging.
A strong concentration of surge-type glaciers can be found in the sub- and high-Arctic, namely Alaska, Arctic Canada, Greenland, Iceland, Svalbard, Novaya Zemlya and Karakoram. Another popular area for these glaciers is western central Asia with the Karakoram, Tian Shan and Pamirs. Sporadic clusters of a few individuals have also been identified in the Andes, Caucasus and Kamchatka (See Fig. 1).

Our contribution to the question:
A large part of our work has consisted in building a global inventory of all observed/identified surge-type glaciers in the world. This has enabled us to perform the first global statistical analyses on these glaciers. Comparing the geometry and climatic distribution between normal and surge-type glaciers has yield very interesting results.

Fieldwork has also been an essential component of our work. As a group fully based in Svalbard, we have no excuses not to do get out in the field and collect top quality data. Svalbard is actually of huge interest for us as the population of identified surge-type glaciers represent 20% of all the glaciers on the archipelago.

By using a Ground Penetrating Radar (GPR) we have been able to look at glacier thickness and ice temperature on 15 different surge-type glaciers. These attributes are essential to map the thermal structure of the glaciers and understand further their potential surge mechanisms. As extensive as this may sounds, GPR-ing glaciers in Svalbard is actually quite an enjoyable task to do as the whole system can be towed by a snow scooter, and hundreds of kilometres of data can be collected in just a couple of days (see figure 2).

An “all seeing eye” is our best ally to observe spatial patterns of surging on the archipelago. Remote sensing data is really the only way we can catch surges in their very early stages. At the end of last year, we acquired pairs of TerraSar-X images covering most of the archipelago, and derived surface velocities from there. We discovered that no less than 17 glaciers are currently actively surging!

Driving in straight lines on a glacier in Svalbard = collecting GPR data (credits: Nick Hulton).

Driving in straight lines on a glacier in Svalbard = collecting GPR data (credits: Nick Hulton).

So… why do they surge?
First, we know how glaciers can surge. They can sustain such high velocities over months or years by having water at their base, lubricating their movement. But as soon as the water escapes, the surge terminates.
Over the past decades, two models of surging have been developed, each trying to understand how glaciers with different thermal structures can surge. Glaciers can either be “warm bedded” meaning that ice at their base is just at the point of melting; or “cold-bedded” if their ice is below the point of melting. Glaciers with a fully warm base have been observed to surge, as well as glaciers with a warm core surrounded by cold ice. The first model suppose that a switch in the configuration of the basal meltwater drainage system could lead to a surge, while the second suggests that surging could be caused by a change in the basal temperature from cold to warm. In both models, water eventually becomes trapped under the glacier, removing any friction at its base, and enabling it so move at high speeds.
There is still a lot to understand about these glaciers, and we hope that our results will cast a new light on the weird and wonderful world of surging glaciers!

Time lapse imagery

Follow this link to see a time lapse of the surge of Paulabreen, Svalbard:

http://www.polarresearch.net/index.php/polar/rt/suppFiles/11106/0


Heidi Sevestre is a PhD student based at the University Centre in Svalbard and supervised by Prof. Doug Benn and Prof. Jon Ove Hagen. Heidi is interested in glacier dynamics, particularly the mechanisms of glacier surges. She studies the global distribution of surging glaciers and their regional specificities, while field data is collected in Svalbard.

Heidi tweets as @HeidiSevestre.

­Around the Poles in approx. 100 minutes: Earth Observation for Climate Science and the Cryosphere – Anna Maria Trofaier and Anne Stefaniak

­Around the Poles in approx. 100 minutes: Earth Observation for Climate Science and the Cryosphere – Anna Maria Trofaier and Anne Stefaniak

Everyday we come into contact with technology that has changed the way we work, live and even think. Yet it is still easy to forget how integral satellite technology is to our daily lives; over two thousand artificial satellites currently orbit our planet – satellites for navigation, for telecommunication, for meteorology, and for environmental and climate monitoring. The latter two categories fall within the field of Earth Observation (EO). These satellites follow either Geostationary Orbits (GEOs) or Low Earth Orbits (LEOs). LEO satellites zoom around the globe, taking just over 1.5 hours to complete a cycle, collecting data crucial to our understanding of the Earth and its climate system. Parameters that represent the characteristics of the climate system are called Essential Climate Variables (ECVs) and in order to be able to monitor a changing climate we need to create long-term, global ECV records. Establishing these archives is our mission! In 2010 the Global Climate Observing System (GCOS), in support of the UN Framework Convention on Climate Change (UNFCCC), identified 50 ECVs. Out of these 50, 13 ECVs – those that currently are technically feasible to observe from space, that were not already covered by existing projects, and for which the European Space Agency (ESA) could provide a unique and significant contribution to the scientific community – have been selected and incorporated in 15 projects; this is the ESA Climate Change Initiative (CCI).

