Off the Ice

Well, we made it off the ice! It was snowing as we left, but we are now warmly back in Christchurch, New Zealand.

We flew back on the same type of airplane we flew in on: A U.S. Air Force C-17 Globemaster. Since it's the end of the season, they're starting to send home a lot of cargo, in addition to scientists. We flew home on a plane carrying one of the helicopters back to New Zealand. We watched on the ice runway as they loaded it.
Now, the season is officially over! It has been successful and productive, and now we are looking ahead to 10 months of labwork and analyses on the samples we took. All of our samples are being shipped home on the ocean vessel that will bring them to the U.S. after our return. Then, we'll be on our way back down again next winter!

One Final Weather Delay?

We are currently waiting for our transport to Pegasus Airfield to catch our flight back to Christchurch, New Zealand. We woke up this morning to low clouds and snow, so we are concerned that we will have one more weather delay to our field season!

Since weather has had such a big influence on our field season this year, I thought it would be appropriate to blog about some of the neat weather-related sites we've seen this year.

Lenticular CloudsThis is a cloud formation we saw when we were trying to fly to Cape Crozier. Mt. Erebus is the southern-most active volcano in the world, and it sits on Ross Island, overlooking McMurdo Station. Flying to the penguin rookeries on Ross Island has taken us in a circle around Mt. Erebus. The first time we tried to fly to Cape Crozier, it was very windy! These lenticular clouds form at high altitudes when winds moving over a mountain circulate on the downwind side. If the temperature is cold enough, moisture in the air condenses and forms clouds. They are aligned perpendicularly with the wind and form a lens shape, hence the name "lenticular". Pilots tend to avoid lenticular clouds, because when they form, you know there is wind and turbulence!

Low Ceiling

When we finally made it to Cape Crozier, the weather was nice. By the end of the day, however, a cloud system had moved in to cover Ross Island. When that cloud cover sits very low to the ground, it's called a "low ceiling" because the cloud cover is so dense, it's like having a roof over your head. Above the cloud layer, helicopters can fly, because pilots can see in front of them. But, they can't fly through a ceiling, because all they would see is white (and it's dangerous when your pilot can't see in front of him!). If the ceiling isn't too low, pilots can also fly under it. That was the case when we were at Crozier. We could fly above or below the ceiling, just not through it. Luckily for us, our pilot found a "window", or a break in the ceiling, to get us out of Crozier and above the ceiling. We flew at a higher altitude over the island, where we could see over the clouds. So you can see the ice covering the base of Mt. Erebus at higher altitude, and the low ceiling surrounding it. McMurdo Station is below that ceiling! Luckily, our pilot found a hole in the ceiling on the other side of the island that got us back below the ceiling so we could land at McMurdo. This is what it looked like as we were dropping back below the ceiling. Cloud ceiling above our heads, low-elevation coastal Ross Island below.
Cloud MiragesThis is the view we had last night from our lounge window that looks out over the Ross Sea. The mirage is the mirror image of the mountains hovering just above them! This happens when the air is very pure and dry and there's virtually no wind, like last night. There also needs to be a strong difference in air and ground temperature. Light refraction in cold, dense air causes the reflection to occur in the clouds. The mirage we saw moved throughout the evening. Sometimes the reflection was low, so that the actual mountains and reflection melded together, but they would separate again like you see here.

The same weather system that brought us those mirages are what brought us snow this morning, and we're concerned will keep us from leaving for Christchurch today! We are supposed to transport to the airfield in just a couple hours, so we hope the plane will be able to land and take us back north. Keep your fingers crossed!

Shackleton's Hut

Antarctica has a rich history of exploration. Since the 1800's, explorers have been traveling to Antarctica in search of adventure, scientific discovery, and fame. When we were at Cape Royd's, we were able to visit one of the huts built during that period.


The hut was built for an expedition led by Ernest Shackleton in 1908. Shackleton and his crew traveled to the McMurdo area on what is called the Nimrod Expedition. A lot was accomplished on this expedition. Some members of the crew were the first to climb Mr. Erebus, the southern-most active volcano that is located on Ross Island. Others reached the south magnetic pole (which is not the same as the geographic pole). However, their main objective was the reach the geographic south pole. Four team members, including Shackleton, set off from Cape Royds and forged a new trail towards the pole in the spring of 1908. Almost a year later, in January 1909, they were within 97 miles of the pole. At that point, they realized that they did not have enough supplies to reach the pole and still be able to return to the hut alive, so they turned around, never making it to the pole. It must've been such a hard decision for Shackleton... to turn back and not reach his goal, even after enduring so much hardship for that goal, in order to ensure that his entire party survived. Still, they had reached a point farther south than anyone else had at that point, which was definitely an accomplishment.

