#CryoVEx2014: ONR/MIZ Camp 2: Stars, icing fog and a lot of measurements!

STARS! I had never seen stars while on sea ice before.  Usually my trips start in early May when the sun is up around the clock.  This is by far the earliest I'd been out on the ice and it was spectacular to see stars and aurora over the sea ice.

STARS & AURORA BOREALIS

 After an excellent warm nights sleep we would contact the MIZ/ONR camp managers in Sach's Harbor, have a nice warm breakfast consisting of some oatmeal and coffee and plan what we would do that day. Before we could start work we also had to check the fuel drums for the heaters and top them off.

Nothing like the smell of diesel first thing in the morning. Fueling the drums that feed the heaters.

Since the P3 had overflown us the day before we decided to try using our ground based LiDAR system in the 400m by 60m survey grid.  LiDAR or Light Distance And Ranging uses a laser to take measurements of distance.  The laser is turned around its base and scans up and down as well.  Then known the horizontal and vertical angle of each scan point, and the time it took to send a laser pulse and get the reflection back to the surface you can get the distance to the surface.  From this information and by tying it into our grid and drill hole data we can create a 3D map of the snow surface, with very high spatial resolution (lots of detail).

Setting up the LIDAR scan

We knew this could be a real struggle because the LiDAR system is not a fan of cold temperatures and the temperature in camp was hovering around -30C but was warming up.  The LiDAR survey uses some dedicated reflectors placed at known points and heights above the snow surface to tie the other measurements together. By moving the scanner around and leaving the dedicated reflectors in place you can scan from multiple places in the grid to fill in shadows created by hills.

Here we setup a grid about 150m by 60m and were planning to scan it about 7 times or more before moving two of the reflectors and scanning a new section. We set out all the reflectors and then brought the LiDAR out of the tent and onto the pole. Chris programmed up the LiDAR and showed it where the dedicated reflectors were and then just as it was going to start scanning, it shut down because it was too cold.

Let's try that LiDAR scan again

After warming the LiDAR up in one of the tents we tried again, even faster this time, and we got one scan in before it shut down because it was too cold.  The day continued like this and eventually we completed 5 scans of this first area.

Me measuring snow depth along the center line while Chris and Bruce run the LiDAR scans. As hard as we try to minimize our disruption of the snow surface there is no getting around some disturbance due to walking out the corner reflector, the LiDAR, the center line, and the edges of the grid.

The other thing we did that day was to deploy the Seasonal Ice Mass Balance Buoy that Bruce Elder had brought up from CRREL.  This buoy measures snow depth (or ice surface melt once the snow is gone), and ice bottom position (draft) changes allowing us to measure the change in ice thickness/mass.  It also has a temperature string with a temperature sensor every 10cm and this model even two light sensors to measure the amount of light coming in at the surface and the amount of light penetrating through the snow and ice to the water. With the experience we all have we can deploy one of these buoys quickly and orderly and did so during one of the pauses we took to warm the LiDAR back up.

Chris, Bruce and I finishing up the seasonal ice mass balance buoy installation.

We did some quick drill hole, snow depth and survey laser measurements of the grid while Chris and Bruce started taking the LiDAR out again. This took up the rest of the day.

Shot of the camp skidoo in front of my tent in the evening.

 The next day we decided to measure snow depth grids within our 400m x 60m grid.  We had
a 400m by 60m survey grid at 5m spacing and then if time allowed we would conduct a detailed 1m spaced grid around each corner reflector. The 5m spaced grid went by very quickly, it is only 1053 measurements (81 60m lines and 13 measurements on each line).  It was nice to be using the MagnaProbe.  This device and automatically record snow depth by measuring the position of a magnet that moves up and down on the outside of a probe that you stick into the snow.  You just stick the probe in, the magnet sits on the top of the snow and then you press a button and the snow depth and GPS data are recorded.  It is a fair bit faster than using a manual probe and writing down numbers.  However, I did find the MagnaProbe to be a bit dull for my taste, both in terms of probe sharpness and the mind numbing repetitiveness of the measurements.

The probe's magnet is contained in a relatively large plastic basket which is used to keep the magnet on the top of a soft snow surface.  On sea ice, the snow is usually topped with a hard windblown layer called "wind slab" (I know, very creative). The diameter of the plastic basket was a bit to large for my preferences, as it could be hard to measure snow depth on the edge of a snow drift, it just took a bit more thought about where exactly to place the probe and basket so that the probe and magnet would be over the correct place.

But back to the story, it was an overcast day with low clouds and not great visibility so we were not expecting any airplanes to come.  Once we began measuring we also found out that the low fog was right at the point of icing, especially with all the work of probing.  Furthermore there was a strong cold breeze, so anytime I had to walk into the wind I was conscious of not getting frost bite, and facing out of the wind I was getting very warm.

