The great moss hunt

This is my second day of field work in the dry valleys. Today I was sampling along stream edges for moss. I've been sampling moss for a few years in the dry valleys, and I'm trying to sample from new areas this year that I haven't sampled in the past.

Moss is the only true plant in the dry valleys, though it hardly fits the definition of "plant" that most of us think of. Moss are bryophytes, which are a type of non-vascular plant. In the dry valleys, where temperature, sunlight, and dryness are very harsh to deal with, they grow very slowly. We find them mostly in small patches near sources of water, like streams and snowpatches. Here's a photo of some moss I was sampling at Crescent Stream. Can you see the moss? It's reddish-brown and looks kind of fluffy.During the winter there's no sunlight for photosynthesis, but during the summer the sun can be so intense that it can actually damage plants. (Largely due to the intense UV radiation that I mentioned a couple days ago.) Most of the time you do not find moss that is lush and green, because it's usually too cold, too dry, or there's too much sun damage. The moss I find tends to be brown, because it is "moribund". That means it's not dead, but also not very healthy. The moss is less active in that state, but parts of it can be. I can find green moss in spots where it's protected from the intense sun, though. Here's a little patch of green moss that I uncovered when I moved a rock out of the way at Crescent Stream.

Just like all other plants, moss need water and nutrients to grow. I want to know where the moss is getting its nutrients from. I'm interested in the nutrients in moss because, when mosses die, they decompose in the soil. The carbon and nutrients released from mosses when they decompose are probably a very important part of the soil food web that our group studies. So, when I sample the moss, I also sample the soil, stream water, and ground water, which are the possible sources of nutrients for the moss. You can see some of my tools in the photo above. I scoop the moss into a bag with a spoon, then the soil beneath with a little plastic shovel. I take stream water right out of the stream into a bottle. The trickier part is getting the ground water. To do that, I use a miniature well called a piezometer. Essentially, I insert a tube into the ground until it hits the ground water, then I use a vacuum pump to pull the water up into my flask. Here's a video showing you how it works (as well as some nice scenery along Crescent Stream!).



Since the dry valleys are a desert, moss need to grown near a source of water. The easiest place to find them is right next to a stream. So, to do this sampling, I tagged along with the Stream Team as they went about their daily chores at some of the streams. They have to measure the amount of water flowing in each of the streams and take stream water samples for chemistry. Since I can't travel by myself, I was able to go to the streams they scheduled to visit today to do my moss sampling at the same time. This is what they were doing while I was sampling moss:I was able to sample moss from four streams since I've been here, all along the south side of Lake Fryxell. I hiked from one end of the lake to the other, stopping at each un-sampled stream area that I came across. I'm tired!

Into the Dry Valleys

Today I left McMurdo Station and headed to the dry valleys to being my field work.

Every time I go between McMurdo and my field sites in the dry valleys, I fly on a helicopter. First, all of my camping equipment, my hiking gear, and the tools I need to do my research had to be loaded onto the helicopter. We leave things like that to the professionals. Here are the heli-techs loading up my gear this morning:


Meanwhile, we stand back and wait for the signal to get on the helicopter. This morning I flew with my new friend Derrick, a scientist who will be using radar to map melting water from snow and glaciers in the dry valleys. This was his first time going to the dry valleys. See how excited he is?

Then, we flew across McMurdo Sound to the dry valleys on the mainland of the continent. Of course, the water is covered in ice, so we're not flying over open water. It takes about 30 minutes to fly across and reach the field camp.

And then, we reached Taylor Valley, where I spend most of my time in the field.

So now I am back at my favorite field camp called "F6". It's on Lake Fryxell in Taylor Valley. I have an absolutely beautiful commute to work!

Ozone over Antarctica

There are a lot of reasons that working in Antarctica can be dangerous. It's cold, windy, and very isolated. One danger that is not as obvious is Ultra-Violet radiation (called "UV" radiation).

UV radiation comes from the sun. The sun naturally puts out a lot of different types of radiation. Some of that radiation we can see as visible light and colors. Some of the radiation we can't see, like UV. Radiation from the sun also carries energy. Some of this energy is very useful. It allows us to see, plants use it to photosynthesize, and much more! But some types of UV radiation are packed with so much energy that it can be dangerous if we are exposed to too much.


Luckily for us on Earth, there is a layer of ozone surrounding us in the atmosphere. Ozone is a molecule made up of three oxygen atoms (written O₃), and it can bounce back harmful UV radiation and prevent most of it from making it to the Earth's surface. That is why the ozone layer is so important. It helps protect the Earth (and everyone on it) from harmful UV radiation. You can see in the diagram that there's a lot of "rays" of radiation coming from the sun, and some of those are stopped at the ozone layer. Only the helpful parts can make it through.

I'm sure you've heard about the hole in the ozone layer. But how did it get there, and what does it mean?

