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Snow Photochemistry Experiment at Summit,
Greenland, March-May
2004
Question and
Answer page
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The photochemistry team at Summit in Summer
2003
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What would you like
to ask the Summit science team??
Email your questions
to: Nicola (nblake@uci.edu)
Summit Middle School, Boulder Colorado
Questions from Haydee Phelps'
7th Grade Earth Science Classes:
Question:
Is there any wildlife? If so, what kind.
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Answer:
The only wildlife that makes it to Summit are birds. And
they do not survive very long up here (maybe a week or so) because of they
have flown a long way to get here, it is cold, and they have nothing to
eat (no bugs, no seeds, no worms, etc.) Yesterday we saw our first
bird of the spring, we think is was a Buff Breasted Pipet, but we are hoping
to get a photo of him to make a positive identification. About 5 different
people saw the pipet around camp yesterday.
Last summer when we are up here we saw 10 or more birds, and a bunch
of different kinds, I don't know too much about birds, but one of the ones
we saw was a large seagull of some kind. Last summer we left some
food out for the birds but we never saw them eat any of it. Several
years ago, the camp staff caught a bird and kept him in a box for a few
days until the next plane came and gave him a free ride to the coast.
Whenever a plane is coming up soon we think about catching a bird and bringing
back to the coast with us. The next scheduled plane is coming in a couple
of weeks. - Barry
Lefer, National Center for Atmospheric
Research - writing from Summit
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Barry forwarded me some questions from
the students, and I would like to answer one of them, since my background
is biology (think I am the only biologist amidst a swarm of physical science
folks!).
Answer: Basically,
there is no wildlife at Summit Camp. Since there is essentially nothing
but snow and ice for an area roughly three times the size the state of Texas,
there is nothing for wildlife to eat for a long, long distance. However,
small flocks of birds at Summit Camp are not uncommon in the spring and fall.
Most likely, they get blown off course by a large storm during migration and
end up flying over the ice cap by accident. They can see Summit Camp
from many miles away against the plain white background, so they often investigate
it, probably hoping to find food, shelter, and rest in the middle of a vast
Arctic desert of sorts. Unfortunately, most of the birds die shortly after
reaching Summit Camp because, again, there is no food for them to eat and
they quickly succumb to the cold temperatures.
Actually, we observed our first bird here at Summit Camp two days ago.
I did not get a good look at it, but from the descriptions that others gave
me, I suspect it was probably a Buff-bellied Pipit (a small, sparrow-sized
song bird).
I have heard that very rarely, polar bears have been known to cross the
Greenland Ice Sheet, though I have not seen actual documentation of this.
It would not be surprising, however, as that species can roam for many,
many miles and during certain parts of the year, can fast for long periods
of time. Hence, they would be suited to make and survive a trip across
the Ice Sheet. However, that would be very uncommon and the chances
of one showing up at Summit Camp are probably lower than one's chance of
getting hit by lighting.
Now, that does not mean there are not any animals in Greenland... quite
the opposite! Areas along the coast where there is land between the
ice sheet and ocean often support high densities of animals, including caribou,
musk ox, arctic foxes, arctic hares, rock ptarmigan, numerous geese and ducks,
many small song birds, and a variety of other birds. The oceans surrounding
Greenland also support many species of animals, including numerous kinds
of fish, many seals, various sea birds and gulls, and a number of whale species.
So, though the Ice Sheet itself supports very little wildlife, the areas
surrounding the Sheet have many animals inhabiting them.
Hope this answers your question and all the best!
Cheers, Travis Booms, Summit Science Technician
- writing from Summit.
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Answer:
As Barry, and probably others, mentioned, the most frequent animal
visitors to Summit are birds. It is fun, but also sad, to see these
guys. They remind us that there is more in the world than endless snow,
but they are definitely lost and almost always doomed when the winds blow
them all the way up to here.
Arctic foxes have also made it here a few times. I saw one that
was in camp for almost 2 weeks one summer in the early '90s. In that
case we were pretty certain the fox had stowed away on a pallet in Kanger
and then got a free ride to Summit on one of the LC-130s. Our camp
manager was trying to chase the fox away, while the cook took pity on it
and was leaving food out! In the winter of 2000/2001 the people here
saw a lot of fox tracks for a little while, but I do not think they ever
saw the animal.
Like the birds, seeing foxes is a mixed blessing but for a different reason.
The foxes often follow polar bears around, hoping to scavenge a meal from
the leftovers when the bear kills a seal or walrus. Polar bears very
rarely venture up onto the ice sheet (because there is nothing for them to
eat) so it would be very unusual to see one at Summit. However, if
we ever did see a polar bear up here we could be sure of one thing, the bear
would be very hungry!!
.Jack Dibb, University of New Hampshire (UNH)
- writing from Summit.
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Question: Have
you gotten to play snow golf yet?
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Answer: No
snow golf yet, for two reasons, it is still too cold, and we have been busy
collecting our samples and analyzing the data. Last summer we got
to play snow golf on the 4th of July and after we finished our experiments
(and finished packing everything up) and were waiting for the plane to come.