Focus on cryosphere

We all know the cryosphere is strongly linked to climate, contributing to the Earth’s thermal inertia. The cryosphere is a climate driver, and at the same time it is also an indicator of climate change; the cryosphere interacts with the climate system and reacts to changes in climate. Take for instance the populist example of a climate change indicator: Ice melt and associated global sea level rise. The magnitude of global and regional sea level change, and hence their consequences, need to be further explored by research such as glacier and ice sheet mass balance studies. In order to adapt to the effects of a changing cryosphere, we need to monitor the frozen parts of our world closely.

This is where the ESA CCI may provide some valuable data for your own research. Currently, there are four CCI projects specifically dedicated to the cryosphere (although there are others that are linked to cryospheric research such as ‘Sea Level’ and ‘Sea Surface Temperature’). These four cryosphere CCI projects are: ‘Glaciers’ , ‘Ice Sheets Greenland’, ‘Sea Ice’ and the new project ‘Ice Sheets Antarctica’, which will complement the original ‘Ice Sheets Greenland’ project.

View of East Greenland fjord

Photo credit: Nanna B. Karlsson

 

Developing useful data products, what’s new?

ESA has always tried to engage the scientific community (e.g. through its Data User Element (DUE) and Support To Science Element (STSE) ), encouraging input on identifying essential EO products and organising workshops that further communication amongst the – shall we call them – producers and users. However, this process is not always straightforward. In the past, it has often been the case that EO products do not appeal to potential user communities. Products are developed which are then not exploited because they do not represent the appropriate phenomenon, at the appropriate scale or with only limited consistency (the issue of frequent, consistent, comparable data being ever present). It is as if EO scientists, field scientists and modellers speak fundamentally different languages. The CCI projects have therefore been specifically designed with climate scientists in mind, centrally involving the climate community in each project. Requirements of the user communities were rigorously assessed and incorporated in the products’ development, and in addition a separate CCI project wholly dedicated to climate modelling, the ‘Climate Modelling User Group (CMUG)’, was set up.

 

Research at the ESA Climate Office

Apart from providing these data products we also do some of our own research. An example of a current study is an analysis of Arctic sea ice in relation to El Niño events. CCI datasets including Arctic sea ice concentration and thickness variables enable research to be carried out into the major influences of climate variability. We know that the Arctic sea ice trend is steadily decreasing annually but the effect of inter-annual climate variability is less well constrained. Using the CCI Sea Surface Temperature (SST) datasets, one of the most direct climate links of El Niño, correlations with sea ice can be investigated. El Niño events originate in the tropical Pacific with warmer temperatures affecting the global climate. These changes can be traced through the ECVs allowing us to determine the time it takes for it to affect global climate and in particular, Arctic sea ice. By establishing how inter-annual global climate variability influences sea ice, we can aid predictions of future events. EO satellites help provide some of the most globally comprehensive climate records, significantly aiding our understanding and adaptation to these climatic changes.

The CCI datasets provide climate records for a range of ECVs. However, cryospheric research is not simply limited to the above-mentioned CCI projects. Further research at the Climate Office focuses on using some of the land-based climate variables (including fire, land cover and soil moisture) as proxies for permafrost monitoring. Permafrost is an aspect of the cryosphere that cannot be directly monitored from space, but the development of proxies will support global scale monitoring, crucial to understanding changes in permafrost conditions.

EO has already, and continues to make significant changes to the way we investigate and gather new information about the planet we live on. However, there is still much that we do not yet know and hope to discover with the on-going monitoring of ECVs. As the products are updated to include more recent data, developing long-term records, our ability to decipher climate patterns and responses will be significantly aided.

