On the Ice

The End of the Field Season

So, the last week of this field season went and got itself in a big hurry, so much so that I’m no longer on the ice as I write this last post for our 2013-2014 field season.

There was a station that we had removed earlier in the season that we wanted to reinstall, Emma AWS. Originally, our last scheduled day to fly to this new site was Saturday 8 February. When Saturday came and went, we were put on the schedule for either the next Monday or Tuesday, whichever was a better weather day.

Unfortunately, the weather at Emma’s location was poor on Monday, but we did try flying to a different station, Vito AWS. As (bad) luck would have it, there were too many low clouds and fog at the site. We flew around, surveying the area, for about a half hour. The clouds were moving too quickly, so any opening we did see would soon close up before we could land. We never saw the station, and had we landed it would have been very difficult to see with the fog. We turned back to McMurdo.

Since we flew on Monday, that left Tuesday for us to snowmobile out to Windless Bight AWS to raise the station. There was a lot to do to prep for the trip: get the cargo ready and out to the snowmobiles by Scott Base, get some cargo supplies from town like a sled and survival bag, then load up everything. On top of this all, we had recently found out that Willie Field AWS, a station a few miles out on Pegasus Road, had some issues with the pressure readings that we needed to go check up on. It was feasible for us to visit Willie before Windless in the same day, and that’s what we did on Tuesday.

The sled Lee towed on the back of his snowmobile

The sled Lee towed on the back of his snowmobile

Of course, we weren’t able to fix everything on the first visit to Willie, so we had to go back on Wednesday. But before that we still had to do our work at Windless. We needed to raise the station, and that involved digging out the battery box, removing the instruments and upper-most tower section, then installing an additional tower section below the original. So the station went from about 7 feet high to 17 feet.

Driving out there was actually quite enjoyable. It was sunny, which I think makes it worlds better than driving when it’s cloudy because you can actually see the surface. Plus the scenery looks better.

Looking back at town and our tracks when we arrived at Windless Bight AWS

Looking back at town and our tracks when we arrived at Windless Bight AWS

Lee scoping out the station. It definitely needed to be raised; there was at least 3 feet of snow accumulation in one year.

Lee scoping out the station. It definitely needed to be raised; there was at least 3 feet of snow accumulation in one year.

Clouds started rolling in a couple hours into our work. It started innocently enough, with the sun being blocked for a few minutes at a time. Then the sky was completely overcast. Eventually, we noticed that land features on the horizon would go in and out of view, an indication that there was snow around. With about an hour of work left, the wind started picking up (at *Windless* Bight, of all places!) and flurries started falling.

Lee attaching the instrument boom, with the skies completely overcast.

Lee attaching the instrument boom, with the skies completely overcast.

We kept plugging away, and when we were just plugging the last of the instruments in, it started snowing. Lightly at first, but it became quite heavy, with a strong northeasterly wind (I believe). When Lee climbed up the tower to get measurements of the instruments, the tape measure was whipping and snapping in the wind, and it was very intense.

The completed Windless Bight AWS. At this point, I just wanted to take this quick picture and get out of there so we could make it back to town.  The best indication of the weather in this picture is the fact that you can't make out the horizon at all.

The completed Windless Bight AWS. At this point, I just wanted to take this quick picture and get out of there so we could make it back to town. The best indication of the weather in this picture is the fact that you can’t make out the horizon at all.

We radioed in to McMurdo to make sure the weather was good enough for us to travel in. They said it was good in McMurdo, but that it wasn’t going to get any better at Windless for a while. We are fairly certain that it was Condition 2 weather when we left (mostly due to visibility; the visibility was less than 1/4 mile). The thought crossed my mind whether we were going to have to open the survival bag and pitch a tent for the night. Since we could still see the flags marking the route back to McMurdo (thank goodness for flags!) we decided to give it a shot and head back.

For the first 5 or 10 miles of the ride, all we could see were the flags marking our route and a slate of white. It was an interesting feeling. The winds were blowing the snow across our sleds, and at times I could hardly see Lee as I followed him because of all the fresh snow he was whipping up. Eventually the sun shone through the clouds, though the snow still fell. As we got back on Pegasus Road, the snow stopped and there were only high clouds above. We even saw what appeared to be a snow devil on the horizon. That was sweet! We couldn’t get close enough to get a good picture of it though. When we parked our snowmos, we noticed some sun dogs!

Sun dogs on either side of the sun

Sun dogs on either side of the sun

So, when it seemed like the drive back to town would be stressful, it was actually almost as enjoyable as the ride out. One part that was tiring, though, was walking back to town from the snowmo depot. It took us a little over an hour, as we carried our bags and trekked up the hill with our cold weather gear on. This was made especially difficult because it was already at the end of a 12-hour day. It was long, but it was well worth the work.

