Notice the bit of sunlight on the side of my face!

The main station and sunrise. This photo was actually taken a day before “official” sunrise. In actuality, the sun takes a several days to rise.

On station, we have begun the large list of tasks posted by our station manager which mostly involve shoveling out buildings that have been dormant for the winter, and performing deep cleans of bathrooms, hallways, and work areas. I’ve decided that I have spent enough time inside so I volunteered for a few shoveling tasks namely the cargo office, cargo DNF (the building that houses cargo waiting to be sent out or received that can’t be frozen), and a summer camp Jamesway tent. The FEMC (Facilities Engineering Maintenance and Construction) crew is probably the busiest group with the station opening work as they have to get fuel to all the buildings and start heating them up so they are ready when the summer folks arrive. Our heavy equipment operators are busy as well removing snow and beginning to smooth out the skiway for the first flights. They have had a little bit of trouble due to the cold temperatures because they cannot operate the bulldozers under certain temps.

The BIF (Balloon Inflation Facility) is just below the Sun. To half cylinder shaped buildings to the left are the Jamesways that are being dug out and warmed up for the summer crew.

At ARO, I’m just finishing up inventory to figure out what needs to be shipped down during the summer. It is mostly unchanged from last year because we haven’t had many problems with the instruments this year so there will probably just be a few items to alert people back at ESRL in Boulder, Colorado about. We are also at our intensive ozonesonde launching period where we are launching every 2-3 days as opposed to our normal one per week. It’s been rather unexciting in the depletion department this year. It seems that the polar vortex may not be all that well defined as some years with very low ozone levels. A description of the process of the annual ozone layer destruction over Antarctica can be read in my previous post, “The Ozone Hole: It’s Still There!” Once the sun is a little higher in the sky, we will be able to resume daily measurements with the Dobson Spectrophotometer (measures total column ozone through the atmosphere).

The solar instruments have also been placed back on the roof and are collecting data again. Initially they were having trouble with the -90F temperatures, but we have seemed to iron out the problems and they are now tracking the sun well. For an overview of the solar instruments, see the previous post, “As Sunset Approaches, Let’s Talk Solar Radiation”.

The roof of ARO and various solar instruments.

The next thing that is on tap for myself is organizing all of the flask samples that have been taken over the winter and getting them ready to ship out in the summer. Mostly that just involves writing up the paperwork so it’s ready to go for my replacement (yay paperwork!). Oh, and packing. The thing I look forward to least is also on the agenda. I will need to find boxes to ship home all the things that have kept me entertained here such as my Playstation 3 and movies. As well as excess clothing that I don’t want to travel with.

As I mentioned in “The Ozone Hole: It’s Still There!”, I will be posting an ozonesonde launch with the plastic balloons that we use. Don’t worry, I haven’t forgot! I have it videotaped and will get it posted soon!

Here are some more nice pictures during the last month or so:

The Moon and Venus. The were the last two visible objects in the sky as the sun was closer to coming above the horizon.

ARO from halfway between the station and ARO

The Moon over the Clean Air Sector, directly opposite of the rising Sun.

Nice reflection off the corner of ARO

The Moon about to set out over SPT (South Pole Telescope)

The atmosphere has four main layers which are the troposphere (the lowest layer in which most weather occurs), the stratosphere, mesosphere, and thermosphere. There is some ozone in the troposphere, but it is a very small amount and is produced by the reaction of pollution and ultraviolet (UV) light. Most of the ozone in the atmosphere is located in the stratosphere, hence the name the “ozone layer”. The ozone layer is important because it filters out some harmful UV radiation. CFCs eventually make it into the stratosphere and mix in with the ozone molecules. The CFCs don’t do their damage until they react with UV radiation which breaks the bond of the chlorine or bromine atom apart from the rest of the CFC molecule. Chlorine and bromine are highly reactive with ozone (a molecule consisting of 3 oxygen atoms) which then breaks the ozone apart becoming a ClO and O2 (regular breathable oxygen). The creation of ozone in the stratosphere is from the interaction of UV radiation with an O2 molecule. It splits the O2 creating two single oxygen atoms which then react with O2 creating O3 (ozone).

