Why to study the Arctic climate? Why do I want to go to the North Pole? What is this "SAS" expedition about?

 

Traveling up to the North Pole - isn't that everyone's dream? At least it has always been my dream - and finally a dream come true! My interest towards the Arctic (yes that is in the north) grew during my University studies: I wrote my Bachelor thesis at Helsinki University about the influence of clouds in the Arctic on the Arctic climate. Clouds in general has always been my passion - I think clouds are the window of the atmosphere: they can tell you about the current weather and tell you in case of a change in the weather is to be expected. Let me give you a small science peak into why clouds are som important:

Clouds in the Arctic

Clouds - consisting of condensed water droplets flying in the atmosphere - in general have two important affects in the weather and climate: 

1. give rise to precipitation: rain, snow, hail... This of course, affects our life: we might skip our picnic plans if it is raining, go out and build snowmen after a snow event or a farmer is frustrated after a hail event destroyed part of his harvest... Heavy precipitation can also give rise to flooding, but the absence of water leads to droughts. In the high Arctic, the precipitation is mainly snow, which has a high albedo and thus reflects more of the incoming solar radiation back to space. Rain on snow, on the other hand, decreases the albedo of the surface, and thus more solar energy can be absorbed by the surface and lead to surface warming and melt of snow and ice. So, now when we got into the radiation impact of clouds, lets add the second impact - point:
2. influence the energy exchange between the atmosphere and the surface - the radiative effects on the surface energy budget caused by the clouds is known as the cloud radiative forcing. Is basically tells you how much does the clouds influence the radiation compared to clear sky conditions. As you might know, radiation comes in a broadband and clouds affects both the incoming solar radiation (short wave radiation, SW) and outgoing thermal longwave radiation (LW). How clouds influence radiation also depends on the type of cloud (ice cloud, liquid cloud, mixed-phase clouds (both ice + liquid)), the thickness of the cloud and the number (and size) of droplets in the clouds. I won't go deeper there now, but let's speak a bit more about the cloud radiative forcing, focusing on the role of clouds in the Arctic, by the help of Fig.1.
1. Shortwave forcing (SW forcing): In the presence of clouds (left figure), part of the incoming solar-light will be reflected back to the space (see small orange arrow directed upward from the cloud). This has a cooling effect on the surface, since less solar radiation will reach the surface. Globally, clouds have a cooling effect on the surface, meaning that this SW forcing dominates the LW forcing (which is warming, see next point). However, NOTE the word "global" --> in the Arctic, there is a radiation deficit and the polar regions receive on average 40 % less compared to the equator (due to the fact that the incoming solar radiation need to travel a longer way to reach the poles, thereby being scattered and absorbed multiple times before reaching the surface. Secondly, the energy that reaches need to be shared over a larger area, leading to a radiation deficit at the poles. Thus, the SW radiation in the Arctic (cooling effect) is very small and also absent in the winter (with no solar light - "kaamos"), so the SW forcing is small or neglected. The dominant cloud impact on the radiation is thus the influence on the longwave radiation!
2. Longwave forcing (LW forcing): In the presence of clouds, the thermal radiation emitted by the surface will be back-reflected by the clouds, and thus contributing to a surface warming and melt of sea-ice and snow (blue arrows to the left). Thus, clouds on ice has a warming effect and the net cloud radiative forcing is actually positive in the Arctic! 

        If we look at the figure to the right (absence of clouds), the surface impact will be the opposite: Firstly, even though more solar-light can reach the surface, most of it will be reflected away due to the high reflectivity of the white surfaces in the Arctic. However, for exposed open ocean surfaces, meltponds or leads within the sea ice, more SW will be absorbed and could enhance the melting and warming. But, as said before, the incoming solar radiation is so small that its radiative impact on the surface is almost negligible. So, for the LW outgoing radiation (blue arrow upward), clouds won't be there to trap the outgoing radiation and thus will be lost in space. Of course, other greenhouse gases, such as CO2 and water vapour, can also trap the LW radiation, but the concentrations in the Arctic atmosphere is normally low and clouds has a high impact on the radiation. Thus, even though for a person standing on the ice a summer day, it feels nice and warm in the face, BUT actually the surface is freezing due to the loss of radiation, mainly due no clouds for trapping the heat. We can relate this warming effect to our normal life: If we are out on a winter-day, it feels colder in the absence of clouds, whereas in the presence of clouds, the temperature is warmer at the surface. 