An icy selfie. Hard to hold the DSLR far enough away.

 By the end of the day we were all growing snow and ice from our jackets as the sweat and break and moisture from our skin made its way through the layers to the outside of our jackets.

An icy Christian. 

 The ice build up became a bit of a problem as the ice was starting to coat the MagnaProbe causing the basket to stick on the probe instead of sliding down between measurements. It got to the point that I needed to wipe the ice off the probe nearly every measurement.

Me looking rather icy, not needing the Canada Goose jacket right now as I'm doing the 5m grid and working hard. Note the poor visibility.

 The icing fog coats everything cool with what we term rime. Sensors and weather stations can be confounded by riming and in extreme cases the build up of rime snaps cables, and topples weather stations.

The top of the seasonal ice mass balance buoy with rime (from the icing fog)

We completed the measurements and of course we were excited to see the results so that night and over the next day we started working up the data.  Lucky we have a rugged field laptop that warms its hard-drives up before turning on and has a big battery and energy efficient processor. So first up is the 400m by 60m grid that we measured with 5m point spacing.I've converted each measurement to a pixel and coloured the pixels according to snow depth from 0 to 120cm. This is sort of like looking down at the surface. I've also scaled the plot so that its dimensions are approximately in scale. It looks pretty interesting, you can see some large drifts around (0,0; the bottom left) and a drift extending from (400,30; middle right edge) towards (260,30).

The 400m x 60m snow depth grid measurements.

We had decided to do a 40m by 40m grid with 1m spacing centred around each of the corner reflectors.
Here are the two grids. The first one goes from X=20m to 60m on the 400m grid above. The second one goes from about X=336.8m to 376.8m on the 400m grid above (so near the left and right ends, respectively. Note that I've changed the colour scale so that now snow depth goes from 0 to 75cm instead of 0 to 120cm in the 400m grid graph. This is just to bring out the smaller details of the grids below. What you can see is that the second corner reflector was sitting in a region of generally deeper snow than the first corner reflector.

Okay, so that is probably a long enough post. Up next: other airborne passes over our site, saying goodbye to Camp 2, moving to Sachs Harbour and onwards to Resolute Bay and Greenland.

CryoVEx 2014: ONR/MIZ Camp 2

First thing each morning and at 1930 each evening we would call back to Sachs Harbour to let people know we were alive, to report weather and visual conditions, and to learn various plans for the day as it pertained to the different groups. 

With our successful day yesterday we were ready to move on to Camp 2 and were really hoping that the British Antarctic Survey (BAS) team was ready to move to Camp 3; our morning checkin confirmed this to us.

One of the only issues we had the day before was that our ground based electromagnetic induction sensor, the EM31 was not working.  This sensor measures the distance between itself and conductive layers underneath it, so we use it to measure the total snow plus ice thickness.  The sea ice is salty but relatively non-conductive, sea water though is very conductive and so it returns a signal to the sensor. It is a nice way to fill in the spaces between our manual drill hole measurements.

During our morning check in we asked for our backup EM31 to be flown to us. We had one sitting in its shipping box, and the empty shipping box from the one we took on the ice, guess which case we got?  The BAS Twin Otter showed up from Sachs Harbor first to drop off buoys for the BAS team while the Ken Borek Twin Otter went to Camp 2 to drop off the rest of our equipment and to pick up the BAS team.  The EM31 case on the BAS Twin Otter was the empty shipping case.  We made a few phone calls and quickly had the right box thrown onto the Ken Borek Twin Otter to be brought to Camp 3 for a quick survey.

Arrival of BAS team from Camp 2. 

Above you can see us eagerly greeting the Ken Borek Twin Otter, hoping that the EM31 was on it, and it was.  The plan we developed was to slowly offload the BAS team and then slowly load up our stuff so that Christian and Bruce would have time to quickly use the EM31 on our survey lines.  The first problem was that our EM31 was at the bottom of the gear pile from BAS, and the second problem was that everyone was WAY TOO HELPFUL and was putting gear on the plane very quickly (not something I would normally worry about).  In the end it did not matter anyways, we asked the pilot for some extra time to survey the line but as luck would have it, this EM31 did not work either!! The first unit had been for maintenance and calibration just before the survey and the second unit was a rental! What was going on?! We had no choice but to pack up and move on to Camp 2. It was another cold windy day, you could see frost nip developing on people very quickly so we were all trying to play close attention to each other's faces.

After a short flight to Camp 2 we immediately set to work.  This was to be our main camp complete with a dedicated survey grid and overflights by NASAs Operation IceBridge, our AEM system below a Ken Borek Basler (retrofitted DC-3), and the DTU Twin Otter carrying ASIRAS, an airborne version of CryoSat-2. As aircraft overflights could start immediately we set about building the radar corner reflectors we had made and shipped up.  These reflectors strongly reflect RADAR waves back to the sensor that sent them (i.e. from ASIRAS). Because it was a cold windy day we built the reflectors inside as there really is not much worse than working with small metal pieces in -20C with a strong wind.