Example of the CFC/Ozone destruction cycle from NOAA’s ESRL website

These appear to be processes that could take place all over the world so why is the ozone hole unique to the Antarctic region? There are two main factors that enable a hole in the ozone layer to form over Antarctica: the polar stratospheric vortex and polar stratospheric clouds. Antarctica’s extreme cold temperatures allow for these polar stratospheric clouds to form. The clouds enhance CFC/ozone reaction causing the destruction of ozone to become very effective. The polar stratospheric vortex forms every winter over the Antarctic continent and keeps the air from interacting outside of the vortex. So basically ozone from outside the vortex is unable to flow in and replenish during this time. That is when we see the lowest ozone values. As temperatures warm through the summer, the polar stratospheric vortex begins to break up, polar stratospheric clouds disappear, and the air mixes back into the Antarctic stratosphere replenishing the ozone layer. The filling in of the ozone hole causes a decrease in ozone worldwide which how it becomes a worldwide issue. The ozone hole hasn’t proved to be decreasing yet but the fact that the harmful CFCs look to be working their way out of the atmosphere is encouraging and we look for the hole to begin decreasing in decades to come.

So right now we are at the point where the sun is getting just high enough (still well below the horizon) that its rays are beginning to hit the stratosphere breaking down the CFCs that are up there. At the Atmospheric Research Observatory (ARO) we measure ozone in three different ways. One is with a surface analyzer that gives us a baseline level of tropospheric ozone, and the other two include the Dobson Spectrophotometer and launching ozonesondes which both give us an idea of stratospheric ozone.

Ozone surface analyzers

The Dobson Spectrophotometer. During the winter, observations are only available when the moon is up. Bad weather and poor visibility can hamper opportunities thus making balloon launches extremely important (especially so this winter it seems!).

For most of the year we launch one balloon a week but as the ozone hole forms we start launching two to three times a week. The idea is that we increase the resolution of the data so that we can see the peak of the ozone depletion. The balloons are great because they give us a complete profile of the ozone all the way up to 30-35 kilometers high.

In the winter we launch plastic balloons. The rubber balloons don’t get high enough due to the cold air. (ideally we like to get up to 28-30km).

When there is enough light outside for video, I will take you through an entire launch sequence explaining how we prep the sonde, prep the balloon, launch the balloon and show the software that gives us the profile of the data. We can even compare what a normal “healthy” layer looks like prior to the hole forming to the hole itself.

Part of the Radiation Budget, pulled from the IPCC Fourth Assessment Report. Source: Kiehl and Trenberth (1997).

Carbon dioxide has a carbon cycle much like water has the water cycle. CO2 is emitted and absorbed in numerous ways. Whether it’s a chemical reaction in the atmosphere that changes molecules of CO2 into something else, the combustion of a fossil fuel producing CO2, or the oceans taking in CO2 from the air and depositing it deep under the surface, they all play roles as sources and sinks of atmospheric carbon dioxide.

Figure from ESRL Carbon Cycle Greenhouse Gases Group. The data comes from the Carbon Cycle Network that includes NOAA Baseline Observatories (like the South Pole Observatory) as well as cooperative programs around the world.

The figure above graphically depicts the carbon cycle on an annual basis. The red strip indicates the data that has been gathered over the last 10 years from the South Pole. The waves in the graph are from the seasonal uptake of carbon dioxide by plant life. For example, in the summertime when trees have their leaves, and plant life is not dormant, you see a large dip in CO2 values especially in the northern hemisphere because plants take in CO2 for photosynthesis. Also notice the difference in variation (waviness) of CO2 between the Northern Hemisphere and Southern Hemisphere. This is due to the very large forests in the N. Hemisphere compared to the S. Hemisphere, and the fact that the N. Hemisphere is more populated. Aside from the annual variation, notice the steady rise of CO2.

In previous posts, we’ve looked at some of the instruments at the Atmospheric Research Observatory (ARO) that measure things like solar radiation. At the South Pole, carbon dioxide has been measured for just over 50 years now and there are a few different methods of obtaining a CO2 value.

One of them is using our Portable Sampling Unit (PSU) that looks like a suitcase containing a pump inside. Using the PSU, we walk out into the Clean Air Sector (CAS), turn on the unit, and pump air into glass flasks which are then shipped back to the Earth Systems Research Laboratory in Boulder, CO for analyzing. (I shot a video of the process which can be seen here.)

