First week of the Second icecamp - Icework and its challenges

 On Sunday (28 May) eve, Oden was parked at an icefloe for the second and final icecamp. As written in the last posting, this icecamp and the measurements done while staying here will be important, as it is NOW the melting is supposed to begin. The onset of sea ice melt and the processes responsible for triggering melt onset are the targets of our expedition, which makes these coming weeks super interesting for all scientists onboard Oden. Until now, we have stayed at the same icefloe for 1.5 weeks and the plan is to stay at least until Sunday (11 June) this week to retrieve a 2-week long timeserie of data at the same icefloe. EXCITING!

 

This icecamp has been full of surprises: rapidly changing weather and visibility that limit the work on the ice, characteristics of the icefloe and its drifting speed (we were moving with the floe approximately 16 km per 24h; around 25 cm/s!!) which also affects the possibility of Oden to be moored onto the icefloe and of course - our white visitors: the polarbears, create own challenges for ice work. I have already lost the counting of how many polarbears we have seen during this expedition - but must be up to at least 15 now (from which the last 6 have been only during two days while working on the ice! Read more about the experiences with polarbears and look at cute photos in the next posting). It feels like we see 3 new polarbears each day - sometimes they sneak close to Oden during the night! A few times scientists working on the ice (once including me) had to be evacuated by snowmobiles back to Oden because of polarbears heading towards the ship. We have been stationary for so long that our smell travels far and lures polarbears from hundreds of kilometers apart!

 

All these three factors (ice characteristics and its drifting, polarbears and weather) are challenges for working on the ice. It is a hard job to make a plan of the day, not only considering these three factors, but also taking all the limitations of different operations into account and make sure that for each site on the ice there is at least one polarbear guard. For example, if the helicopter is flying, no drone operations are allowed. In case of fog no ice work is allowed until the visibility gets better. On the other hand, the aerosol scientists interested in fog droplets are super happy during fog events, whereas ice work gets postponed and instruments onboard might need de-icing during fog. Coordination with everyone onboard is needed and wishes from the scientists are taken into account when the plan of the day is established by expedition leaders each day. The plan of the day can of course change throughout the day depending on sudden changes or unwanted (but cute!) visitors.

 

In this posting, I will guide you through the first week of the second icecamp with some stories and photos. Additionally, I will present the work of other scientists involved in other work-packages, such as drone flights, research on ice movements and snow characteristics as well as small particle sampling out on the ice. Follow me on a tour through the first week of the second icecamp!

 

Monday 29 May - first day of the 2nd icecamp & setup of instruments

The fog that came in on Sunday eve was fortunately gone by Monday (29 May) before lunch, which allowed us to go out on the new icefloe for setup of instruments and for other ice work. The weather was sunny with winds picking up during the day. In the morning, Oden was moored onto the icefloe (see the photo below of one of the mooring lines). It was important that we all get our instruments and sites setup on the ice today because of the weather front approaching us in the evening, bringing us snowfall and strong winds associated with the low-pressure system over Svalbard.

 

Oden is moored onto the icefloe – ready for the second icecamp (29 May).

 

After the moorings, the installation of the permanent sites could begin: the ROV site (see also posting "First ice camp and polarbear visits - Part 2" posted on 24 May) the deployment of the SIMBA buoy (Prof. Timo Vihma's buoy from the Finnish Meteorological Institute; the buoys measure the mass balance and temperature of snow and ice down to 40 cm. Instruments and batteries of the buoy are stored in a yellow box and then buried under the snow. Timo is holding the ice drill in one of the photos below and the locations of the SIMBA buoys are shown in orange in one figure below) and of course the setup of our met-alley with the meteorological fluxmast and the radiation stand. Equipment was craned onto the ice and snow scooters were used for transportation of all equipment to the sites - only the polarbear guards were allowed to drive the scooters. Once on the scooters, the scouting for the best locations of the different sites was performed. Again, the ROV site was placed near Oden as limited by the length of the cable. Our met-alley was placed this time a bit closer to Oden, approximately 350 m from Oden. The SIMBA buoy was placed 300 m further away from the met-alley towards the center of the floe.

 

Set-up of the met-mast at met-alley on May 29th.

Set-up of the radiometer stand at the met-alley on May 29th.