The hut from this expedition still stands today, 100 years later. This was their shelter as they prepared for their journeys- their home-base. The hut was not luxurious! It is small, and basically one large room. A few dividing walls inside the hut were made out of food and fodder supply boxes. In addition to sleeping quarters, the hut housed a biology lab, dark room, printing press, kitchen, library, scientific and surveying equipment, and an acetylene gas generator so that they could have lights!


That big, cast iron stove is how they heated the hut, cooked their meals, baked their bread, and melted ice for water. On the shelves, you can see the remains of their food stores: things like tinned meat, dehydrated vegetables, bottled soup, cabin bread. Not too different from the kind of things we eat in the field now!

Shackleton had his own canvas-lined room, but the other 14 men shared the rest of the space. They lived in two-bed cubicles divided by canvas and slept on home-made beds from spare parts around camp.


It's definitely amazing what these early explorers could do! They persevered through harsh conditions with much fewer resources than we have available to us today. They were able to accomplish amazing things for science through their efforts. It really puts into perspective how relatively easy it is for us to come down and do our research using airplanes, helicopters, trucks, solar energy, and polartec fleece!

This is our last day on the ice! We have packed up the lab, shipped our samples, and tomorrow we should be flying back to Christchurch! The season has gone by very quickly, but it has been a successful and productive one.

(Learn more about the Nimrod Expedition by going here.)

Camp Hair Contest Winner

The 5 days have passed, and the votes have been tallied. The winner of the 2008-09 Best Camp Hair Contest is...

JULIA!!!!

Julia celebrates her victory in her "fancy duds", flexing her camp hair power.
Congratulations, Julia!

A Little Bit of Green in Antarctica

As you've seen from my blog, Antarctica is cold, dry, and gray. But, there's one oasis in this polar desert: the McMurdo Greenhouse.

[Photo credit: www.sethwhite.org]

While it looks like any other McMurdo building on the outside (except for the vegetable decorations), inside the greenhouse it is warm, humid, bright, and full of greenery!

[Photo credit: www.sethwhite.org]

Unlike greenhouses in the U.S., the McMurdo Greenhouse is not made of glass. It is too cold for that! Instead, it is a sealed and insulated building, with a giant refrigerator door to get inside. "Sunlight" comes from high intensity discharge lamps, and the walls are covered in reflective foil to increase the light intensity from the lamps. To maintain a proper temperature, the greenhouse is heated by a furnace at night and the lamps during the day.

[photo credit: www.schundler.com]
Because Antarctica's environment is protected by the Antarctic Conservation Act, we are not able to import gardening soil to grow vegetables here. So, the greenhouse uses a hydroponic system to grow vegetables, meaning that vegetables are grown in water instead.

How this works: Each plant is seeded in a "plug". The plug is a short piece of PVC pipe. In the pipe, there's a combination of vermiculite and Perlite (little pellets that you can buy from a company), which give the roots of the plant something to hold onto. The plugs are then placed in the shelves you see in the photo above. The shelves have a circulating reservoir system of water moving through them. The water is heated and aerated, and nutrients are added to the water to be carried directly to the plants growing in the plugs on the shelf. That gives the plant everything it needs! Each day, measurements are made on the water, and the nutrient content and pH are adjusted by hand. All of the water is recycled within the reservoir system for that shelf. There is a separate reservoir system for each type of plant, so water from the peppers doesn't mix with the water for the tomatoes. All of this is maintained by just one person!

The greenhouse grows a variety of vegetables. In the past, we've had lettuce, spinach, chard, cucumbers, tomatoes, peppers, herbs, and even flowers! The harvests are mainly useful for the winter crew, when airplanes aren't able to deliver fresh vegetables from New Zealand. The greenhouse can provide enough vegetables for the winter crew (up to 230 people) to have a salad every few days, plus some veggies for the cook to use in regular meals. During the summers, the population at McMurdo is too big for the greenhouse to supply completely, so it can only supplement the shipments of "freshies" flown down from New Zealand. But, more importantly, it provides a little piece of "summer" relaxation to the folks experiencing months of cold and gray, and many people visit just for the atmosphere.