The second is hooking the same type of glass flask that we use in the PSU to the Through Analyzer. What this does is bottle up a sample using the same sample lines as our third method uses a Non-Dispersive Infrared Detector (NIDR).

The Portable Sampling Unit (PSU). Flask samples with this unit are done once a week. On the first and fifteenth of the month, they are done in conjunction with sampling from the Through Analyzer.

Upper right: The Li-COR Non-Dispersive Infrared Analyzer. Lower Left: A display graphing the voltages recorded over the past four hours. The spikes are the calibration gases measured once every hour.

The NIDR uses an infrared source which is a heated filament that emits infrared radiation around the same wavelength that carbon dioxide likes to absorb (usually around 4.26 µm). This energy travels through two absorption cells, one of which is containing a sample of air from outside, and another that is containing a reference gas from a compressed gas cylinder. A mechanical chopper wheel then alternates between the sample and reference gas measuring the difference in the amount of absorption between the two. Using the difference of the two cells helps negate the problem of changes in temperature and pressure. Changes in pressure and temperature change the density of the sample which would skew the amount of carbon dioxide molecules in the measurement. This is a very useful machine that requires very little maintenance and gives us measurements continuously 24 hours a day, 7 days a week (there is about 15 min of each hour that it measures accurate known amounts of carbon dioxide in other gas cylinders for calibration).

On the right are the three calibration gases and the reference gas.

Here is a comparison of when the winds are in the Clean Air Sector (CAS), and when they are blowing station air towards the Atmospheric Research Observatory (ARO). The this graph is when the winds were from the direction of the station and the graph that follows is when the winds are in the CAS.

As you can see we easily pick up local carbon dioxide when the winds are blowing from the station. Winds at ARO are within the CAS probably greater than 90 or 95 percent of the time which is why it is such a good place to get long term continuous measurements of CO2.

Amundsen-Scott Station at Sunset.

Soon we will begin covering up all the windows on station and other buildings. At the South Pole, there is a Dark Sector where there is extremely light sensitive equipment and can be affected by any stray light coming though windows from the station. Not to mention it is a distraction from the beautiful night skies (or so I hear from winter-over veterans). We also have the flaglines that mark the path out to any of the outlying science buildings set up. They will come in handy when visibility is poor in the dark of winter. It is still in the dusk stage right now so we aren’t seeing any stars or auroras yet. Apparently by the second week in April is when it gets dark enough. I can’t wait to take some pictures! Camera batteries last only 5-10 minutes when it gets really cold and windy here so I’m going to have to make some kind of insulated housing for it pretty soon.

Sunset plus two days from the Atmospheric Research Observatory.

We’ve now fired up the TV series Battlestar Galactica (on Blu-Ray HD!). I had heard good things about it so I bought it last summer (northern hemisphere) thinking I could use a good TV series to get into for the winter. So far it’s keeping us entertained. I do a Thursday showing of three episodes every week to try to make it last through the winter. It’s tough to stop at three! Most of the weeks lately have involved me lifting weights before dinner, and then either playing volleyball, video games, watching Battlestar, or some other TV show/movie. Things are quite routine around here.

We’ve had a lot of windy conditions lately resulting in large drifts right smack in front of the stairs up to the Atmospheric Research Observatory (ARO). I’m sure we’ll be fighting these all winter as they get worse. ARO was built so that it could be raised as the snow drifts build up. It is in major need of being either raised or dug out completely. Hopefully this gets done next summer. It looks like it will be somewhat of a project because all of our instrument and inlet lines heading out in different directions and will have to be dealt with. Hopefully it’s with minimal downtime for the instruments. The wind has also carved out a lot of sastrugi that are wave like features on the surface of the snow. We use to have a nice waking path from the station to ARO but now it’s bumpy. Once it gets pitch dark, I’m sure I’ll be tripping and falling all the time on my walks to and from ARO. I already did just the other day!

Just the other day, we had the cold weather phenomenon of yukimarimos form on the surface. They would all collect in the pits of drifts and sastrugi creating a cluster of little cotton like balls of ice. They are very strange. They almost remind me of the seeds that come from cottonwood trees that drift around.

Yukimarimos piling up on a snow drift.