Once we got the problems fixed with Willie, we had to pack all of our stuff into our orange shed for storage over the winter, as well as clean our lab and our dorm rooms. The work never seemed to end! But we got all of that done, and on 13 Feb, the day before we left, there were some incredible mirages, fata morgana I believe, on the horizon.

Fata morgana, evident above the ship on the horizon. The mountains definitely do not look like that!

Fata morgana, evident above the ship on the horizon. The mountains definitely do not look like that!

Our day of redeployment finally came on Friday 14 February, and of course Antarctica had one more trick for us. It snowed pretty much all day, but fortunately our plane was still able to take off.

Lee, in the foreground, and everyone else boarding the LC-130 for the flight north to Christchurch, New Zealand. You can see the snow, but the plane was still able to take off with no difficulty.

Lee, in the foreground, and everyone else boarding the LC-130 for the flight north to Christchurch, New Zealand. You can see the snow, but the plane was still able to take off with no difficulty.

After about 7.5 hours, we landed in Christchurch! It was an overall smooth way to end a relatively successful field season, if you ask me.

I had a great time on the ice this year. It was good to spend more time in Antarctica. I got much more experience doing our weather station work, and as a result got many more cool experiences under my belt. And this year may forever be known, for me, as the year of the penguin. After not seeing any last year, I got my fair share of penguin sitings this year and then some!

With that, I’ll sign off on the blog for the 2013-2014 field season. It has been fun keeping you all updated on things, and I’ll be doing the same when I’m on the ice again next year!

Cheers!

Dave

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The Storm

At the end of my last blog post, I was updating you all on conditions from the storm as it was happening. It was very cool to be able to experience some intense Condition 2 weather in McMurdo. It’s amazing how quickly the visibility had dropped, and by how much. Here’s a picture from inside Crary, looking south toward the helo pad and the open water… But note that the open water is barely visible.

Condition 2 from Crary

Condition 2 from Crary

It stayed like this for an hour or so, then the snow let up and the visibility improved. The storm was far from over, though. The wind was relentless, and continued even into the next day. Here are a few pictures of the waves caused by the storm.

The snow stopped but the wind didn't. An iceberg got lodged near the shore.

The snow stopped but the wind didn’t. An iceberg got lodged near the shore.

Hut Point, with the wind still whipping and the waves still crashing. Some snow accumulated on the point, but most of the white you see is ice formed from the spray from the waves.

Hut Point, with the wind still whipping and the waves still crashing. Some snow accumulated on the point, but most of the white you see is ice formed from the spray from the waves.

Later in the night, the sun poked through the clouds and highlighted the waves.

Later in the night, the sun poked through the clouds and highlighted the waves.

Those last two pictures of Hut Point were missing one very important thing: the Vessel. Due to the unusually large expanse of open water around McMurdo, the waves were larger and more powerful than normal and caused the ship to jostle in the pier enough to destroy it. It wasn’t safe for the ship to stay there, so it had to leave town. This is unfortunate because not all of the cargo from McMurdo had been loaded onto the ship. This may have a negative impact on many groups, as people here are trying their best to get all the cargo shipped. It just goes to show how much of an impact the weather can have down here, from us not being able to land on the ice shelf, to winds generating powerful waves that cause the departure of the Vessel.

To end on a positive note, a few days ago an Adelie penguin wandered into town. It was amazing that it got so far into town, given all the hustle-bustle of the area. One would think it wouldn’t want to be so close to so many unusual objects and creatures (humans).

An Adelie in McMurdo!

An Adelie in McMurdo!

Cheers!

Dave

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Ferrell AWS and Weather Cancellations

Back on 6 February, Lee and I finished our helo work for the season with our visit to Ferrell AWS. Earlier, we thought we had finished the helo work at Ferrell, but we’ve had difficulty with the freewave transmissions there. It seems as if that spot is a dead zone for VHF (very high frequency) transmissions, which are what freewave uses. When we landed, our helo pilot was trying to contact McMurdo via VHF radio but was unable to, even though he could see the repeater he was aiming for. This seems to be exactly what is happening to us with our freewave transmissions to White Island!

We want the Ferrell observations to be available realtime, so the purpose of our trip back was to reinstall the Argos antenna we had removed earlier this year. Lee, Jonathan Thom back in Madison, and I worked up a way to have both freewave and Argos transmissions at one station the day before we flew. It was all very last-minute, but fortunately it ended up working out.