Humans produce some chemicals that can break apart that O₃ molecule. These are chemicals that are made for many useful day-to-day purposes, and we didn't know they broke apart ozone when we started using them. Some of the major chemicals involved are called CFC's (which stands for chlorofluorocarbons... but CFC is a lot easier to say!). CFC's were used in refrigerators and as a propellant in aerosol cans. We liked to use these chemicals because they are not toxic and very stable (meaning they keep their chemical structure for a long time). That made them easy to store for long periods of time and safe for people to use. They are also very light, which means they can float up through the air once they are released from the aerosol can or refrigerator. At first, we didn't know that they were harmful to ozone. But, as more and more people used CFC's, more and more were allowed to float freely around in the atmosphere, eventually rising high up enough to reach the ozone layer.

Here's what happens when a compound like a CFC is in the ozone layer. In the ozone layer, the CFC is exposed to the UV radiation that it had been previously protected from when it was beneath the ozone layer. The UV radiation, because it is packed with so much energy, can break off pieces of the CFC compound. A single chlorine atom breaks off of the CFC in this process. It is actually the chlorine that breaks apart the O₃ ozone molecule. O₃ gets broken apart and is no longer useful for absorbing UV radiation.
If you want to know more about how the reaction occurs in the atmosphere, click this image to make it bigger and read about it:
So why is there one hole in the ozone layer, instead of over the whole planet? Air in our atmosphere moves around. It circulates. (Just think of wind. The same thing happens higher up in the atmosphere.) What ends up happening is that a lot of the CFC's gather together at one spot in the atmosphere that happens to be over Antarctica. The CFC's get trapped down here because of the winds that circle the continent. Because Antarctica is dark for 6 months of the year, the CFC's can build up. As soon as spring arrives and sunlight reappears, the CFC's can be broken, the chlorines released, and the ozone is eaten up!

Here's a map of the bottom half of the globe. The blue/purple areas are where the ozone is almost gone during the summer. The green areas still have an ozone layer. You can see that the ozone hole is very big... bigger than Antarctica!

The ozone hole is not something you can see with our naked eye. The sky doesn't look different. But we see evidence that it is here. During the summer when the hole is present over Antarctica, we receive almost the full blast of UV radiation during the summer when the hole is present. People can easily get sunburn. Also, anything brightly colored fades pretty quickly here. A good example are the orange bags we are issued. In this photo from the airplane runway, you can see quite a variety of shades of orange bags. When they're new, the bags are bright orange and have black straps. Through time, the bags become lighter and lighter, and the straps turn gray. All of the bags in this photo at one point looked like the bright orange one under Liz's head (she's the girl lying down on the left).


Of course, being under the ozone hole is bad for life in Antarctica. As people, we can take extra precautions. We wear a LOT of very strong sunblock. However, wildlife cannot. Scientists working here have noted harmful effects of the increased UV on marine life and other animals.

It's also not just bad for Antarctica. The ozone hole allows more UV radiation to enter over Antarctica, but that energy doesn't just stay around Antarctica. Like I already said, the air in our atmosphere moves around the planet. So extra incoming radiation over Antarctica means more radiation energy for other places on the planet, too. That extra energy can cause all sorts of changes, like increases in temperature, changes in wind patterns, and shifting ocean currents.

So the ozone hole is not just a problem for Antarctica! It is something that we all became concerned about, and we took action. An agreement was signed by many countries requiring them to make laws to reduce the use of ozone-destroying chemicals like CFC's. And it's working! These chemicals are decreasing in the atmosphere and the ozone hole is slowly repairing itself. But, it takes a lot of time to fix a problem that was caused in a very short period of time. Also, there are more than just CFC's that damage ozone. For example, N₂O (nitrous oxide) is released from agricultural fields that are over-fertilized, and when N₂O reaches the ozone, it also breaks apart into compounds that can break apart O₃. So, getting rid of CFC's is a great first step, but we also have to start thinking about ways to reduce some of the other chemicals we release that can harm the ozone.

[Credits: Earth and ozone layer image from http://www.hermes-press.com; CFC and O3 image from http://www.tutornext.com; map of the hole from http://www.coolantarctica.com]

About McMurdo Station

I've spent the past couple of days at McMurdo Station setting up our lab and prepping for the field. McMurdo is the largest of the three U.S. research stations in Antarctica. (We also have Palmer Station on the peninsula and one at the South Pole. Also, there are two icebreakers that cruise the Southern Ocean for marine research.)In addition to the three U.S. bases, the U.K. bases are also labeled on this map. There are, of course, many bases owned by other countries across the continent that are not labeled on this map.

McMurdo Station sits on Ross Island in the Ross Sea, at the bottom-center of the above map. (The area is named after James Ross, the earliest explorer to reach land in this area of Antarctica in the mid 1800's.) If we zoom in on the McMurdo area, you can see that, while I am here at McMurdo Station (the red dot), I'm not actually on the mainland of the Antarctic continent. We are, however, on the edge of the permanent ice shelf, an area of the Ross Sea that is frozen on top year-round, so it is frequently considered to be part of the continent. That's why it's shaded a different color in the first map. Below Ross Island (to the north), the Ross Sea is also frequently ice-covered, but it melts back, sometimes as far as McMurdo Station, during the summer months. In the map above, you can see how some of that ice is breaking apart around the island. It is called "sea ice", not the "ice shelf", because it is a different piece of ice than the permanent stuff that makes up the ice shelf.