Besides the great environment for relaxation and the ability to eat fresh vegetables, I've used the greenhouse in the past to test out our field equipment. The machines we use to measure gas flux (the LICOR) can measure not only soil respiration, but also photosynthesis (which is, essentially, the reverse process of respiration. So, instead of measuring a production of CO2, the machine measures a reduction in CO2.) Since the mosses we study in the dry valleys are so slow-growing, we need to know that the LICOR is working perfectly to measure such small amounts of photosynthesis before we take it to the field. The best place to test out the machinery is in a place where there's a lot of photosynthesis: a greenhouse!

However, this year, they decided not to open the greenhouse for the summer and rely completely on shipments of freshies, which is very unfortunate. I miss my regular visits with the plants, and we couldn't test our LICOR! I hope they change their mind for next summer.

Orca Sighting

As we come into late summer here in Antarctica, the sea ice covering the Ross Sea has melted back almost as far as McMurdo. That means that our helicopter rides back to McMurdo from the dry valleys start to scoot along the edge of open ocean, rather than traveling over solid ice. This makes for great sight-seeing, because there's so much life in the open ocean, even all the way down here! On the ice edge, we see penguins (both Emperor and Adelie), seals, and a lot of whales.

When we flew back from F6 on Saturday, we saw a lot of orcas. My camera doesn't do a great job from a distance, but in this video you can see a lot of them surfacing:


Orcas live just about everywhere in the world, but they tend to prefer polar waters, such as the Ross Sea of Antarctica where I am. They tend to stick to coastal areas, because that's where their food lives. While orcas are commonly called "killer whales", not all of them behave like killers. There are several types of orcas that we could see down here: Type A, B, and C. Type C are the smaller orcas that you see in the video. They have a duller white saddle (that white patch behind their dorsal fin) and eat fish. That's why they're along the ice edge here. The ice has just melted and broken away, so there's a lot of fish now without protection!

Type B are bigger and eat larger animals like seals (and penguins, if they were able to catch them, but penguins are usually too fast). In fact, when I met Sir David Attenborough last weekend, he narrated for us footage the BBC had recently shot of several orcas creating a wave to knock a seal off of a floating ice chunk and into the water so they could eat it!

Type A are the biggest and eat even larger animals, like minke whales. We also have a lot of minke whales in our waters here. In fact, we can see them from outside our lab window in the channel cut by the icebreaker! Minke whales are smaller, baleen whales. Baleen whales are a type of whale that have a plate for filtering small plankton from the water (rather than teeth for eating animals). So, minkes are related to humpback whales and Right whales, which are also baleen whales. It's easy to tell the difference between an orca and a minke because of the size, but also the shape of the dorsal fin. A minke's dorsal fin is small and curved. It looks kinda like the satellite radio antennas that you see on cars. (See what I mean using the photo on Wikipedia.)

We are hopefully going to the field tomorrow to visit Cape Crozier, the final penguin rookery I'd like to sample. Keep your fingers crossed that the weather cooperates!

3rd Annual Camp Hair Contest!

It is time for the Third Annual McMurdo Field Camp Hair Contest!

The water restrictions in the dry valleys means that we are not able to shower or wash our hair while we're out at field camps. That means that people's hair gets very dirty and oily, which of course leads to some very fabulous hair-do's! This is what we call having "camp hair." Having great camp hair is a matter of pride, and the person with the best camp hair is honored throughout McMurdo. So, once again, I'm going to leave it up to everyone reading my blog to decide who has the best camp hair for the 2009-10 field season. Review the photos below of our "camp hair" contestants, and send in your vote! Anyone reading this is welcome to vote, and can do so by sending an email with your choice to me.

Let's meet this year's contestants!

Michael:Stream Team member Mike has been living in the field at F6 since October, far from the comforts of civilization such as running water and a razor... and probably a mirror. Unfortunately for Mike, his "fierce grimace" has not aided the success of his attempted life as a pirate marauding the Ross Sea.

Julia:Fresh after her visit to the Wool Hat Salon, Julia is sporting her fashionable hat-hair look. Nine and a half hours of hiking, 4 soil pits, and an 85 pound backpack are all ingredients for this stylish look. See how happy she is to be able to finally take her hat off?


Jeff:Environmental engineering graduate student and temporary dweller of F6 Camp, Jeff engineers this gravity-defying look every day. Weekly camp showers at Lake Hoare can't keep his hair down! His sheer enthusiasm for field work is evident in this photo!