Hoping to play again this year the last day or so we are up here.-
Barry Lefer, National Center for Atmospheric
Research - writing from Summit
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Answer:
Snow golf is fun only went we have the mobility to somewhat swing
a club and for the time being, it's been soo cold outside that we need to
wear several coats, gloves, facemasks, hence, our mobility is significantly
restricted. The temperature should warm up throughout the month so
that hopefully we'll be able to do more outside besides: check on instruments,
shovel snow away from doorways, and very quickly use the pee-pole.- Eddie Galbavy, University of California
at Davis - writing from Summit.
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Question:
What do you do to protect the equipment when the winds blow so strong
(in ref. to your 25 knot plus days)? Has anything been damaged?
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Answer:
The strong winds can cause problems with the equipment,
and with the strong winds comes blowing snow, which is even a bigger problem.
For protection from the strong winds we bolt the equipment to the tower or
the sampling bridge, or tie our lines and probes to bamboo poles that are
stuck deep into the snow. The blowing snow results in the snow drifts
that eventually bury everything on top of the snow. We have had to
dig our our instruments and our laboratory several times this spring.
We now have to go down 5 or 6 tall steps to get into our lab (last summer
this lab was on top of the snow), we also have to dig out our tents (and
the outhouse) each time the winds blow over 20 kts.- Barry Lefer, National Center for Atmospheric
Research - writing from Summit
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Question: Did
you like being the Mouse? What kind of music did you pick out for the day?
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Answer:
Being the Mouse is a lot of work. When you are the
Mouse you have to clean all the dishes, and cooking pots, vacuum the carpet,
mop the kitchen, clean the bathroom, take out the trash, and help the cook
with cooking (if she needs help). The good side of being the house
Mouse is that it is a good chance to do your laundry, take a shower, and
you get to pick the Music on stereo all day. I like a lot of different music,
some of the artists/bands that I picked for the day include: Dido,
Coldplay, Sting, Tom Petty, Johnny Cash, Natalie Merchant, REM, Sheryl Crow,
Indigo Girls, Jewel, Radiohead, Dave Matthews, etc. Music is big deal
up here since we can not see any TV shows. We do have a TV and a DVD/VCR
player, so we can watch some movies, but seems that we don't have time for
that, usually finish working around 11PM each night. So just go to bed.
The nice thing about music is that you can work on data while listening to
it. Everyone takes a turn a being the Mouse, and since we 20 people
up here now, you only have to do it once every 20 days. Being the mouse
is a nice change of pace, but I am glad that I do not have to do it more
often. Barry Lefer,
National Center
for Atmospheric Research - writing from Summit
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Answer:
Mouse duty ain't too bad when the snow-chemistry experiments are
going well because it's a nice rewarding break from our average diurnal schedules.
Often it's the only time to do some laundry and stay relatively warm in the
Big House. Contrary to what you might think, we don't have complete
control over the Big House tunes because our camp cook, Sarah, has supreme
squatting rights over that domain and the music which fills the air within.
While mousing, she has steered us to light folk such as Natalie Merchant
and Nora Jones. In our satellite camp the boom box is constantly rocking
but tunes tend to be not too hard, and not too controversial. So we've
had to stay away from Rap and Heavy Metal, and remain content with artist
such as Jonny Cash, Dave Matthews Band, and the infamous Mr. Jon Bon Jovi.
- Eddie Galbavy,
University of
California at Davis - writing from Summit.
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Question:
Is your cloud imaging equipment working?
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Answer:
Cloud camera is working great. Should be up on the
web soon. I'll send you an email when that happens. See photo
(right) of me taken while I was cleaning the cloud cam. I will let
you know where you can access a movie of one day of clouds. Barry Lefer, National Center for Atmospheric
Research - writing from Summit
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Question: How
do you move all that equipment to a new snow patch? Does it take a long
time?
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Answer:
We have most of the equipment mounted on Skis. My snow profiler is on skis, as is
the Snow Sampling Bridge, and the Bally Mobile Laboratory. I can pull
the snow profiler through the snow by myself, but it is easier with two
people. The snow sampling bridge takes 6 or more people to push it. For
photos see HERE.
Right now the snow is so cold that things do not slide on it very well.
Extra cold snow is more like sand than the snow we are used to in Colorado.