Putting together the 1m corner reflectors inside the cooking tent. Nothing is worse than working with small metal parts in a strong wind at -20C.

We braved the elements outside to build the stands as they were rather large to fit into the cooking tent.
I was glad I had marked the wood and predrilled the holes because it was a snap to put them together.

Putting together the corner reflector stands.  I had mocked these up once in Edmonton, pre-drilling all the holes, and labelling each piece of wood so that everything would fit together nicely and quickly.

The plan that we had agreed to with various other scientists (such as though involved with the NASA IceBridge Campaign was to install the corner reflectors approximately 360m apart, within a 400m x 60m measurement grid.  The grid would be in the middle of a 2km long measurement line where we would put out buoys and visual markers to help align the aircraft over the measurement grid.

Christian's sketch of the site layout with the grid, transect, buoys, camp and runway shown.

We setup one edge of the 400m survey grid and then worked up the center line and finally the outer edge.  We often use bamboo poles as markers as they are light and very strong. The reflectors were setup and then the transect was laid out.  We could nicely use the corner reflectors and the grid markers to line up our transect. Then using a handheld GPS we placed the ends of the transects about 800m from each edge of the transect.  AS you can see in the sketch above we actually ran out of space on the eastern edge of the transect due to a large lead, but we were still 700+ meters away from the start of the grid. One of the issues with using the handheld GPS to place the ends of the transects, and one of the general issues when using GPS for sea ice work is that the sea ice may be drifting.  At Camp 2 were were drifting some 800m/hr! So one of our transect legs was about 15m shorter than we planned. Measuring the 800m with tapes or ropes would have taken much much longer than just running them out and using the GPS for measuring the distance.

Christian standing proudly by the first corner reflector.

This was basically the rest of the first day at C2 as we only arrived around 2pm or so.
We had a simple dinner, though excellent (thanks for doing most of the cooking Christopher!, I especially loved the grilled cheese sandwiches!).

Enjoying a warm beverage during a well earned break.

The next day it was time to start measuring. We started by measuring the edges of the transects that extended from our survey grid.  The main idea was that we would delay measuring in the survey grid until the NASA P3 flew overhead (and hopefully the other planes as well) or as late as possible.
We started with just 5m spacing along the transects measuring the snow surface elevation with the construction laser, the snow depth. We also did drill hole measurements of ice thickness and bulk snow density measurements every 50m.

Around 1300 local time we stopped for a quick lunch break and heard the noise of a plane...it was the NASA Operation IceBridge P3. We watched a few passes and took a few photos but then went back in for lunch so that we could continue our measurements in the afternoon.

The NASA P3!

It seems that our garbage bags work well for directing the plane, as do the buoys which the NASA team could look at until take off (and even receive positions of on their Iridium phones). It also helped that the ice was drifting in the same direction as our survey transect was set up.

A DMS image of the survey line markers and corner reflector taken from the NASA P3. Credit: Dennis Gearhardt/DMS and Michael Studinger/NASA.

In all the P3 flew 10 passes over our survey line before continuing on with the rest of the days flight mission. It was great to see the P3.

Maps of the overpasses of the P3 flight. Credit: M. Studinger/NASA.

 We finished the afternoon with the second transect leg and called it a day at around 7pm.
Well that is all for todays post.  The next post will continue with Camp 2 as there's still so much to talk about!

To the Ice: ONR/MIZ Camp 3

Finally, after a little difficulty we managed to get to Sachs Harbor.  We spent just one night there, in the house of the owners of the guest house as the guest house was full. Jackie and Roger were really nice to let 4 of us stay there, our last real beds for a week, also the last chance for a shower (which I failed to take).

The camp were were going to on the ice is part of a research project called the Marginal Ice Zone Project and involves researchers from the US, UK, France, Canada. and includes the US Office of Naval Research.  The camp managers/logistics operators were from the University of Washington Applied Physics Lab in Seattle., a couple of guys, Adam and Jim , I know from CFS Alert where the joined the Operation Switchyard Project. Adam is an engineer working with underwater gliders, and his dad is actually a rocket engineer and has had rockets go to all of the planets in our solar system (HOW COOL IS THAT).  Adam is also very involved in outreach (lucky kids in Seattle, he has such cool stories and projects).  He was also one of the people onboard a Twin Otter that crashed through the ice in 2010 North of Alert, the first year I was in Alert, but I digress


We were up early the next day, ready to head to the ice.

The sun rising while we are loading the plane. Chris Hiemstra is waiting patiently.

Because of the time of year and Sachs Harbor's latitude, we had hours of this wonderful pinkish light during sunrise sunset, and loads of "blue hour" and "golden hour" light, very pretty.