Ferrell AWS, with freewave and Argos transmissions installed (the white vertical pipe is the Argos antenna)

Ferrell AWS, with freewave and Argos transmissions installed (the white vertical pipe is the Argos antenna)

One reason we were able to get out to Ferrell by helo on such short notice is because our fixed wing flights have been getting canceled due to weather. It’s tough when the weather here in McMurdo is good, but out on the ice shelf it’s too cloudy to land. We look out the window and think, how the heck aren’t we flying? But Antarctica is a big place.

The past couple days, we’ve been able to see (and feel) exactly why we’ve been canceled. There is a storm just north of us that is producing very heavy winds in our area. One night, the winds were whipping up the open sea water onshore. I don’t think the couple pictures I took did them justice.

Big waves at McMurdo

Big waves at McMurdo

The winds have been too strong for planes to take off, and not just for the smaller, Twin Otter planes. Even off-continent, redeployment LC-130 flights are being canceled. Some of our friends in other groups were scheduled to leave the ice yesterday but were canceled due to the winds. Their departure date has been bumped back a few days, as flights that were supposed to leave today (yes, they got canceled too) were full of passengers with higher priority to depart.

Now we sit and wait for the weather to clear in McMurdo. This downtime does give us the opportunity to start packing away our gear for the winter. Hopefully Monday will bring clear skies and calm winds so we can service at least one more AWS by Otter.

Cheers

Dave

PHOTO UPDATE!

It’s started to snow in McMurdo…

The view of the Chalet from Crary, just outside our lab. Definitely a no-fly day.

The view of the Chalet from Crary, just outside our lab. Definitely a no-fly day.

An update on the weather, from the McMurdo intranet homepage:

The weather in McMurdo and surrounding area. Condition 3 is good weather, Condition 2 is worse and Condition 1 is the worst. No outside travel is permitted in Condition 1 weather.

The weather in McMurdo and surrounding area. Condition 3 is good weather, Condition 2 is worse and Condition 1 is the worst. No outside travel is permitted in Condition 1 weather.

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We got to Margaret AWS!

Lee and I took the Otter to Margaret AWS today, Monday 3 February. This station was installed in 2008 and had never been visited since. We knew that it was due to be raised, for two reasons:

One, with stations that we’ve installed on snow, it is almost always the case that there is snow accumulation, by precipitation and/or blow and drifting. The amount of accumulation depends on the location; some stations can get up to a few feet each year, and some don’t get any. If we know approximately how much snow an area gets a year, we can estimate how often we need to visit a station to raise it given the height of the instrumentation.

Two, the ADG (Acoustic Depth Gauge) instrument we have on Margaret recorded a height of about a half meter (1.5 feet) above the surface a few months ago. Many of our stations have this instrument, and it is a good way of knowing exactly how close the instruments are to getting buried. The ADG sends a pulse of sound waves towards the snow surface and measures the time it takes for that pulse to bounce back and reach the sensor. The longer the pulse takes, the higher the ADG is off the ground.

Knowing that we have to raise the station is half the battle. The tricky part is actually getting there (especially in Margaret’s case). It is by Roosevelt Island, on the Ross Ice Shelf about 500 km (310 miles) due east of McMurdo (a 2.5 hour flight). In this region, low cloud cover occurs often and in abundance (my previous blog post touched on this, when we visited the WISSARD fuel cache). I don’t know how many times we’ve been scheduled to go to Margaret this season and got canceled due to weather, flying somewhere else instead. We were pleasantly surprised to hear that Margaret was a go today. We flew across the shelf (a pretty boring flight, scenery-wise) and arrived at the station to be greeted by clear skies overhead.

Margaret AWS, upon arrival

Margaret AWS, upon arrival

The ADG is the instrument on the lowest “arm” that extends to the left at the bottom of the station. It was indeed low, as we expected, so we got to work right away on preparing everything to be raised.

We weren’t sure whether we should try to install a 7-foot or a 10-foot tower section to raise the station, so we brought both and made a game-time decision. We determined that the tower was tall enough to only warrant a 7-foot tower section. We felt that the 10-footer would have been too tall and that station may not have remained stable.

Unfortunately, the 7-foot tower section wouldn’t fit on top of Margaret. One, or both, of the tower sections was slightly skewed such that we could only fit 2 of the 3 poles of the tower section on at one time. After a few minutes struggling with it, Lee and I decided to give up on that and raise the instrumentation on Margaret’s current tower section. We probably won’t be able to wait 5 years until the next visit, but the instruments should be high enough for a few years’ time.