Sonja, Theresa and Heather sitting in the sled behind the scooter ready to go on the ice! (May 29)

It was a beautiful day, despite the cold winds, and temperatures were around -5 degrees C. With a lunch break on Oden, for the four of us in our met-team; it took us about 3 hours to setup the met-alley (see photos above; met-mast with our flux instruments and the radiometer stand with upward and downward looking radiometers on the tripod). In the last photo above you can see me (in front), Theresa Mathes (in the middle; PhD student from Technische Universität Berlin; measuring aerosol fluxes and part of the work-package "Aerosols and clouds in-situ"; more below in a sub-chapter) and Heather Guy (in the back; from the University of Leeds; part of our met-team) sitting on the sled behind the snow scooters ready to go on the ice!

 

When the craning of equipment and instruments onto the ice was completed, the Helikite was allowed to operate. Scientists interested in measurements close to the open water headed to the edge of the icefloe after lunch. More about Jessie Creamean's (Colorado State University) work on ice particles and Penny Vlaho's (University of Connecticut) work on ocean acidification at the ice edge in coming blog posts.

Sea ice dynamics & buoy program

 

Prof. Timo Vihma (left) and PhD student Truls Karlssen (right) during the deployment of one of the seven drift buoys. (16 May)

Denis Demchev (from Chalmers University of Tech. in Gothenburg) is the work-package leader for a group of scientists onboard Oden interested in studying sea ice dynamics, e.g., how the sea ice moves and deforms and how the ice deformation features like ridges (when two icefloes drift towards each other) and leads (when two icefloes drift away from each other) are formed and how they appear on satellite radar images. He and his colleague Truls Karlssen from the University in Tromsö (UiT; see photo above) hope to be able to use observations of sea ice dynamics to validate comparable satellite observations for a better automatic interpretation of the images. Apart from the information of ice movement and deformation, the drift buoys also measure waves in the ice for a complete picture of the ice dynamics. They also collect in-situ snow samples at each icecamp and during some helicopter ice stations to study snow characteristics. This is important when analyzing satellite radar images during the melt season, as melting snow affects dramatically the radar backscatter from the sea ice.

 

Buoy deployment plan for Denis' and Timo's work-packages. Courtesy to Denis Demchev.

 

On Monday afternoon, an ice drift buoy was deployed towards the middle of the icefloe. On the figure above you can see the location and deployment times of all 7 drifting buoys (blue triangles) deployed during this expedition (last 3 were deployed at the current icefloe; upper right in the figure), as well as the location of FMI's SIMBA buys (orange circles). Unfortunately, one of the drift buys lost signal and they had to go for a buoy-rescuing operation on Thursday later in the week. The last buoy was deployed by helicopter operation on a neighboring floe (in the figure bottom right) approximately 1.5km from Oden. The last SIMBA buoy will be deployed on another icefloe with thicker ice for completing the joint buoy program between the two work-packages between Finnish meteorological institute and Chalmers University of Tech. (Sweden) and University of Tromsö (Norway).

Measuring small particles on the ice

 

Theresa standing in front of her instrument on Monday (29 May) evening. 

 

Sonja and Theresa making snow-angels after a successful evening on the ice. Photo by: Niklas Vestin.

Being part of an international expedition with scientists of different expertise and interest areas has a lot of advantages: you learn so much new things, new collaboration ideas arise and new friendships are formed. After dinner, I was happy to join Theresa Mathes (on the photo above) out on the ice to retrieve her Condensation Particle Counter (CPC) instrument that she deployed on the ice in the morning. A wind sensor, an air inlet measuring small aerosols and a temperature sensor are placed on a lift that measure these parameters at different heights from the surface up to around 130 cm above the surface. Her lift is attached onto a 2m high tripod (see photo) on top of which she has a 3D wind sensor. For her instruments to work properly, her lift with the inlet needs to be directed towards the wind. Furthermore, it is highly important that the air upwind (to the direction where the lift is directed at, i.e. from where the wind comes from) is clean, i.e., no snowmobiles or people walking there that could disturb her particle measurements. Her particle counter runs for around 4-5 hours, which requires constant maintenance of battery change, checkups, data downloading and refill of isopropanol few times a day. I was happy to join her this evening (and several other times during this icecamp) for the evening checkup. Theresa has also a condensation particle counter for flux measurements attached onto the formast on the ship with a higher measurement frequency (20 Hz).