Fig. 1 Cloud radiative forcing in the Arctic. Orange arrows indicate SW radiation, blue LW radiation. Left: influence with the presence of clouds (SW and LW forcing), Right: Impact on the radiation during clear sky conditions. Note the ice-albedo feedback depicted on the right plot (sea ice with higher albedo reflects most of the solar radiation back in space, whereas exposed ocean surfaces with lower albedo absorb more of the solar-light and thus enhance surface melting and warming.

Arctic Amplification

Why am I talking so much about clouds? Due to the different contributions of clouds through precipitation and radiative effects on the surface melt and warming, especially in the Arctic, clouds are an important contribution to the rapid Arctic warming seen in the Arctic - this phenomena (rapid warming seen in the Arctic compared to global trends in surface temperatures) is known as Arctic Amplification, causing dramatic changes in both Arctic sea ice loss and snow cover. It is complex system of processes that act - both locally such as local cloud formation and albedo effect and remotely as northward transport of warm and moist air or water by the atmosphere or the oceans - and on different scales (from large scale circulation to smaller scale cloud and aerosol / particle processes) on the Arctic climate. For example, large scale circulation can transport warm and moist air to the polar regions, giving rise to cloud formation, affecting the radiation balance and surface warming and melt. The conditions in the Arctic are highly variable and we can have a change in the temperature of 15 degrees on only one day, the formation of fog, change of wind speed and direction and the presence of clouds. 

In order to be able to model the Arctic climate correctly and forecast the Arctic climate change, it is therefore super important that all the processes involved are well represented in the climate models. Many of the processes are also parameterizied in the models, e.g. clouds that usually cover smaller areas than what the model can resolve, they are represented by a cloud scheme. As factors within the clouds with even smaller scales has an impact, it all gets complexed and adds uncertainties in climate models. Another factor that leads to uncertainties in climate models for polar regions is the lack of observations - observations are used to feed models and thus less processes need to be resolved for regions with no observations. The fewer observations, the higher the uncertainty of models to represent the the change in Arctic climate correctly.

My journey to become an Arctic researcher

So, after having that all said, I want to go back to the growth of my interest to the Arctic climate. After my bachelor I went to study abroad to Hamburg and took a course abbot cloud and aerosol physics, which increased my interest to clouds even more. I got also introduced to Svalbard from a good friend I met in Hamburg: There is a University on Svalbard in Longyearbyen where you can study polar meteorology in the Arctic (78 degrees north)! So I took the opportunity and applied for the winter period 2016 and I got accepted! This was one of the best times ever, being up in the Arctic and studying the polar climate while experiencing the Arctic climate is a perfect combo! We also went for fieldworks, both on shore for meteorological measurements and on the ocean for the polar oceanography course, which introduced me to fieldwork in the Arctic - and I loved it!! Below are some figures from my stay in Svalbard autumn 2016.

Fig. 2 On the way to the highest mountain in Longyearbyen - Nordenskiöldtoppen (1051m). Longyerbyen valley is down to the right and the Adventfjorden to the north, united with Isfjorden, originated from Greenland Sea.

Fig. 3 During our fieldwork on shore we got company from this little fellow. 

Fig. 4 On the top of Nordenskiöldtoppen. When leaving the town, we always have to carry rifles for our safety!

After being on Svalbard I really wished to be back again and felt this is my field - studying the Arctic climate! There are still so many unanswered questions and lot left for improving the understanding of processes involved in the rapid climate change in the Arctic, that I wanted to explore!

I finished my Master in Meteorology in December 2017 and was open for new challenges! I applied for a PhD position in Stockholm at the Meteorological Department at Stockholm University for a 4-year position, working on understanding processes behind warming and sea ice melt in the Arctic, using both observations and models and enlarge the understanding of the processes and thus improve climate prediction models. I got accepted and begun my journey as a PhD student in spring 2018. 

ACAS - Arctic climate across scales

I am enrolled in a project called ACAS - Arctic climate across scales - and it means exactly what it says: to look at all meteorological processes - on all scales - behind the rapid Arctic climate change and improve the understanding of these processes, doing this by the use of observations and numerical models. So far I have been working with 50 extreme warm events in the wintertime high Arctic and focusing on the dynamical processes behind these events, concentrating on the role of high-pressure systems and low-pressure systems and their interaction in providing favourable conditions for the warming in the Arctic to occur. My paper is soon to be published! Furthermore, I am currently enrolled in a project where we identify events over Arctic sea ice, obtaining a high positive anomaly (deviation from the "normal state") in the surface energy balance (since the energy balance is the one that finally determines the ice melt and surface warming - an excess of energy leads to surface warming). Also, I am looking at two warm events occurring in April 2020 during the MOSAiC expedition, a one year polar expedition where the German Icebreaker Polarstern was frozen into ice and drifted with the ice (MOSAiC). These two events are characterised by warm and moist air transport into the Arctic, guided by the present circulation patterns. This work in ongoing, but the warm-period interest a lot of scientists across different fields - from meteorologists to biologists and chemists. 