Margaret AWS, after we raised the instruments

Margaret AWS, after we raised the instruments

Things didn’t go exactly as planned, but we were happy to get the instruments raised and have a successful trip to Margaret. We don’t take any flights to that region for granted!

An update on life in McMurdo:

The population has increased a bit in the past week, and ships have been in and out of the port. Now, the vessel is in town. For the next week, people in town are working tirelessly to unload the cargo from the vessel to supply McMurdo with food and other vitals for the next year. Once that’s all unloaded, cargo from McMurdo that needs to be shipped back to the US gets loaded on. This includes everything from science equipment to food waste. As you may imagine, it is a long operation. The weather is also starting to cool down here. Highs have mostly been in the low 20′s, and winds are starting to increase. This past Saturday night, it even snowed. It was fairly heavy for a bit too. It’s actually starting to feel like Antarctica again!

"McMurdo Station Antarctica," the Vessel, and snow-capped Hut Point behind it.

“McMurdo Station Antarctica,” the Vessel, and snow-capped Hut Point behind it.

Cheers!

Dave

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An interesting way to reach Sabrina AWS

The Twin Otter work continued on Wednesday 29 January, as Lee and I were scheduled to reinstall Tom AWS, the one we had removed on 24 January. This AWS was to be moved to a new location. In our communication with the Otter pilots and flight coordinators, we had been referring to this new site as “New Tom AWS.” As Lee, Melissa, John and I were discussing this Tuesday night, Melissa came up with the idea to rename the station Emma AWS, after her and Tom’s 1-year-old daughter (Tom AWS was named after Melissa’s husband). We talked it over with the rest of the AWS crew back in Madison and determined that the new location of the station was far enough from the original to warrant a new station name, as it would probably show some unique weather to the original.

So on Wednesday morning, Lee and I shuttled out to Pegasus. We took off at about 9:30 am. Our first destination was the WISSARD fuel cache on the far side of the Ross Ice Shelf from McMurdo. The fuel here is meant for flights like ours: a long journey to and from McMurdo that couldn’t be made without refueling. This area of the Ross Ice Shelf is notorious for having bad flying weather, typically in the form of low clouds and fog. This is exactly how it was when we landed.

The edge of the low clouds and  fog outside WISSARD

The edge of the low clouds and fog outside WISSARD

These clouds make it very difficult, if not impossible, to see the snow surface when landing. Instead of risking that dangerous landing, we flew past the edge of the cloud bank and landed in clear skies, then taxied to WISSARD for about 5 miles. That’s a long way to taxi, but it’s much safer than the alternative. When we arrived, there wasn’t much to see.

Tanks of fuel at the WISSARD fuel cache

Tanks of fuel at the WISSARD fuel cache

Of course, there is usually more to see than initially meets the eye. As we were filling the plane up with fuel, I was taking in the foggy landscape. The sun was dulled by the clouds, and the sky and ground almost blended into each other. Looking away from the sun, the clouds were thinned out a bit, and I could see some of the sky. Looking exactly 180 degrees away from the sun, I saw the faintest of fogbows.

The very faint fogbow. I used a slight image enhancement to accentuate the feature, as it was difficult to capture on camera

The very faint fogbow. I used a slight image enhancement to accentuate the feature, as it was difficult to capture on camera

We departed the cache and headed for the coordinates where we thought Emma AWS was to be installed. As we were flying, Lee and I noticed that we had started going over the Transantarctic Mountain range, rather than staying over the ice shelf and flying along the mountains. We thought this was weird, but put this thought aside and enjoyed the scenery.

It was just as breathtaking as it was when we flew over them after we removed Tom AWS.

The Transantarctic Mountains

The Transantarctic Mountains

We flew along a glacier valley and reached an area that had some flat fields of snow, indicating a potential landing sight. The pilots did some investigating before landing the plane for good, though. Since this was a sight that had no records of being landed in before, it was important to determine the characteristics of the snow surface. As we circled the area several times, we noticed some spots that obviously had crevasses; these areas are way too dangerous to land on. There was an area that appeared to be crevasse-free, but the snow surface still needed to be characterized. To do this, the pilots dragged the skis of the Otter along the surface. This allowed them to get a feel for how the Otter reacted to the snow and see what the tracks looked like.

The open field of snow and the ski-marks from the Otter

The open field of snow and the ski-marks from the Otter

After a couple ski-drags and a few more fly-arounds, we all decided that this wasn’t a safe place to land. Though that field we were testing may have been crevasse-free, the snow was far too soft. On our last ski-drag test, we noticed the Otter start to sink too deep into the snow as we slowed down. It may have been very difficult to take off again had we come to a complete stop and did a couple hours of work.