Such a beautiful weather! The weather was, unfortunately, about to change for the next couple of days, limiting the work on the ice.

Tuesday & Wednesday 30-31 May - snowfall and low visibility

A thick cloud layer approached us late on Monday evening. In the morning (Tuesday 30 May) the snowfall together with stronger northerly winds decreased the visibility and all scientists that wanted to go out on the ice had to be on standby for a gap in the weather. There was a short break in the snowfall after lunch on Tuesday, which allowed me and my colleague Heather (together with two snowmobiles and two polarbear guards) to go out on the ice for battery change at met-alley. We had to be quick and effective due to the bad visibility and the danger of polarbears. Most of our logger boxes and cables were covered in snow, but we had no time to dig all of them out! The snowmobiles were left on during the battery swap to scare off polarbears. After less than 30 minutes we were back onboard.

The snowfall and northerly winds (15 m/s) continued until Wednesday (31 May) and all ice work was cancelled before lunch due to the bad visibility. The sky started to clear up during the afternoon and different ice work was prioritized. Priority one were battery swap at the met-alley (as our instruments will not run longer than maybe 30h) and work at the ROV site. The clouds passed and sunny weather conditions allowed for work on the ice close to Oden in the late afternoon. Again, I was happy to be able to join Theresa out on the ice in the evening - and it was soo beautiful! The photo below is taken during the evening trip to the ice on Wednesday (31 May). Out on the ice, the ice felt like a big sand beach with "sand" blowing over the surface - but of course it was snow blowing with the wind over the snow-covered ice surfaces. The temperatures dropped down to -7 degrees in the late evening and it felt quite cold outside with the northerly winds. Fortunately, the winds were calming down and the sunny weather was going to continue during the next day, meaning a busy work-on-the-ice day! The second photo below is taken in the midnight, where you can see the path from the snowmobiles to the met-alley.

We were continuously drifting southwest with the icefloe but were still (for another 3 days) above 80N.

Evening scenery out on the ice after the snowfall. (31 May)

Path from the snowscooters to our met-alley. (31 May)

Thursday 1 June - busy ice day

Drone operations

Today was the perfect weather for working on the ice: sunny and calm winds, no fog and no polarbears. The ship was turned towards the wind in the morning (for the aerosol measurements) and Oden was re-moored onto the icefloe. The Helipod was operated in the morning and all kinds of different ice operations were conducted throughout the day. For example, Denis went out to search for his lost drift buoy and I was happy to join Timo Vihma (Prof. at the Finnish Meteorological Institute (FMI)) and Gabin Urbancic (researcher at FMI) to help out with a first attempt of thermal mapping with drones. Black and yellow reference markers were equally spaced á 40m between the SIMBA buoy and the met-mast, along which the drone was flying and taking infrared photos for the thermal mapping of the surface. Additionally, the snow depth was measured together with Denis at each marker - and it was quite varying from 20 cm to 60cm snow depths along 340 m transect! Potential for a new method of estimating snow depths based on thermal photos from drones was tested for the first time today. In the photo below, you can see Gabin operating the drone. Drone flights are also used for vertical profiling of the lowest atmospheric layer above the surface and can be operated either from the ship or from the ice. As for other operations, there are limitations for drone flights: drones are sensitive for strong winds, fog and precipitation, as well as compass uncertainties due to high latitudes and magnetic interference when operating drones from the ship. Until now, Gabin has managed 46 scientific flights with the drones, both for vertical profiling, surface measurements as well as for taking photos and videos.

 

Gabin operating the drone in the evening (May 31).

Afternoon ice-work

Later, Heather and Michalis arrived at the met-alley with the sled filled with batteries to be swapped with the old ones. I joined them and had the pleasure to stay out on the ice for 4 hours this afternoon! I could also feel that summer was on its way - the snow glittered and regions of partly wetter snow were visible from the sun's reflections on the snow surface. These could turn into melt ponds (shallow "lakes" of melted snow within the snow-covered sea ice in the summer Arctic) very soon as soon as the melting begins. Due to the snowfall the other days, we had no time to clean our instruments before today. Some boxes were completely snow-covered and it took some time to carefully dig out all cables and boxes from below the snow (see photo below). In case of suitable wind directions so that pollutions from the snowmobiles do not affect the aerosol measurements at the front of the ship, snowmobiles could be used for transport of batteries (and scientists) between the different sites and Oden. On the photo below, Michalis (part of our met-team and PhD student and colleage of mine from Stockholm University), me and Theresa are sitting on the sled with batteries behind us that are on their way back to Oden to be charged for the next day.