There they are: the 2009-10 season's Best Camp Hair contestants. May the voting begin! The champion Camp Hair will be declared in 5 days.

Back at F6

We finally made it back to one of the penguin rookeries that we needed to visit. After two days of trying to get to Cape Crozier but being stopped by bad weather, we decided to try for Cape Bird instead. Ross and I made it there on Wednesday. Finally, we were able to get some more of our sampling done! We did the same time of sampling at Cape Bird as we did at Cape Royds. It is interesting to do this at different rookeries because each of the three rookeries we want to visit have different sizes of penguin colonies living there. Cape Royds has several thousand breeding pairs of penguins, and Cape Bird has about 25,000. Cape Crozier has over 100,000! That means that "high activity" will be different at each of the rookeries, and we'll be able to learn more about the influence of different levels of penguin activity than we would at just one site.

There was one very curious penguin at one of our sampling spots. It wanted to inspect everything we were doing. At one point it even pecked at the shovel I was using! Here it is approaching Ross to see what he's doing with that sample bag:

I learned something very interesting about Adelie penguins while I was there! They have spiny tongues! Penguins eat krill, which are small shrimp-like animals that live in the ocean. The spines on the Adelie's tongue helps them hold onto and swallow the little krill. Here's a photo of an Adelie tongue that I found online:

[photo credit: www.penguinscience.com]

So that's what I did yesterday. Today I am back at F6 for the next few days to finish up some projects in the Fryxell Basin. Let's hope the weather stays as beautiful as it is today!

There's more than just penguins here!

When people think of animals that live in Antarctica, they almost always think of penguins, seals, and whales. And, while those animals do live down here, they don't live on most of the continent. They only live in or near the water, and not on the actual continent (except for penguin rookeries, like I've shown you). But, there are animals that do live on the actual continent! You just can't see them, because they're microscopic. Most of our studies focus on how these animals respond to changes in environmental conditions and influence biogeochemical cycling. So, it's important for me to tell you more about them! Here's some information about the main types of micro-organisms that live in Antarctic soils.

Nematodes

Also called roundworms, nematodes live EVERYWHERE in the world. You can find them in every biome in the world. They live in water, soil, ice, even in other animals! They are the most abundant animal in the world. In the dry valleys, we find more nematodes than any other animal. They are what our collaborators at Colorado State focus on studying. We have three main species that live here. The most numerous species, Scottnema lindsayae, is in the photo to the left.

Nematodes eat a lot of different things. Some, like the guy at the left, eat bacteria. Others eat fungi or algae, and some are even predators that eat other microscopic soil organisms. In the dry valleys, a predatory nematode is the top of the food chain!

Rotifers

https://en.wikipedia.org/wiki/Rotifer

Rotifers also live in a lot of different environments, including fresh water, saltwater, soils, and other watery environments. A rotifer eats by waving the hairs around its mouth (at the top, in this picture) to catch things floating in the water. The moving action around their mouth looks kind of like a wheel, which is how they got the name ROTifer (like rotate). The "foot" (at the bottom of the picture) is to anchor the rotifer when it doesn't want to move.

Tardigrades
Tardigrades are also called water bears, and looking at the picture I think you can see why! They even have claws at the end of their feet, which you can see in this very close-up microscrope picture that Uffe took of a tardigrade foot. The claws let them hold on to something as they float through water or the water-filled spaces in the soil. Tardigrades eat with a stylet that they use to pierce animal and plant cell walls.

Tardigrades are able to live in a lot of extreme environments, and are found everwhere from the Himalayas to the ocean floor to Antarctica. They can withstand the pressure of a vaccuum, radiation, dehydration, and both incredibly high and low temperatures. There are even experiments that test tardigrades' ability to live in open space! In the dry valleys, they especially like to live in the moss and algae patches, where food and water are readily available.

The soil environment in the dry valleys is a very hard place to be an animal. There's not a lot of water, not a lot to eat, and it is very cold! Most of these micro-organisms have a special ability to help survive in such a harsh environment. They can go into anhydrobiosis, which essentially means they can freeze-dry themselves. They can push out all of their water and curl up, so that they don't freeze and die. Their metabolism drops to almost a stand-still! They can stay in anhydrobiosis for a very long time, and immediately wake up if water becomes available.