The aim of ACAS is to improve the understanding of these processes and collect more observations in order to fill in the knowledge gaps and thus improve climate models by reducing their uncertainties and the reasons behind the uncertainties. 

SAS - Synoptic Arctic Survey - 2021 - Polar expedition - 

I was so happy to be asked to be part of the Polar Expedition SAS - Synoptic Arctic Survey. This expedition was in the beginning planned for summer 2020, but we all know what happened that year.. Due to the ongoing Pandemic of COVID-19, the expedition was cancelled for 2020 but there were plans of postponing it to the following summer in 2021 instead. I was a bit afraid of not being able to participate since that year would be my last year of my PhD studies and thus rather stressful. 

But fortunately I got asked again and was able to join! Me and my colleague John Prytherch will be physically taking part of this expedition, whereas Michel Tjernström is our shore-based head in the work-package Arctic Climate Across Scales (ACAS). 

Synoptic Arctic Survey - SAS - is a polar expedition to the Arctic with the Swedish Icebreaker Oden (SAS blog), taking place this summer from August to September 2021. On board we will have a team of around 35 international scientist and a crew-personal consisting of around 40 people to make this expedition possible. The aim of this expedition is, by working together, to study the status and changes in the Arctic ekosystem, but also the meteorology behind it. We want to identify the fundamental issues, structures and hypothesis behind it and with this expedition, improve the understanding of them: interconnections between processes in the Arctic Ocean, how does the system respond to environmental forcing or the rapid climate change and identify the teleconnections of how a process in one region could affect another region by their interconnections. In order to assess these questions, many scientists from different fields need to physically come together, combine their brain resources by using similar methodologies. This Polar expedition SAS 2021 offers all of this: It is an opportunity for scientists to come together, collect samples of the ecosystem, focus on biological and chemical parameters, fluxes of gases, carbon cycle, conduct meteorological observations... and analyse the data while being in the correct environment and surrounded by other scientists burning for the same goal: Gain a better understanding of ALL the processes involved in the Arctic ecosystem and climate and get a better view of what is the present state of the system or ongoing changes seen in the Arctic. 

In Fig. 5 you can see the planned trip for our expedition: we start at LEG1 (white contour Northeast of Svalbard - yes we'll drive pass Svalbard but not stop there, but atleast I can wave to all my friends there!) and continue northwards to the Noth Pole (at the stop C). We do several small stops during the expedition, and nine 24-h Ice Stations, where we are allowed to go out on ice and working on ice. The trip continues anti-clockwise and then reaching the sea-border to northern Greenland (LEG5), and then returning in a zig-zag motion to the Yermak Plateau, north of Svalbard. We will travel over the Atlantic on Oden for around a week to come to start point and also one week after the expedition to get back to Helsingborg on 20th of September. 

Fig 5. Map over the Expedition route with 8 legs (white contour) and the  nine Ice stations (green circles, A-I) for 24-h stops during the expedition. Figure adapted from SASblog

Work on Oden with ACAS

During the expedition, me and John will be doing plenty of meteorological observations on the ship, as well as on the ice (then mostly gas flux measurements between the surface (melt ponds, leads or sea ice) and the atmosphere. The first days will be busy for us, running around on the 7th deck and installing all measurements we have in our weather station and making sure they are all running. Once we get that all set, we do continuous observations,  where maintenance of the instruments is required (or lowering the weather mast for de-icing after a fog event...). The instruments on the weather station are following:

• 2D anemometer (measures horisontal wind)
• Instruments measuring downward short- and long-wave radiation
• Sensors measuring temperature and humidity
• Downward pointing (out of the ship) infrared sensors measuring the surface temperature
• weather sensor for measuring visibility and precipitation
• Upward-pointing Ceilometer (active lidar measuring cloud base and cloud fractions)

Furthermore, we have a full set of remote sensing tools to look at vertical profiles of clouds:

• Microwave radiometer profiler (passive radiometer, catches the radio waves emitted from the atmosphere)
• Cloud radar (active radar system in monitoring clouds)

We also have a flux kit (with e.g. a super accurate and reliable 3D sonic anemometer for vertical winds and temperature) on the foremast of Oden,  measuring surface eddy-covariance fluxes of momentum, heat, water vapour, methane and carbon-dioxide. 