Snow-covered boxes and cables at the met-alley (Thursday 1 June).

 

Michalis, Sonja and Theresa returning to the ship after a successful day (1 June) out on the ice. The batteries are loaded in the sled ready to be taken back onboard to charge them for the next day.

Oden was drifting quite a lot in the afternoon and the mooring-lines started to tighten. There was a high risk that the mooring lines would de-attach from the ice. We were asked to get onboard and the lines were removed. For the rest of the day, Oden was not attached onto the floe but was kept at the floe by engines and then drifting around the floe during the night when no ice work was conducted.

In the evening, we were all gathered with our jackets and blue hats on the helideck for a group photo, after which there was a science talk. Going to the sauna after this long day felt really good!

Friday - Saturday 2-3 June - frosty and foggy conditions

The wind turned northerly and there was clearly a change in the weather to come over the weekend. According to the forecast, the surface temperatures should have reached the melting point (zero degrees) this weekend. Of course, it felt a bit weird that the atmospheric river that we had been waiting for so long would come from the north (where the air is cold and dry) instead of from the south (with warmer and moister air). Part of the air reaching us over the weekend came from Canada and part from Kara Seas to the east of us - and the air floes were then merged together when they arrived over Oden. The air was still relatively warm and moist, and surface temperatures reached up to -1.5 degrees C, but unfortunately did not make it all the way to the melting point. Weather models tend to have a warm bias (too warm temperatures), which could explain the overestimation by the forecast models of the surface temperatures for this weekend. This just shows the potential for improvements and the importance of our observations to improve the models. So the melting did not begin yet - and we need to be patient and hope for a melt onset for the next week!

 

Change in the weather ahead! Helikite is flying from the aft. Photo taken on Friday morning (2 June).

Friday (2 June) morning was sunny and frost was seen on many instruments. The clouds approaching us in the horizon (see photo above) indicated a change in the weather - and this was also captured by the Helikite operations (see also the Helikite on the photo). Ice work was conducted in the morning as the visibility was still good. However, in the afternoon, bands of fog travelled over the sea ice, the sky became cloud-covered and it was snowing lightly, lowering the visibility. Due to too much drifting with the icefloe and the tension it caused on Oden, all ice-work in the afternoon had to be aborted while Oden needed to be re-moored onto the icefloe. The icefloe became more and more unstable and it was unclear whether or not we could stay at the floe. Satellite images revealed that large parts of the original icefloe a week ago had disappeared - only a fifth of the floe was remaining!

 

Foggy and cloudy conditions on Friday (2 June) evening, when we visited the met-alley.

Cloudy skies continued for the rest of the day, decreasing the visibility. Oden was able to re-moore onto the icefloe in the evening and selected ice-work scientists were let out on the ice after dinner. The view at the met-alley (see photo above) was completely different compared to yesterday!

Oden was moving in the night, breaking a neighboring icefloe to stop it from pushing towards us and returned to the icefloe the next morning. Weak northerly winds continued through Saturday (3 June) and the weather changed quickly from sunny to partly cloudy and occasionally foggy, thereby varying the visibility. The amount of people and the time working on the ice were minimized due to the weather conditions - and there was always at least one snowmobile out on the ice for a sudden evacuation.

The formast was lowered down to remove the icing of our instrument (3 June).

Ice work was conducted in the morning as usual - however it had to be suddenly interrupted because of a white cute visitor - a polarbear! Again! I think it was the 9th polarbear we have seen during this expedition so far! So the weather was not only challenging for ice work, but also polarbears. And this fellow one was not the only polarbear we saw the coming days, but around 3 new polarbears each day! Staying at one location for already a week lures polarbears from far away - and with the northerly winds our smell travels downwind to polarbears that live closer at the ice edge (which is to the south of us) and thus they start to follow that smell and approach us!

More about the second icecamp and the several (per day!) polarbear visits in the following posting.