In addition to invertebrates like these guys, we also study microbes: the bacteria and fungi. These are more abundant in the soils than the invertebrates and have a larger role in the cycles we study. We look at the bacteria and fungi through our lab work and measuring CO2 flux. But, they aren't as cute to look at in a blog posting!

Waiting for a Helo... AGAIN!

We've been trying for the past two days to get to Cape Crozier, one of the other penguin rookeries we want to sample. But, bad weather strikes again! We haven't been able to make it. So, we've been spending our time processing samples in the lab.

It's very busy in the lab when we're all working. A lot of different things are happening at once. In this video, Uffe is in the laminar flow hood (in the back) weighing soil samples to be extracted for invertebrates, which he puts on the sink for Diana to process. She uses tap water to rinse the soil through a sieve and capture the invertebrates in a very small-mesh sieve. Zach is on the other side of the lab centrifuging samples, and every now and then he pops into view to bring Uffe a new sample. Once Uffe has poured soil into a beaker for invertebrate extraction, he then pours part of the sample into a sieve for me. I sieve the sample to remove all of the rocks, then pour the soil into a bag for storage. We'll take that bag of soil back to Dartmouth to measure chemistry. The rocks go into the waste bucket, and I wipe the sieve for the next sample. Meanwhile, Julia is measuring soil samples into tin cans for soil moisture. She keeps going to the fridge to get a new sample, weigh out 20 g, record the weight, then bring it back to the fridge. Jenn is just off-camera measuring pH and EC on her soil samples.


Hopefully we'll be able to make it to a rookery tomorrow!

Dr. Becky Meets her Hero in Antarctica

We've had a very special guest in town at McMurdo for the past week or two. Sir David Attenborough is down filming for his new nature series called Frozen Planet. This is the man who has narrated so many great nature series for the BBC. I grew up with The Trials of Life. You might know him from Planet Earth. You might not recognize his name or his face, but you know his voice, especially if you're my age. I have been SO EXCITED that he's here, because he is one of the inspirations behind me becoming a biologist. My sister and I have watched The Trials of Life over and over again since we were kids. Sir David's films make the many amazing aspects of our natural world so accessible and exciting to kids (and adults!), and he's been a major inspiration for most biologists my age.

So, I can't even tell you how excited I was when I actually got to meet Sir David last night!! I was able to tell him how big of an influence he has been and about what kind of research I do here in the dry valleys. Here's me with my hero:I also asked Sir David what he thought was the most amazing thing he's seen in Antarctica. His answer: the Trans-Antarctic Mountains. That's the mountain range that runs through the continent dividing it into an East and West half. It's one of the longest mountain chains in the world! Mountain ranges like the Trans-Antarctics are created through a process called "uplift", where two plates are pushed together, and the force of them being pushed together causes the contact point between the two plates to rise up. The presence of the mountains is what prevents the ice sheet from flowing in the valleys, creating the dry valleys where I work. Sir David thinks they're amazing because not only are they beautiful and created through such an amazing feat of nature, but because of the huge challenge they've posed for humans for over a century. When the early explorers were seeking the South Pole, they started from the Ross Sea (where I am) and had to attempt to cross through the Trans-Antarctic Mountains. Crossing these mountains posed a huge danger and required a large amount of hard work under grueling conditions for the early explorers, and frequently groups were stopped by the presence of the mountains. It's just one way that nature is more powerful than man!

So, last night was a very special moment for me. When I was a kid watching the Trials of Life on video, I never would've thought that many years later I'd meet Sir David Attenborough all the way in Antarctica!

Penguins Aren't Just Cute: They Influence Soil!

Yesterday, all four of us went to Cape Royds where there is an Adelie penguin rookery.

Adelie (pronounced uh-dell-ee) penguins are one of two species of penguin that are found in this area. (The other species is the Emperor penguin.) Adelies are fairly small penguins. You could easily fit one in your school backpack. They are easy to identify by the white ring around their eye. Adelies mate and nest in rookeries like this one on the rocky capes of Ross Island, which is made out of volcanic basalt. Adelies make their nests on the ground by creating a hollowed-out bowl and carrying lots of small rocks into it. Right now, the Adelies still have some chicks that they're taking care of. You can see one huddled underneath its parent in a nest in this photo, just to the right of center. Adelies nest on land, but they spend the rest of their time out on the sea ice, because they eat krill in the ocean. So, the open ocean isn't very far from this rookery. I'm standing very close to the edge of the cliff to take this picture, and the ocean wraps all the way around the peninsula. You can see it on the horizon at the other end of the rookery. Because they eat from the ocean, their guano smells very fishy. It is a smelly place to be!