 

Our changing planet

Nature is in a state of flux. We monitor our ever-changing world so we can understand the underlying processes. Our motivations may be economic or altruistic; they may be due to ambition or a thirst for knowledge. However, one thing is certain, the impacts of climate change will affect us all. Satellites help provide us with the bigger picture. Producing the ECV archives is one step towards effective monitoring in support of the international climate change community.

There are many words that describe Earth from space: unique, beautiful, vulnerable, alive – they all fit the bill. A recent ESA mission to the International Space Station was named Blue Dot; a rather fitting description of our place in the universe. In Jules Verne’s classic, the debate about how long it takes to journey around the world starts off with the quote: “The world has grown smaller, since a man can now go round it ten times more quickly than a hundred years ago.” Today LEO satellites orbit the world about 15 times per day with a repeat cycle of 12 days – that’s nearly seven times faster than Phileas Fogg’s record. The world has not grown smaller, but in fact the world that we see is vast and – to a degree – still unknown. Whatever your Weltanschauung, your perceptions of the world, your motivations and reasons for undertaking research, ultimately we monitor our planet for the benefit of society and the environment. Together, let us try to understand our planet and its climate system better!

 

To access any of the ESA CCI datasets please visit our website at http://www.esa-cci.org/ and click on the download link on the individual project sites. Registration is required but all data are free of charge and we welcome any comments with regard to use of the data.

 

Anna Maria Trofaier is a Postdoctoral Research Fellow and Anne Stefaniak is a Young Graduate Trainee working for the European Space Agency’s Climate Office at the European Centre for Space Applications and Telecommunications (ECSAT) on the Harwell-Oxford Campus in the UK.

You can follow them on Twitter @WhinnyHowe, @AnneStefaniak and @esaclimate.

 

This approximation is for Copernicus. LEO cycles can be anywhere between 1 – 2 hours depending on altitude.

4 Reasons Why You Should Get Involved as an Early Career Scientist (& a caveat) – Allen Pope

4 Reasons Why You Should Get Involved as an Early Career Scientist (& a caveat) – Allen Pope

You’re an early career scientist (ECS), or maybe you mentor one. So you know that we ECS are busy people, with responsibilities ranging from coursework to teaching, research to outreach, and labwork to fieldwork. And now there is this listicle (no, I’m not embarrassed about choosing this format) telling you to make time in your already packed day to volunteer some of your time to a(n early career) professional organization. Please, take a moment to hear me out.

When I was working on my master’s degree, I saw a workshop that I really wanted to attend, but I knew that similar previous events had been over-subscribed. So, I figured the best way to make sure I had a spot was to help organize the event myself. I enjoyed it and saw how much benefit both the attendees and myself got from the whole process. So, one thing led to another and eventually I became president of the Association of Polar Early Career Scientists, an organization created by ECS for ECS to be able to stimulate interdisciplinary and international research collaborations, and develop effective future leaders in polar research, education and outreach. Involvement with APECS transitioned to being one of the first elected early career members of the Council of the American Geophysical Union. Despite the time investment, these opportunities have been very valuable to me, so let me tell you why I (as an ECS) have gotten and continue to be involved in (early career) professional organizations.

Inukshuks

1) Networking & Building Connections

Networking doesn’t have to be a dirty word – really, it’s just meeting new people (choose your favorite way), finding shared interests, and keeping in touch with colleagues. Normally, people think of networking as just for extroverts – but there are ways to make it work for introverts, too.

Getting involved with a professional organization can be the key to making friends in your field and having conference buddies no matter where you go in the world. You can practice your networking skills with other ECS: share stories, grab a drink, find out about training courses or job opportunities, and build a support network. The shared mission of your volunteering will help bring you together.

And, if that weren’t enough, getting involved with a(n early career) professional organization can be the key – or the excuse – to meet that rock star scientist whose papers you’ve read. Except you’re not just a fan – you’re a colleague with a reason to interact. Take advantage of this for all it’s worth!

Taku A & the crew

2) Gaining Skills & Experience

There are so many things that volunteering for a(n early career) professional society can teach you. Leadership, running a meeting, building consensus, motivating a team, facilitating discussion, organizing an event, asking for funding, building a newsletter, communicating to diverse audiences – and the list goes on. Whether you bring it back to your research career (running a lab group takes a lot more skills than MATLAB), or discover that you have a knack and love for research coordination and decide to change career tracks, you come out on top by getting involved.