Finally, the main active task for us during the expedition is to launch four times a day (every 6 h) weather balloons (radio soundings) from the helipad in order to retain the vertical profile of the atmosphere regarding temperature, moisture, pressure and wind. From these measurements many other parameters can be calculated, giving valuable information about the current state of the atmosphere in the Arctic. A novelty of our work is that the output files from the soundings will be immediately transmitted for improving the forecasts, for both SMHI, but also utilised by other numerical weather prediction institutes, such as the European Center for Medium-Range Weather Forecasts (ECMWF).  Below in fig. 6 you can see a Photo over Oden (taken from the front, so the foremast is just cut off).

Fig. 6 Oden during the Arctic expedition in 2018. The weather station is located on the top (7th deck) and the remote sensing tools below it on the 4th deck. Photo: Michael Tjernström.

Finally, I will also take care of fog sampling during fog events occurring during the expedition. And I hope to be able to help out wherever needed and do some forecasts, help out our other 2 meteorologists joining the trip and get to fly with the helicopter in order to make measurements further away from the ship during some of our Ice Stations. 

Preparations to the expedition + Dancing Lindy Hop on the North Pole

There has been lot of preparations for this expedition, and excitement! I had to buy myself:

•  steel-toe shoes for working on the deck of the Icebreaker
• winter boots for work on the Sea ice
• warm and thick gloves for working on the ice
• thin glows for precision work on the deck
• more glows for other work assignments
• Sunglasses with a good protection against radiation (we do have daylight for 100 % of the days in summer)
•  Sun-protection for the skin
• VEGAN chocolate + download lindyhop music offline!
• ...

Working on ice requires proper equipment and the crew on Oden has prepared all for us - we will get a warm and isolating working suit to use while working several hours a day on the ice, but the boots are necessary for survival. Also, for launching weather balloons or working on the deck, there is always risk for stuff to fall down, and thus we are highly recommend to wear steal toe shoes. For the various work on the cruise, I need different glowes: thick ones for ice work, thin ones to tighten the string between the balloon and the small instrumentation box (sounding, that is measuring the parameters), and "normal" ones for other work! Also, we will be in the Arctic during summer, and thus have 24-h of daylight (Midnightsun). Even though the surface will be losing lot of energy (if there are no clouds right ;) ), we scientists working on the ice will be exposed to the sun and need to protect us - both with sunglasses and sun-protector. 

The temperature in the Arctic can be between -15 to 5 degrees, but of course with the wind it will feel much colder. Usually we have fog for 25 % of the time and super clear skies for 25 %, but low-level clouds can be present for more than 50 % of the time (some results from the Arctic expedition 2018, read more HERE). The wind is usually mild but can occasionally be really strong! Let's see how the launching of radiosoundings on a slippery (?) deck works out with winds blowing more than 10 m/s...

From the list above, especially the last point is very important for me! My biggest passion, apart from the Arctic, is Lindy Hop - as a dancer and as a dance teacher (Dance company). I love to dance, to spread the joy of my passion to others, to teach others to experience the same joy as I get out of dancing! To dance with all the lovely leaders and lead all the lovely followers, especially with my dance partners, but in general just to dance -  and with everyone! Dancing is a big part of my life! I guess "social dancing" can retain its meaning now during the cruise, if we can actually dance and change partners as we used to do before COVID... So, I have prepared by downloading swing music on my hard disk in order to continue dancing also on Oden - and maybe do a NorthPole Lindy Hop dance on the ice? Or dancing to a famous solo jazz routine "Shimsham" and perform it to live music on the north pole? Also, I am so excited to be able to teach dancing on the boat, I am sure all social activates are highly appreciated on board, as a balance to to hard work we do. Also, apart from dancing as free-time activities, there will be a gym, a cinema and 2 saunas on Oden!

Final words on the last day of Quarantine 

Today is my last day in Quarantine as mandatory safety preparations for the expedition - 8 days trapped in a hotel room. I am glad from all the support we have gotten from the organisers and other SAS participants, as well as all the valuable talks and videocalls with beloved friends and family, that I will miss during my trip! We won't have internet access on the ship, so this quarantine week has been a good opportunity to talk to as many as possible! The quarantine has been challenging, but now we are almost there! Tomorrow we will be transported to Oden and staying on shore for two days before departure on Monday 26th of July. 

I am soo excited for this trip - to return to the Arctic, experiencing its beauty in real life, performing meteorological measurements and launching weather balloons, enlarge my understanding of how these measurements are performed- This gives a different perspective to have been out in the field and is a great advantage! Maybe also an investment in a potential future career? 

Can't wait for the adventure to begin!

-> I aim for posting updates from the experiences during this trip while being up in the North. Follow me here in this blog if you want to take part of all the experiences that this summer with SAS Polar expedition will bring me!