We are interested in the soil at penguin rookeries because penguin guano is very high in nitrogen and phosphorus. Nitrogen and phosphorus are two key elements that we focus on in the dry valleys with many of our experiments (like the stoichiometry experiment where we add the solutions containing N and P). The soils at penguin rookeries are naturally very high in N and P because of all the penguin poo, which makes it a nice comparison to have for our experiment. I am interested in knowing how soil organisms and nutrient cycling respond to such high levels of N and P in Antarctica, so penguin rookeries are the place to find out!

We sampled soils from four different types of locations at the Cape Royds rookery. We sampled from soils in a nesting area (the areas that are really orangey pink from all of the penguin guano), areas outside nesting grounds but still highly trafficked by penguins (the gray areas in the photo), areas with very low penguin activity (just the occasional passer-through), and areas not trafficked by penguins at all. We took soil samples from these different locations, and we'll measure their chemistry and microbial community. The soil here is really hard and compacted from all of the penguin foot traffic. In this video, you can see how hard Ross has to dig to get a soil sample. Jenn was helping take samples by opening bags for Ross, and Julia was in charge of labeling. Meanwhile, I was documenting every sample location with my camera and by drawing maps, so that we would know exactly where every sample came from.


In addition to taking soil samples to measure chemistry, I also measured CO2 flux to estimate the amount of respiration coming from the soil organisms. Because there's so much more nitrogen and phosphorus, the respiration rates were about ten times higher here than they are in the dry valleys!I also took a lot of extra soil from these areas so that I can set up a miniature stoichiometry experiment in the laboratory and do similar fertilizations as the ones we're doing in the field. So now our lab refrigerator is full of stinky penguin soils that will be shipped back to Dartmouth!
I hope to visit two other penguin rookeries that are on Ross Island: Cape Bird and Cape Crozier. You can see on this map where they are in respect to McMurdo and Cape Royds. (The dry valleys are on the mainland about 70 miles to the west.) Hopefully I will be able to tell you more about other penguin rookeries in the coming weeks!

Measuring Biotic Activity

Today, Julia and I went to the Lake Bonney basin to take some measurements on the stoichiometry plots. This is the experiment I posted about a couple days ago, where we add carbon, nitrogen, and phosphorus to the soil to see how it influences soil organisms and nutrient cycling. We do this experiment at two locations: Lake Fryxell basin (where I posted from before) and Lake Bonney basin (where we were today). We use these two sites because they naturally have very different nutrient conditions. Bonney has a lot more nitrogen, and Fryxell has a lot more phosphorus. That means that the two sites might respond differently to the nutrient additions, which would be very interesting!

One of the ways we measure the response of the biota is by measuring carbon dioxide flux. When most soil organisms respire, they produce carbon dioxide (abbreviated CO2). Humans do this when we breath, too. We breath in oxygen and breath out CO2. Soil organisms, from bacteria to nematodes, also respire to produce CO2. By measuring the amount of CO2 coming out of the soil, we are measuring how much the soil organisms are respiring. We hope to see an increase in respiration when we add nutrients (specifically, more respiration when we add C and P to Bonney and when we add C and N to Fryxell).

After adding the nutrient treatments to the plots like we did a few days ago, we go back and measure CO2 flux. We do this using a machine called an Infrared Gas Analyzer (abbreviated IRGA. It is made by a company called LI-COR, so we usually call the machine the LICOR). Here's Julia learning to use the LICOR: This is a fancy, expensive machine (about $25,000 for the whole set-up) that nests over the soil and sucks air from the space just above the soil. That air is sent through the tubing to the yellow box, which contains the IRGA. The IRGA measures how much CO2 is in the air space above the soil and how much the concentration of CO2 changes over one minute. If the soil organisms are respiring, we will see an increase in CO2 in that air space at a certain rate, called the "CO2 flux". We hope to see a bigger flux rate when we add nutrients.

We finally had a day of nice weather in the field, so we were not delayed for once! We are back in the lab now at McMurdo processing more of our soil samples from these stoichiometry plots. We head back to the field on Thursday, hopefully to visit a penguin rookery!