 

3) Practice Taking Initiative

Making things happen is satisfying and fun, pIMG_8985articularly when you’re in a field where results take years to come to fruition (if ever). No matter what career path you take, having the ability to be  “do-er” will be helpful. Being on some committees can help you achieve this – and being on others (in a good organization) will give you faith that recommendations put forwards by committees that only seem to provide advice are actually acted on and executed in meaningful ways.

Use your experience and expertise to go from talk to action – following through on meaningful contributions will get you noticed and allow you to continue to build and progress. But make sure that you’re choosing activities that are beneficial to you, too. As an ECS, you owe it to yourself to build skills and connections that you find fulfilling and that will contribute to your future career. Volunteering your time should always be a win-win situation for both you and the team you are working with.

4) Balance and Time Management

While your thesis or pushing out that next paper might seem like the only important thing right now, it won’t be forever. As you continue to grow in your career, multiple projects, proposals, reviews, etc. etc. will begin to pile up – and you’ll wish you had gained more experience handling the workload earlier on.

By getting involved in a professional organization as an ECS, you are getting an early start on training yourself to maintain a work-life balance. You will learn to prioritize what you need to get done and when. You will learn to balance your own time with other peoples’ schedules (both are valuable). You will also learn the importance of everybody knowing what time zone a conference call is on. Getting a thesis puppy might not be right for you, but having something that isn’t just your primary research can be healthy, gratifying, and productive all at the same time.

A Caveat: It’s all about the continuum.

“Getting involved” means different things for different groups – check out your options, put yourself out there, and find out what works for you. Whichever group you choose to get involved with (and I mention a few ideas below), a very important thing to keep in mind is that you want to interact with not only other ECS, but also experienced colleagues who will be able to mentor and guide you. Even ECS organizations should include not-so-early-career-scientists in as many ways as possible, bringing together a continuum and transferring knowledge, rather than reinventing the wheel.

There are many organizations you can get involved with as an ECS, whether it is an early-career specific group (like APECS, PYRN, or ICYS) or a larger international body (like EGU, AGU, IASC, etc.). You could “just” co-convene a session at a conference you are planning on attending (with other ECS or an experienced colleague), organize a discussion group or mentor panel in your department or at a regional meeting, or even set up a pub meet-up sometime. It’s all getting involved in your community: networking, building skills, taking initiative, and balancing your priorities.

OLYMPUS DIGITAL CAMERA

Allen Pope is a postdoc working at NSIDC and UW’s PSC, studying snow and ice, mostly from space. He tweets about the cryosphere, remote sensing, and few other things @PopePolar. Find out more about his research and what other projects he’s involved in at about.me/allenpope. The photos accompanying this blog entry are also by Allen.

My drone summer – Johnny Ryan

My drone summer – Johnny Ryan

In the summer of 2014, our group at Aberystwyth University and the University of Cambridge decided to pursue an ambitious but exciting field campaign in West Greenland. The aim was to survey Store Glacier once a day using a fixed-wing unmanned aerial vehicle (UAV) (see photo above for a view from the UAV on its way back from a mission with Store Glacier, West Greenland in the background). The UAV is equipped with a digital camera, which takes photos every two seconds during its dangerous 40 km sortie over the glacier. These photos can be stitched together using multi-view stereophotogrammetry to produce high-resolution orthoimages and digital elevation models of the glacier. We hope to use the data to provide insights into the process of calving and the interplay between the glacier and sea-ice mélange that forms during the winter and breaks up in late spring.

A) Landsat 8 true colour image of Store Glacier in August 2014 with the location of camp site. B) MODIS mosaic image of Greenland (Kargel et al., 2012, The Cryosphere) with location of Store Glacier which is situated in Uummannaq Bay.

A) Landsat 8 true colour image of Store Glacier in August 2014 with the location of camp site. B) MODIS mosaic image of Greenland (Kargel et al., 2012, The Cryosphere) with location of Store Glacier which is situated in Uummannaq Bay.

The field campaign started on 7th May 2014 when my colleague, Nick Toberg, and I were dropped off by a helicopter on a peninsula by side of Store Glacier. This site was to be our home for the next 10 weeks and as we watched the helicopter disappear down the fjord, there were not two lonelier men on Earth. Temperatures dropped quickly to -20 degrees as the sun set behind the mountains so it was important to set up camp and prepare for a chilly first night. We were well provided for, with a large mess/science dome tent, individual sleeping tents, generators, a stove, kerosene heaters and a table and camping chairs. By the 9th May we were ready to start flying missions over Store Glacier.