Also on Ross Island is Mount Erebus: the southern-most active volcano in the world. (The volcano is named after James Ross's ship, The Erebus.) In the second map, Erebus is the black-tipped cone on the right side of the island. Mt. Erebus is always looming in the background here at McMurdo. This is what it looks like from the ground while standing on the ice shelf near McMurdo Station:
In this photo, Erebus is pretty quiet. Some days we see it puffing smoke quite a bit.

Here's an aerial view of McMurdo Station:
McMurdo and the other U.S. research stations on Antarctica are funded and managed by the National Science Foundation. Research here has been going steady since 1956. Contractors and the U.S. military provide the support to operate the bases and make the scientific research possible. Some of the research is to understand the Antarctic region and ecosystems, as well as the region's response to changes in climate. This includes studying glaciers, geology, soils, and oceans. People study the chemistry, physics, and biology of all of those components. Also, Antarctica is the home to a lot of atmospheric and space research, because the atmosphere is thinner here than other parts of the planet. That means that there are a lot of scientists at McMurdo studying a wide variety of topics, plus enlisted military and contracted support staff (usually adventure-seekers). During the summer season (right now), the total number on base is over 1,000 diverse people. You never know what kind of conversation you'll have when you sit down for dinner!

I have two more days to get myself prepared for my field work. On Monday, I should be heading to the Dry Valleys, which are across the McMurdo Sound on the mainland of the continent. Where I'll be heading is labeled with the orange dot on the second map.

Arrival in McMurdo

I have arrived at McMurdo Station, Antarctica!

Today, I woke up early in Christchurch, packed my bags and headed to the airport. There, I boarded a U.S. Air Force C-17 and flew from New Zealand to Antarctica. It's about a 5-hour flight. There was a big crowd on the plane this year: about 60 people. Only half of us were American. We flew down with a lot of Italian and French scientists who headed to their own bases after they arrived at McMurdo.


The runway that we landed on is built on the seasonal sea ice, so it is called the "ice runway". It's rebuilt each year and used until early or mid-December when the ice starts to break up. In my previous years, I've always arrived after the ice runway has been closed, and have landed instead at Pegasus Airfield, located further back on the permanent ice shelf. So, it was a different landing for me this year! The ice runway is much closer to McMurdo Station, so the journey from the plane to the station was much shorter than I'm used to. You can even see the ice runway clearly from our lab window:
Tonight I'll be getting settled into my room and lab. Tomorrow, I begin the preparations for getting out into the field to get my work done. It'll be good to revisit all of the people that help me do that!

Gearing Up

Today I went to the U.S. Antarctic Program office in Christchurch to be outfitted for gear I will need in Antarctica. I wear a lot of my own personal clothes and gear, but I also use a lot of special issued gear. The board in the picture shows the variety of clothes they give us: everything from long underwear and socks to coats and hats. We have to try on all of the clothes to make sure they fit.


Because Antarctica is very cold, we have three layers of clothes for warmth. We wear polypro long underwear pants and shirts , and then two layers of fleece. On top of the warm clothes, we have a wind-proof layer of overall pants. Here you can see me wearing my long underwear shirt and pants, topped by my wind pants.The boots I'm wearing are called "bunny boots". They are very insulated and water-proof to make sure our feet stay warm and dry. The insulation makes these boots very bulky and heavy, so walking in them can become hard!

On top of everything, we wear a down parka with a fur-lined hood. The giant red parkas is nicknamed "Big Red". There is a also a light-weight, red wind-breaker, which is called "Little Red". Big Red is very warm, but it is very large and bulky. Unless it's very cold, I prefer to wear Little Red for my field work.


Once we have picked out all of our clothes, we pack everything into the two orange duffel bags. Those two bags contain all of the gear and clothing we will use for the next two months!

Our flight to Antarctica is scheduled for very early tomorrow morning. We have to leave the hotel by 6 A.M. Let's hope the weather over McMurdo stays good so that we can get out of here on time!

In Christchurch, New Zealand

I have landed safely in Christchurch, New Zealand. This marks the end of the first portion of the journey. I will spend a couple days here getting prepared (and enjoying some summer weather) before I head down to McMurdo.

Check out this photo I took as we were flying over New Zealand near Christchurch. It's a beautiful country!


The river that you see running through the middle is called a "braided river". It's a series of smaller channels of water that twist together and are separated by sand bars. This type of river is found in areas where the ground is easily eroded to create a lot of sediment (which creates the sand bars) and where there are rapid changes in the amount of water flowing in the river. The mountains in the background are geologically young, and easily erode to create that sediment.

Braided rivers are common here in New Zealand, but also in Antarctica. Here's a photo I took a few years ago when I was flying over the Onyx River in the McMurdo Dry Valleys of Antarctica, where you see the same braided pattern:


(You'll notice one thing unique about Antarctica: there are no trees, roads, or houses to give you a sense of size, like you have in the New Zealand photo. This photo was taken from a helicopter pretty high up, but you wouldn't know that if I didn't tell you!)