We turned around and headed back out to the ice shelf. Fortunately, Lee and I were prepared to do some planned work at Sabrina. The wind propeller wasn’t functioning, so we were going to replace it.

Upon arrival at Sabrina, it was pretty obvious why the wind propeller wasn’t functioning.

Sabrina AWS upon arrival. The wind propeller and nose cone had broken completely off.

Sabrina AWS upon arrival. The wind propeller and nose cone had broken completely off.

In addition to repairing the anemometer, we raised the lowest temperature sensor and replaced the data card.

The updated Sabrina AWS

The updated Sabrina AWS

We were on the ground at Sabrina for about an hour, and quickly got on the Otter and departed for the 3 hour flight back to McMurdo. It was a long, stressful day. It turned out that we had the coordinates for Emma AWS wrong by one degree latitude. It sounds insignificant, but it was the difference between landing on the sturdy, flat Ross Ice Shelf and attempting a landing on soft Transantarctic Mountain snow. There are two consolations to this mix-up: we were able to get to Sabrina AWS, and we still have just over a week’s time to get back out and install Emma AWS.

An Antarctic field season never ceases to surprise!

Cheers

Dave

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The Improbable Twin Otter flight to Tall Tower! AWS

On Tuesday 28 January Lee, myself, and two riggers (Andrew and Emily) did something that I thought only happened in fairy tales. We took a Twin Otter out to Alexander Tall Tower! AWS. Now, an Otter had already been out there to pick up Ben the Kiwi. No way, I thought, was there a chance that the weather would cooperate enough to get us out there a second time in the same season. Sure enough…..

The much talked about, seldom visited Alexander Tall Tower!

The much talked about, seldom visited Alexander Tall Tower!

Our goal was to have the riggers raise the lowest three levels of instrumentation, while Lee and I would raise the power system by digging it out and reinstalling it back on the surface. You may be thinking, “Why do the instruments need raising? It’s a tall tower (100 feet at initial install, now about 90 feet) so the instruments must be high enough from the surface.” You would be partly correct. There are 6 levels of instrumentation. Referring to the picture above, each of the horizontal bars is a level of instrumentation. The top three are pretty high above the surface, but the bottom three are bunched near the surface and are at a higher risk of getting buried. The riggers did a great job raising these, saving them from the wispy grasp of blowing snow for at least another year.

The lowest three levels of instrumentation, after being raised

The lowest three levels of instrumentation, after being raised

Lee and I had our work cut out for us. The power station was installed three years ago, and hadn’t been raised since. There is about 1.5 feet of snow accumulation each year at Tall Tower!, so the bottom of the station was 4.5 feet deep plus the amount it was buried upon installation, which could have been a few feet. We needed to dig 8 feet down!

The power system. We had already started digging a bit.

The power system. We had already started digging a bit.

The things we needed to dig out:
The solar panel framework
Three guy wires with deadmen anchors
Battery box
Cable connecting the power system to the tower

Our first plan of attack was to dig out the battery box(es). We weren’t sure whether there were one or two. The top few feet of snow was fairly powdery and easy to shovel. After that layer, the snow became more compacted. The tricky part was around 5 or 6 feet down, when we ran into a layer of ice.

Eye-level view from the first pit I dug. The surface is at Lee's waist.

Eye-level view from the first pit I dug. The surface is at Lee’s waist.

Shortly after we started digging, I decided to go for one of the deadmen while Lee continued to reach the battery box(es). The deeper I dug, the more the “digging” became stabbing to break up the hard snow and ice, the pieces of which I would shovel out. It became exhausting. The guy wire never seemed to end, and when it seemed as though I would never reach the deadman, I struck metal. The relief was short-lived, as there was even more ice built up around the deadman, and its length (about 2 feet) was greater than I anticipated. It’s difficult to describe how good it felt to finally break it loose.

Yes!

Yes!

I had gotten two of the guy wires and deadmen out, and Lee was still digging for the battery box(es) and the third guy wire, when we had a conference with everyone to determine whether it was reasonable for us to try to dig out the whole power system. We decided it wasn’t; there was far to much digging to do. Given John and Melissa’s success snowmobiling to the site, it helped make our decision to hold off with the power system raise until next season. We can set up a 3-day camp then and complete the rest of the digging. Before we left, I wanted to make sure we got all of the deadmen out.