Snowfall in the Dry Valleys

I've spent the past five days in the dry valleys. As you've heard, we were weather-delayed getting out there. Then weather delayed my team from meeting me there. Then, my team got stuck there with me and couldn't get back to McMurdo. There was a lot of snow!

That snow doesn't stick around long. We don't have to wait for warm temperatures to melt the snow in order to see it disappear. In the dry valleys, the air is so dry that the snow will sublimate: turn directly from solid (snow) to gas (water vapor) and disappear from our view. On Thursday morning, there was a little over an inch of snow on the ground, but it all disappeared that day even though the air temperature never got above freezing.

These are all photos of roughly the same scene behind our hut at F6, looking north at the Kukri Hills. Here it is at 9:00 in the morning with an inch of snow, while it was still snowing a little bit. You can't even see the mountains because the clouds are so low:

And at noon:

And at 2:30 in the afternoon:

And at 6:00 pm:

And 7:30 pm:

And by midnight, it was gone:

Similarly, another group here has a camera set up in a different valley, called Wright Valley, and are taking time-lapse photos of one particular area. You can see snow come and go over the course of hours! Click here to see it on YouTube.

We think that most of the snow turns into water vapor, but some of it does melt. That extra moisture in the soil will be really important for the organisms living in the soil that are usually water-deprived. To find out how much moisture was getting added, we decided to take soil samples under the snow as it was ablating. Every few hours, we scraped away the snow and took soil samples from the surface (0-2 cm into the ground) and just below the surface (2-5 cm into the ground). We'll measure the soil moisture of those soil samples to see how much water melts into the ground from the snow and whether it ever trickles down to lower depths in the soil.

Now that we're finally all back in the lab at McMurdo (but barely, we almost got stuck at Marble Point, the helicopter fueling station, for the night!), I spent the day weighing out samples for soil moisture. Tomorrow, I will know how much the moisture was influenced by the snow, and how quickly it disappeared!

Tomorrow, I'm heading to the field with Julia, Zach, and Bishwo to sample and treat the stoichiometry plots that are at Lake Bonney. It is supposed to be a day trip, though, so there shouldn't be any getting stuck.

Stoichiometry Sampling... a Little Late!

We finally got a small enough window in the bad weather for me to get out to the field yesterday. Now I'm back at Lake Fryxell. The work that needs to be done right now is the annual treatment of our Stoichiometry Plots. These are for a long-term experiment that has been going on for several years. We hypothesize that, if the climate warms, there will be more liquid water. With that liquid water comes more nutrients in the soil. We want to know how the soil organisms respond to that nutrient and water pulses to influence nutrient cycling so that we can predict how climate change might influence the soils. So, we are adding water and nutrients to simulate this type of change. Every year we add more nutrients and every two years we take soil samples to measure the response.

To add the treatments to the plots, we have to bring a LOT of water to the field: 775 pounds of water! That means we need a lot of team members to help us carry the carboys of water solutions. Because we've had so much bad weather, our team has had to split up a lot, so only 3 of us were being sent to Fryxell to do all of the work sampling and treating the plots. It is myself, Bishwo from Brigham Young, and Zach from Colorado State. Unfortunately, the weather went sour just about as soon as I landed, so Bishwo and Zach couldn't make it to join me! I did all of the soil sampling by myself, so that the samples could be sent back to the lab for processing. They had to wait overnight, because no helicopter could come pick them up. Luckily, there was another window in the bad weather this morning, and Zach and Bishwo were able to join me for our work, and that same helicopter took our samples home to be processed while we added the treatments.

We needed to add water solutions containing carbon, nitrogen, phosphorus, carbon+nitrogen, carbon+phosphorus, or just water (as a control) to eight sets of replicate plots at Fryxell. We carry the solutions to the field in 35 ten-liter carboys, and then transfer 5.6 L at a time to pour jugs with sprinkle caps to be applied to the plots. It takes a lot of organization and communication to apply the treatments to the plots without messing up. We can't add the wrong solution to the wrong pour jug, or pour the wrong solution to the wrong plot. If we mess up and add a nutrient to a plot that's not supposed to receive nutrients, we ruin years worth of data and the future of a long-term experiment! So, it was a challenge to do the work with so few people in a short amount of time, but without rushing and messing up. We worked out a system where I filled the pour jugs for Zach and Bishwo, who were each assigned to a particular nutrient treatment. We check and double-check that I'm filling their jug with the correct solution. Then I direct them to the correct plot to apply their treatment using a map. We have to check and double-check that they're at the correct plot before applying the treatment to make absolutely sure that the wrong solution doesn't get used. They use a fiberglass cone to contain the water to the necessary area while they pour in a spiral pattern. Otherwise, the wind would blow it away from the plot! Once they've applied the nutrient solution, they come back to be refilled. We're constantly talking to each other and looking where we're going. Here's a short view of how it worked:



