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!