The power system, with all three deadmen dug out

The power system, with all three deadmen dug out

Lee pulled out the last deadman from the pit, and the way in which he did it couldn’t have been better. I had chiseled it out from the ice and snow, and it just needed a good hard yank or two to get out. Lee was holding the guy wire and was standing at the top of the pit, yanking away. I was watching as I saw it coming looser and looser. On the last yank, Lee had tugged so hard that he lost his balance and fell backward…..into the first pit I had dug. The riggers were watching and instantly burst out laughing, as at one moment they saw Lee and the next he was out of sight. Fortunately, he wasn’t hurt. We had filled up the hole about halfway with some chunks of snow that we had dug out from other holes. It was a funny way to say so long to Tall Tower!, until next year.

Cheers!

Dave

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Helo to Ferrell and Lorne AWS

The busy-ness (ha!) continues. Our days have been filled with work this week, which is always welcome down here. Things can get boring pretty quickly if there isn’t any work to do. I’m squeezing in this blog post so I can keep up with the work that we’ve been doing. If I wait too much longer, this information will be too old to post!

This past Monday, 27 January (Lee and I both agree that that feels WAY longer than 2 days ago), we flew by helo to Ferrell (install freewave transmission) and Lorne AWS (station check up). It was a relatively easy day for fieldwork.

We arrived at Ferrell, and the first thing we needed to do was install the freewave antenna.

Lee getting the freewave antenna ready to be installed. That small tower section on the far left is the old Ferrell AWS.

Lee getting the freewave antenna ready to be installed. That small tower section on the far left is the old Ferrell AWS.

When installing the antenna, we needed to make sure it was angled slightly away from the surface so it could hit White Island AWS. Ferrell AWS was beginning to lean, so mounting the antenna with a normal bracket caused the antenna to point into the ground. We brought a bracket in which we could angle the antenna correctly and got it installed.

Ferrell AWS upon completion. Notice the angled black antenna on the right of the station.

Ferrell AWS upon completion. Notice the angled black antenna on the right of the station.

We verified the freewave transmissions were working and hopped on the helo to go check on Lorne AWS (the helo stayed on site with us as we did our work).

We were unsure whether Lorne AWS needed to be raised or not. To our delight, the station height looked good, so all we really needed to do was remeasure the instrument heights.

Lorne AWS, with Lee and our helo pilot Ryan on the left.

Lorne AWS, with Lee and our helo pilot Ryan on the left.

Once that work was done, we could head back to McMurdo. Piece of cake! One advantage to doing helo trips is they’re (inherently) quicker than Otter trips, so it doesn’t take an entire day to do a couple stations’ work. On Monday, we left McMurdo at around 9:15 am and returned around 3 pm. When we did return, we spotted some welcome visitors on some ice offshore!

Some Adelie penguins hanging out on broken sea ice.

Some Adelie penguins hanging out on broken sea ice.

A digression: Good news arrived to McMurdo the night prior (Sunday 26 January) in the form of John, Melissa and Suz (if you’re keeping track at home, Ben the Kiwi had already made it back to town a few days sooner than the rest)! They returned from their 12-day camping trip out at Tall Tower! AWS, and they were all in good spirits. Based on their experience, it seems like snowmobiling out to Tall Tower!, rather than taking the Twin Otter, is the way to go; it’s much more reliable, as we would be able to depart practically whenever we wanted because we wouldn’t be hindered nearly as much by the weather. As far as John and Melissa’s science work is concerned, they were able to get it all completed successfully. An overall great trip for them!

Back to the original subject: With Monday being a success, our work with helo travel was completed. It’s all Otters for us from here on out (except a snowmobile trip or two). Lee and I flew by Otter yesterday and today, and I’ll reserve those fun stories for the next couple blogs.

Cheers!

Dave

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Twin Otter flights to Lettau AWS and Tom AWS

It’s been another busy week as we visited more AWS. On Wednesday 22 January and Thursday 23 January Lee and I flew by Twin Otter fixed wing aicraft to Lettau AWS, on Wednesday, and Tom AWS, on Thursday. Wednesday was my first flight on a Twin Otter, so I was eager to get flying. But, of course, it’s not as simple as hopping on the plane and leaving.

There is more time and preparation that goes into flying by Otter than by helo. All the cargo, aside from the literal passengers and some small bags, needs to be entered into the cargo system. Then, as opposed to departing right from McMurdo as you do with helo, the Otter departs from Pegasus airfield. The cargo needs to be ready out there when we want to fly, so we need to enter it into the system at least 2 days before we fly. We find out if we’re on the schedule to fly the night before flight date. Around 7 am the following morning we get a call from fixed wing ops whether we are a go or we have been canceled. If we’re a go, we need to catch the shuttle out to Pegasus, which leaves McMurdo at 8 am. The time between the call and the shuttle can get hectic. That shuttle ride is about an hour, and it takes about an hour to prepare the Otter for flying (loading cargo, fueling up, etc). And finally, inherent in Otter flights is that the travel time to AWS is almost always longer than helo because we only use the Otter for AWS that are too far away for the helo to reach. I’ve now discovered that all these factors add up to very long work days when flying by Otter.