Unfortunately, the weather went bad again, and now Zach and Bishwo are stuck at F6 with me! It's snowing outside as I type. But, at least the work is done and the samples are at home. The rest of the Dartmouth crew is busy in the lab processing the samples, because we're planning to do the second site for the Stoichiometry Experiment on Friday!

McMurdo Weather

After 4 days at station working in the lab, we were supposed to be going back to the field today. But we have yet another bad-weather day that won't allow us to fly! So this is a good time to blog about weather in McMurdo.

We are in a polar desert. That means that there is very little precipitation, just like deserts in the U.S. But this is a polar desert, which means it is very cold, not hot like deserts in the U.S. We do get storms here, but they are mostly made up of wind and clouds and involve only a little bit of precipitation. The little bit of precipitation we get comes as snow, and most of it returns to the air before it melts into liquid water on the ground (that's called sublimation). So, it occasionally snows in the dry valleys, but when it does, it usually only looks like this for a few hours before it disappears.
Right now, we have a snow system over us. In this radar image, you can see where I am right now at McMurdo Station (at the "You Are Here" arrow). There's a big bunch of clouds right over us and the dry valleys where we're trying to go! There's not a whole lot of snow coming down. There's just a dusting on the ground, but it really restricts visibility, especially over the ice. Here is a picture looking out of our lab window across McMurdo Sound on a normal, sunny day. You can see all the way across the ice to the Trans-Antarctic Mountains and the dry valleys where we do our research.

And here's a view out of our window today.

You can't see very far! And since the ice is white and the view ahead is white, helicopter pilots can't see the difference between the ground and the sky, which makes it unsafe to fly. We've had more snow than usual this summer. I've heard from people here earlier than me this spring that at one point there were eight inches of snow on the ground in the dry valleys! That means there's more moisture on the ground from the little bit of the snow that melts, and the soils are wetter than normal. Since the soils are so water-limited, that can change a lot!

Though it's too dangerous to fly, and it's cold and there are snow flurries, it is still not truly bad weather. This area can get far worse storms that include really strong winds and white-out conditions. The strongest and most dangerous type of weather is called a "herbie". Herbies are very strong windstorms coming from the south that bring along a lot of blown snow and very cold wind chills. They can come without much warning, and people will suddenly find themselves with no visibility and dangerously low temperatures. Luckily, they are not very common, and I haven't been here for a herbie yet. I have been here for a different type of windstorm called a katabatic wind. This occurs when cold air from the south gets pushed up higher in elevation to go over a mountain (like the Trans-Antarctic Mountains). Normally, cold air sits lower on the ground and warm air rises higher, because warm air is less dense. When cold air gets forced higher due to a mountain, it'll eventually reach the top of the mountain and then rush back down to the ground on the other side. It rushes down because it gets pushed down by the warm air waiting for it on the other side and squeezed into a smaller space of a valley. This can cause huge, fast gusts of wind that rush down the valleys where we work. We've seen tents be blown away before, and at times entire buildings have been blown apart. These happen most in the winter when there is a lot of cold air coming from the south, but there are occasionally katabatics in the summers, too.

To manage safety during these different types of weather, we use a rating system that restricts activity for people on base. Condition 3 means the weather is fine, and people can move about normally. Condition 2 means stronger winds and colder temperatures, and you have to receive permission to leave the base. Condition 1 means the weather has gotten really bad, and you're not allowed to leave the building or vehicle that you're currently in. So if it turns to Condition 1, you'd better hope you're in the Galley so you can have something to eat while you wait! We can find out what Condition we're in using these electronic notices posted around station, as well as colored lights that are mounted on the outside of the buildings.Even though the weather right now is bad and it's snowing, it's still Condition 3. We can move around base, we just can't fly. Our weather service on base is predicting snow for the next several days, so it's not looking good to get back into the field!

Our Group is Complete!

Our other two group members, Ross and Julia, arrived yesterday in Antarctica. Our group is now complete! We've been very busy working in the lab, but we plan to head back to the field on Monday. That's all the news for now!