 

The camp with sleeping tents and mess/science tent. Generators and solar panels were used to charge laptops and UAV LiPo batteries.

The camp with sleeping tents and mess/science tent. Generators and solar panels were used to charge laptops and UAV LiPo batteries.

A typical day would consist of a lazy breakfast, followed by some reading or hiking during the morning. We would then have lunch and aim to fly the UAV at 3pm. Setting up the UAV took a few minutes and a typical survey would take 30 minutes. At the start of the field campaign, these 30 minutes would seem like a lifetime and we would usually be too worried and agitated to think of anything but the plane. I would pace up and down trying to remember whether I had checked a certain part or become increasingly nervous about the wind speed, which always seemed to increase as the plane started its mission. As time passed and more data was collected, we became more and more relaxed. We got to a point where, once the UAV was launched, we would go straight back into the mess tent and read our books. Then once, we heard the plane over our heads, we would head out and land it.

Inside the mess tent. Downloading the GPS, attitude and the locations of the camera triggers from the flight controller.

Inside the mess tent. Downloading the GPS, attitude and the locations of the camera triggers from the flight controller.

Once the plane was safely landed (see video below), which was difficult on the short, boulder-strewn runway, the photos would be downloaded from the SD card and the log files from the flight controller (see photo above). We would then check for damage and repair anything that needed fixing. Cooking and washing up duties were rotated every evening and we would watch a film (usually something starring Nick Cage) after dinner. After the film, we would head to our individual sleeping tents. There was something magical about brushing your teeth overlooking Store Glacier below, the Greenland Ice Sheet to the east and the beautiful fjord and rugged mountains to the west.

In total we completed 55 surveys of Store Glacier from early May to late July. Nick and I are still friends and are now processing the data. We hope to be able to provide some exciting results soon.

 

Johnny Ryan is a PhD student working at Aberystwyth University in Wales and is supervised by Prof. Alun Hubbard. He is interested in understanding the dynamics of the Greenland Ice Sheet and its fast flowing tidewater outlet glaciers. The primary tool Johnny uses for his research is a fixed-wing unmanned aerial vehicle (UAV) which can be used to survey the cryosphere at fine temporal and spatial scales. Currently he is using data collected by UAVs combined with timelapse camera imagery, meterological stations and tide gauges to investigate processes that control calving and the break-up of the ice melangé at Store Glacier. Johnny tweets as @glaciology_uavs .

 

Welcome!

Welcome!

Hello and welcome to the blog of the EGU Cryosphere Division.

This blog aims to spread the enthusiasm for ice in all its forms – from snow, glaciers and ice sheets, to ice crystals, extra-terrestrial ice bodies and isotopic ice composition.

The blog will feature stories related to cryospheric research, particularly the latest in fieldwork programmes, research projects and scientific results. With the help of beautiful imagery and riveting tales of hardships (or at least tales of cold conditions), we hope to inspire interest in the role of ice in our climate system.

The editor of the blog is Nanna B. Karlsson, the Young Scientist representative of the EGU Cryosphere Division. Researchers from the cryospheric community will contribute with content, making sure that the blog entries highlight the exciting and thrilling research projects that are engaging us at present.

The first blog entry will be from Johnny Ryan (Aberystwyth University, UK), who will write about his work with UAVs (Unmanned Aerial Vehicles) in Greenland. This is promising be an exciting insight into a new technique in glaciological fieldwork.

Next year there will be entries in a variety of subjects within the cryospheric field. We hope to take you to the world’s northernmost research institution in Svalbard, where Heidi Sevestre is conducting her research. We will go on an expedition with a wooden schooner to the fjords of Southern Greenland with Anne-Katrine Faber and Malte N. Winther (University of Copenhagen, Denmark). Eva Huintjes (RWTH Aachen University) will take us even further afield to the Tibetan Plateau where she conducted her PhD research. And Alexandra Messerli (University of Copenhagen, Denmark) will show us what is happening at the bed of a glacier when the melt season starts. All very exciting stuff – and lots more to come!

If you would like to write a blog entry about your research, please get in touch with the editor, especially if you are a young scientist! We welcome all contributions that fit broadly within the topic of cryospheric research.

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