Lee and the Otter, preparing to depart Pegasus

Lee and the Otter, preparing to depart Pegasus

The flight to Lettau took 2 and a half hours. It’s a great time for reading, taking a nap, or enjoying the sights.

Length aside, it’s always great to get to AWS, especially when we get one working again like we did at Lettau. Our goal was just what we accomplished: install the enclosure and get the station transmitting again via Argos. All the instrumentation was already on the tower. The only additional thing we needed to do was raise the lower temperature sensor about a foot. There isn’t usually much accumulation there, so that usually makes servicing easier.

Arrival at Lettau AWS

Arrival at Lettau AWS

Me, securing the enclosure

Me, securing the enclosure

Lettau AWS upon completion

Lettau AWS upon completion

On Thursday, we flew to Tom AWS. We had ambitious goals for this day; we wanted to remove Tom and reinstall it at a location nearby, but far enough away to measure data unique to the original location of Tom. This flight took just over 3 hours, and considering how long it usually takes to remove and install an AWS, our plans had us pushing right up against the Otter pilots’ duty days (the number of hours they can work in a day; I think it’s around 14 hours).

We arrived to Tom AWS at 1 pm and got to work right away. This was a full removal, so we needed to dig out the tower section, batteries, and the dead men attached to the guy wires.

Arrival at Tom AWS

Arrival at Tom AWS

There was more accumulation and many more layers of ice than we anticipated, so the removal took too long. It was the only thing we could do that day. We also had to cut our time there short because we needed to stop at a fuel cache along the way back to McMurdo to refuel. All four of us, myself, Lee and the two pilots, ended up digging the station out. Each of the holes (4 total) ended up being about 5 feet deep. One consolation to the rapid and tiring work was that we successfully removed it all.

Proof of the successful removal

Proof of the successful removal

It was time to head back to McMurdo, first stopping at CTAM (the Transantarctic Mountains Field Camp) to refuel. The scenery was stunning. We flew along and over the mountains for the hour-long flight to CTAM.

The Transantarctic Mountains

The Transantarctic Mountains

IMG_2854 - amrcblog

IMG_2860 - amrcblog

IMG_2875 - amrcblog

When we got back to McMurdo around 9:30 pm, we ate a late dinner (24-hour pizza, yes!) and then got some shut-eye.

Cheers!

Dave

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Helo to Linda AWS

Lee and I knocked off another station on our to-do list when we flew by helo to Linda AWS yesterday, 20 January (I suppose you could consider this part of the helo bonanza). We needed to dig out and remove the old instrumentation, raise the station, and install new instrumentation. We also wanted to set up freewave transmission for it, but we were prepared to use Argos transmission if the freewave failed and we couldn’t connect to White Island. The weather was great, with clear skies at McMurdo. At Linda we were on the edge of some high clouds, and there was only a slight breeze… Excellent working conditions.

The helo leaving us at Linda AWS

The helo leaving us at Linda AWS

Once they left, we got right to work. We set up our GPS instrument to get the coordinates for the site, then started digging. We needed to remove a couple of buried instruments, a lower temperature sensor and a junction box. This proved slightly more difficult than we first anticipated due to a layer of ice that had formed around the instruments. Once we recovered those, we could free up the cables for the removal of the rest of the instrumentation. The next order of business was to install the 7-foot tower section. Once that was installed, we put up the new instrumentation.

Our working area, with Lee on the tower installing instruments

Our working area, with Lee on the tower installing instruments

The high clouds started slowly creeping overhead, so we were glad that once we got all of the instrumentation secured, we were able to connect right away to freewave. It was just about as painless an attempt as one could imagine!

The completed Linda AWS

The completed Linda AWS

The new instrumentation we installed are (from top to bottom) an anemometer, temperature sensor, solar panel, freewave antenna, relative humidity sensor, acoustic depth gauge (measures snow height), pyranometer (radiation sensor), an infrared sensor to get the snow surface temperature, the enclosure including a pressure sensor, and last but not least a battery box to power the station.