Loading the Ken Borek Twin Otter to take us to the ice.

The Twin Otters we use in the Arctic are probably my favourite smallish plane. They can carry a lot of equipment for their small size due to large wings and overpowered engines.  They are also able to take off and land on incredibly short runways, such as sea ice floes.

We had a 1.75hr flight west from Sachs Harbor to Camp 3 where we would spend a couple days maximum doing some measurements before heading to our main site and Camp 2.

Views of Sea ice

Sea ice

As we approached Camp 3 the visibility steadily decreased but lucky for ice another Twin Otter from the British Antarctic Survey had already landed, and the runway was marked out with garbage bags.

First Sight of Camp 3

We landed and right away dumped our bags off and started doing measurements.  We were hoping to only spend one or maybe two nights at Camp 3, depending on the progress of the team that was at Camp 2.

Chris started out taking snow depth measurements with the MagnaProbe, an automated snow depth tool that logs your readings automatically and has a GPS antenna integrated.  I won't get into the details of how it works but all you do is turn on the logger and gps, stab the probe into the snow and press a button and wait for some confirmation beeps.

Bruce was drilling holes in the ice and taking measurements and Christian and I were taking measurements of the snow surface elevation using a survey laser. We shared this job because it goes much faster with two people.

Christian holding the laser detector.

While surveying we noticed a crack was starting to form in the ice that we were crossing. After watching the crack for about 5-10 minutes, we decided to keep measuring on the other side of the crack but to return periodically to check on the crack. Luckily the crack was not developing very quickly and even when we left the next day was still less than 1m across.

A crack in the ice developing along our survey line. The markings on the tape are spaced 1m apart.

We finished one line of measurements and then stopped for a snack before completing a second line of measurements across a different ice floe.  The first measurements were done going out from the end of the runway and the ice was regular first year ice, very flat and rather boring.  The second line crossed MYI and also included a couple of ridges. 

When we came back from our second survey line there was a problem, the heaters in all of the tents had gone out and another guy who was spending the night with us was unable to get them going again.  I finally realized that there was a gap between the fuel and the stove in the fuel line, and that the fuel barrels had not been vented and had created a large vacuum as they worked.  I went out back and vented the barrels and after a bit more work we got the first stove lit.  In the next tent, where I was sleeping, the camp setup people had left some paper under the stove, and when we were warming the bottom of the stove up before lighting it, we caught that paper on fire, again I quickly snatched up the paper in my gloved hand and threw it outside.   

That evening we moved our gear into our tents where we would spend one night.

Bruce and Christian's tent

 Mine and Chris's tent.

These Arctic Oven tents from Alaska Tent and Tarp were GREAT! They were strong, spacious and we had them luxuriously appointed with cots, cot pads, sleeping bags, overhead nets and a diesel drip stove.  With the stove, the tents were downright hot.

Usually when I head to the Arctic in May, 24 hour daylight is pervasive and all you notice is a bit of dimmer light at night, now though, the sun was fully setting so I had my first spectacular sunrise and sunset over Arctic sea ice. 

Well that concludes the Camp 3 blog post.  We move on to Camp 2 in the next post.  Here we spent a few days so perhaps there will be a couple posts on that sight.  Heck, maybe even some data plots.

CryoVEx: Catching up

It has now been a couple of weeks since I wrote a very quick and short blog post in Sachs Harbor. I indicated I would write and post some blogs but really I did not have time.  Now I am sitting on the bus from Calgary to Edmonton, just a few more hours until I am home for the first time in 26 whole days and I am sure looking forward to sleeping in my own bed.  I have decided to use this time to write a post or two trying to fill you in on what I have been up to for the past 26 days, and it is harder than I expected.  The days have blurred together already so you will just have to excuse some repetition.

On Monday March 12, I met part of the team (Chris Hiemstra, Christian Haas, and Bruce Elder) at the Edmonton International Airport. We journeyed to Inuvik with First Air, one of the few airlines to still offer a hot breakfast to economy class passengers.

The team arriving in Inuvik. Photo used with permission from C. Haas.

We spent a couple days in Inuvik waiting to be picked up but there was a misunderstanding and no one sent a plane from Sachs Harbor to pick us up.  

Sunset from hotel room in Inuvik.

We ended up chartering our own plane to take is to Sachs Harbor where we spent one night before heading out onto the ice. 

Our King Air Beech Craft airplane chartered from Aklak Air that took us from Inuvik to Sachs Harbor

The team inside the King Air plane excited to finally be heading to Sachs Harbor (though not thrilled about the cost of hiring a plane for this purpose).

I have posted previously about our time in Inuvik and our trip to Sachs Harbor, here, here, here, and here.

Okay, that is enough for one post.  Since I am only 35 minutes into my trip home, I will write a few more blogs though I may schedule them to post automatically and regular intervals.