A close-up of the Yukimarimos.

The Final Flight: February 14th, at 2:30am New Zealand time.

We have just barely over two weeks until the sun sets and temperatures are already starting to drop quickly. The day of station closing, temperatures were around -40F. Today it is the coldest since I’ve been here at -63F, and tomorrow it’s suppose to bottom out at almost -70F. It’s amazing how quickly it drops when that sun gets low. The cold temperatures also make everyday things difficult to deal with. We had an emergency response drill today that took place outside and I volunteer on the fire team. You have to be really conscious about your gear because the SCBA (Self Contained Breathing Apparatus) hoses start to freeze and can crack easily. A fire fighter isn’t much good without a working SCBA. Frostbite is a big concern as well. The fire gear gloves and boots are not insulated for cold and do a very poor job of keeping your fingers and toes warm.

South Pole Station from ARO.

As for the science here at ARO (Atmospheric Research Observatory), not too much has changed. I’m still coming out here every day to check to make sure everything us running as it should be and taking air samples in flasks every week. One thing that is starting to change is our ability to do Dobson observations. The Dobson Spectrophotometer is an instrument that uses sunlight to measure total column ozone in the atmosphere. When the sun is this low on the horizon, there is a lot of stray refracted light that affects the measurements and can give us bad results. You may ask, “How do you take measurements in the winter?” Well this is done by using the reflected sunlight off of the moon. So we are able to take sporadic observations to coincide with our balloon flights through the winter. The solar radiation instruments on the roof will be coming down soon after sunset as well, which will be a small project for us. Here is a brief description of the solar radiation measurements we have at ARO and why we are measuring it.

Incoming solar radiation is the backbone of what drives our climate. Changes in the amount of radiation reaching the earth from the sun can be the difference between being in an ice age or not. It is important for us to know how much radiation is a) reaching the surface, b) what type of radiation it is (wavelength), and c) how much is bouncing back off the surface. This is what’s called the “Radiation Budget” in its most basic form. The “Radiation Budget” involves many other processes but the pictures and descriptions below show how we break down the “Radiation Budget” into its basic components at ARO.

The Solar Tracking NIP (Normal Incidence Pyroheliometer)

The NIP tracks the sun in all 360 degrees. It measures direct incoming solar radiation of specific wavelengths.

Diffuse Pyranometer

The diffuse pyranometer blocks out the incoming direct solar radiation and measures any radiation that is getting reflected and refracted from substances in the atmosphere (or any radiation taking an indirect path to the surface).

Pyranometers

These pyranometers detect all incoming solar radiation both direct and indirect. The two outer ones have filters on them to divide it up into shortwave (UV) and longwave (infrared) radiation.

Albedo Instruments

The “Albedo Rack” is basically exactly the same as the pyranometers except that they are turned upside down. They then measure the amount of solar radiation that is reflected off of the earth’s surface. Roughness and color play a role in Albedo meaning that a smooth surface is going to reflect more than a rough surface, and a white surface is going to reflect more than a black surface.. Therefore, it is important not to disturb the snow under these instruments because we want the natural state of the surface. In addition to reflected radiation, it monitors infrared radiation emitted by the earth.

A more complex version of the “Radiation Budget” or “Energy Balance” pulled from the IPCC Fourth Assessment Report.

As you can see, in the above figure, there is a lot that really goes into the “Radiation Budget” and it is a very complex system. When the solar energy comes into the atmosphere, it can take a variety of paths. It can get interrupted by clouds, gases, aerosols and other substances. Two of these processes in the system we observe at ARO as well such as Aerosols, and Greenhouse Gases which I will talk about in a later post.

Hopefully this explains a little bit what’s behind the solar radiation observations that we take at ARO. The South Pole and Mauna Loa have the longest continuous running solar radiation observations of this kind. It’s extremely important that we understand what happens to solar radiation as it passes through the atmosphere and hits the earth’s surface if we want to gain a good understanding of how earth’s climate works. It is even more important as we try to predict future climates.