I’ll close this post with more penguin photos! These were taken Sunday night, 19 January. Some folks from POLENET, the science group we share an office with in Crary, said they saw 4 penguins on the ice near McMurdo. I got my camera and went down to be treated to many more than 4! I watched them for about an hour, and at one point one hopped on shore about 25 feet away from me.

Adelie penguins. We saw them swim along the shore too!

Adelie penguins. We saw them swim along the shore too!

I had just sat down to view some penguins in the distance when this guy hopped up on shore

I had just sat down to view some penguins in the distance when this guy hopped up on shore

Adelies, with Mt Discovery as a backdrop

Adelies, with Mt Discovery as a backdrop

Cheers!

Dave

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Helo trip to Pegasus! (And Ferrell AWS)

And so continues the helo bonanza. On Thursday 16 January we were planning to helo out to Ferrell AWS to switch the data transmission from Argos to freewave. Of course, all of these flights depend on good weather, and Tuesday and Wednesday were beautiful days for flying. On Thursday, however, there were some low clouds apparent on the satellite imagery to the east of White Island, which is where Ferrell AWS is located. This didn’t bode well for a helo landing, as the surface becomes nearly impossible to define when there are low clouds over ice. Lee and I arrived at the helo pad, talked with the helo techs and decided that we would take the trip out there and determine whether it was safe to land upon arrival.

There were only high clouds in the McMurdo area, but a few minutes after we departed we started seeing the low clouds. They became thicker and more widespread as we approached Ferrell.

Low clouds, as seen from the helo. The surface became completely obstructed from view the closer we got to Ferrell. The clouds did have a cool, hill-like appearance though.

Low clouds, as seen from the helo. The surface became completely obstructed from view the closer we got to Ferrell. The clouds did have a cool, hill-like appearance though.

A few miles from Ferrell, we decided that it was unsafe to land so we turned around and headed for McMurdo. Over the intercom, Lee said to me that now we could go to Pegasus AWS and finish up work there, as we would have time to take a shuttle from McMurdo. The pilot and helo tech heard this and said, “Why don’t we just drop you off at Pegasus?” We said, “Why not!!”

Lee and I arrived to Pegasus in style. Most often, to get to Pegasus from McMurdo you would take a shuttle, and the drive can take an hour or more. It’s funny to think that Lee and I took a helo from McMurdo, to Ferrell, then to Pegasus in about the same amount of time as a shuttle ride to Pegasus.

It was very generous of the helo guys to drop us off. It saved us a lot of time and gave us a chance to eat our flight lunches in the Pegasus galley. Once well fed and rested, we headed out to our AWS to finalize the freewave transmissions there.

Pegasus AWS, with White Island (where we are directing our transmissions) in the background

Pegasus AWS, with White Island (where we are directing our transmissions) in the background

As we were waiting to verify the transmissions were successful, I noticed a very cool cloud feature on the horizon near White Island. It’s called Kelvin-Helmholtz instability, and it occurs when there is a velocity and density difference across two layers. This can result in a wave-like cloud structure as it did for us that day.

Kelvin-Helmholtz wave clouds

Kelvin-Helmholtz wave clouds

Once we were done admiring that spectacle, we verified that the freewave transmissions worked at Pegasus. After several trips to the station, we finally diagnosed the problem and fixed it successfully. We then headed back to the airfield to catch a shuttle to McMurdo. On our short drive to the airfield, we were treated to the always-welcome sight of four penguins, seemingly on a journey somewhere.

Four Adelie penguins at the airfield

Four Adelie penguins at the airfield

On Friday 17 January, we (continuing the helo bonanza) flew out to Ferrell AWS. This time, the weather cooperated. The skies were clear between McMurdo and Ferrell and beyond. The only very minor issue was the wind; it wasn’t too windy but it was constant as we worked. At Ferrell, we wanted to switch the data transmission to freewave. We also noticed that the lower temperature sensor was buried, so while Lee was fixing up the freewave antenna, I dug out the sensor to be raised.

Ferrell's lower temperature sensor

Ferrell’s lower temperature sensor

Unfortunately, after trying to adjust the direction of the antenna and attempting to connect via the laptop, we could not establish a connection between Ferrell and White Island AWS. We will have to visit the station again; fortunately, the helo schedule is pretty open, so we are actually on the schedule to do this visit sometime next week. For now, Ferrell is still transmitting via Argos.

Ferrell AWS after we did our work

Ferrell AWS after we did our work

Today, Saturday 18 January, we were hoping to yet again continue the helo bonanza to Linda AWS, but we got canceled due to weather. It is far too windy (~60 mph winds at Black Island, which is on the way to Linda). Hopefully we can get there next week.

More updates as they come.

Cheers

Dave

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