Spending a week in New Zealand was great. Christchurch really has a good variety of restaurants to choose from and it was nice to be able to take a shower every day instead of our 2 per week. You also tend to forget how nice humidity is! The South Pole is so cold and dry that it wreaks havoc on the sinuses and skin. Aside from enjoying some showers and food, I was able to meet up with a friend from high school and college in Queenstown. Queenstown is probably one of the most beautiful towns I’ve seen. It’s set right next to The Remarkables mountain range which provides a gorgeous backdrop. I was even able to get a round of golf in at the spectacular Jack’s Point golf course! The R&R definitely did its job and I came back to the Pole feeling refreshed and ready to endure the winter.

When I got back to the Pole, I’m sure my partner at ARO (Atmospheric Research Observatory) was happy. He did not arrive early enough in the summer to take advantage of R&R so he was left to take care of things on his own while I was soaking it up in New Zealand. He must have been busy while I was gone because things looked great when I got back!

A view of Akaroa Harbor.

A paraglider suspended over Queenstown.

A beautiful round of golf in Queenstown!

Another great view from the golf course.

About a week after I returned from R&R I was getting ready to head out to ARO when I sat down and my teeth kind of bumped together. It ended up knocking off a piece of tooth that was repaired last spring. Luckily I was able to grab a quick flight to McMurdo and see the dentist only days before she was leaving the ice! It really would have been annoying having to deal with a broken front tooth for 8 months through the winter. She did a great job on repairing it though and actually looks better than the previous repair job.

It turns out that this broken tooth was a blessing in disguise. On my flight back to McMurdo, I was able to capture some spectacular video of the Transantarctic Mountains. We also went over the Dry Valleys, out over the open water, and then ended with a great fly-by of McMurdo. Well worth the dental work!

A view out of the LC-130 window as we enter the Trans-Antarctic Mountains.

A glacier spilling down through a valley.

Another glacier carving it’s way.

Beautiful blue sky over some peaks and valleys.

The Dry Valleys.

Some broken off sea ice in the Ross Sea.

Mt Erebus.

McMurdo Station Fly-by.

Now as we approach mid-February, people are leaving by the bundles. A little less than 2 weeks ago we had about 250 people on station. Now we are down to about 125. There are 2 more major passenger flights out of here in which we will lose about 80 more people leaving us with about 48 people for the winter. It’s strange having all the open space in the galley during meal times. And it’s only going increase the next several days. Tomorrow is the last day for any outgoing mail, and Monday, February 15th, we have our last flights! The sun is very noticeably lower in the sky and temperatures the past week have been much colder. Today is the coldest day since I arrived here last October at -40F. Hard to believe it’s just about here but it is. Winter!

The entrance to the ARO (Atmospheric Research Observatory).

Those daily tasks that I mentioned mostly just involve going through all the equipment in the station and making sure that it is running correctly. Some instruments need daily adjusting to keep them acquiring good data. Others operate on their own pretty well (look for future posts to go more in depth on what exactly these instruments are and what they measure). Throw in setting up some new instruments, launching two ozonesondes (ozone measuring weather balloons) a week and flask sampling (capturing air to sample in flasks), it keeps one pretty busy especially when not really experienced with much of it.

Help has now arrived as Mark VanderRiet arrived last week and Lana Cohen has arrived today. With a couple of weeks under my belt, I am starting to feel much more comfortable on the day-to-day operations and things seem to be running smoothly for the most part. We’ve shipped most of the sampled air flasks that have accumulated over the winter back to their project locations (due to the fact that there are no flights to ship them during the winter season), and are getting ready to receive the shipment of new flasks and other supplies for the up coming year.

As for life on station, it is pretty incredible how we are living down here if you consider what a remote location this is. The room I was assigned is plenty big for my needs and is pretty comparable to the size of room that I had when I was on the NOAA Ship Fairweather. The recreation schedule here is full. Every night of the week there is something going on in the gym (volleyball seems to be the most popular), and there is a great selection of movies and TV shows in the store. The observatory is a great place to hang out in the evenings too if you want to relax and watch a movie. It also gives you a chance to shoot some evening Dobsons too (the Dobson is an ozone measuring instrument)! And by the way, winning bingo twice in one night is not a good way to make friends around here.

Once things settle down, I’m excited to show you all what kind of equipment we have at the Atmospheric Research Observatory, and what it measures. Hopefully I can get into some of the other projects that are going on down here at the Pole as well. I would think I’ll have time, I’m here for the long haul!