The Bally Mobile Lab is a couple thousand pounds of equipment in (and it
weights about 1000lbs. empty) is a lot harder to move. We have
an electric winch mounted to the front of the Lab and what we do is go bury an anchor in the snow about 50 feet away
and us that to pull the building along. Unfortunately, it seems that
the skis on the Mobile Lab are not wide enough for all the weight we have
in the building, so as we are pulling the Lab through the snow it is sinking
deeper and deeper into the snow. Last year we figured out that we
could use a really large metal plates (approximately 15 ft x 15 ft (and
3 inches thick)) to build a road to move the mobile lab. The metal
plates we have are the cargo pallets used by the C-130 aircraft used to
fly us and our equipment here. You can strap a lot of boxes to the metal
aircraft pallets and slide them in/out the rear cargo door. Luckily
there were a couple of extra aircraft pallets around and we have one underneath the Bally Lab and one right in
front of ski right now, so we haul the Lab onto the second pallet (and
off the first) and then go and put the first one in front of the skis and
repeat. The metal plate weigh a lot and takes at least 4 people to
pick them up and move them. The first day it took us a whole day to
move everything and get it set back up. Now that we have done it a
bunch of times, we can do it in 4-5 hours. But it is still a lot of
work. Especially if the Sampling Bridge and Bally Lab and been drifted
in by snow, then we have to dig everything out first, and that takes a long
time. Barry Lefer,
National
Center for Atmospheric Research - writing from Summit
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Answer:
Moving to a new location for sampling is a hard process. It involves
not only moving the equipment but also moving the Bally building which houses
the UCI, Georgia Tech, and Arizona experiments. Unfortunately, the only way
we have to move it is by a whole lot of pushing. It takes at least 4 hours
and when we are done everyone needs to set-up their equipment for the next
day's sampling. - Andreas Beyersdorf,
University
of California, Irvine- writing from Summit.
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Answer:
Everything we use and eat up here comes from a pallet that has been
brought up on a C-130-hercules-sized-airplane. Hence, it's packaged
pretty well and designed to be moved around pretty easily. During the
first couple days here, we use snowmobiles/snow-machines/Ski-doos (whatever
you want to call them), to move most official equipment down to our satellite
tent-structure/camp, from where most of us will work for the time we're here.
Close to our satellite tent-structure, there is a small building with skis
on its bottom, which houses more instruments right by the snowpack we're
currently testing. You might have seen pictures of this building (its
call the "Bally" building) on websites but you haven't experienced the struggle
we go through (about once a week) to move this building with wench and man-power
to new snow patches (often 10- 100 feet away). I guess moving equipment
is the means by which we get exercise every once in awhile. - Eddie Galbavy, University of California
at Davis - writing from Summit.
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Question: Are
you lonely or bored yet?
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Answer:
Not bored or lonely. The people that I am stuck up
here with are great. They are a lot of fun and we often make jokes
when things are not going well. I do miss my wife and my cat, but I
get to talk on the phone to my wife once a week and I email back home pretty
much every day. Instead of being lonely or bored, I am mostly tired.
Your body burns a lot of calories keeping warm, and walking over a half mile
(in the high altitude) from the Big House to the Sat Camp (were all the
instruments/experiments are) makes you quickly out of breath. That
and staying up late (or not sleeping well) make you tired. Barry Lefer, National Center for Atmospheric
Research - writing from Summit
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Answer:
And why might you think we'd get bored up here? With plenty
of interesting collaborators, great cuisine and a non-stop internet connection,
I'm almost considering sabotaging our departure plans so that there'd be
more time - just kidding. But you'll never know how nice it can be sometimes
to take a break from modern civilization. Eventually, we'll have to
head back to automobiles, television, overbearing advisement and consumerism;
but boredom is far from setting in. - Eddie Galbavy, University of California
at Davis - writing from Summit.
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Question: Did we beat
the other classes to asking you questions?
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Answer: The
New Hampshire and Arizona classes beat you to the questions, but we still
have not heard from classes in Georgia, California and Wisconsin, so 3rd
place is not bad. Some of your questions were similar to theirs, but
I was surprised how many new questions you guys came up with. Good job. Barry Lefer, National Center for Atmospheric
Research - writing from Summit
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Answer: Nope sorry,
but if it would make you feel better, you guys are the second class who I
have seen a set of questions from.- Eddie
Galbavy, University of California
at Davis - writing from Summit.
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Question: What kinds
of gasses are in the air pockets in the snow? What about in the air bubbles
in the ice? Is is from pollution or are they the natural gasses?
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Answer: There
are actually hundreds of gases in the snow, but aside from O2
and N2 they are all in very small amounts. Most of these
gases are from pollution, and almost all the "naturally" occurring gases
are found at levels much higher than what we would have seen 200 years ago
(i.e., before the Industrial Revolution). These are air pockets eventually
turn into the air bubbles in the ice. And if we look at the Greenland Ice
Core Record we can see dramatic increases in pollution over the last 50 to
150 years (different for different gases). We can also see when the
EPA passed the Clean Air Act in the 1970's trying to reduce the amount of
SO2 produced by power plants and factories.
In our study we are actually most interested in the gases coming out of the
snow (and the air pockets in the snow). We have evidence to show
that these gases are being formed by the interaction of sunlight and pollution
in the snow. Barry Lefer, National Center for Atmospheric
Research - writing from Summit
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Georgia Tech measures Nitric Oxide
(NO), Ozone (O3), and sometimes the hydrogen
peroxy radical (HO2 ) in the firn (pore spaces
between the snow grains). NO is usually associated with combustion
of fossil fuels such as car engines, coal plants etc. or can occur naturally
in thunderstorms. Neither source affects the ‘pristine’ air at the surface
of Greenland. So, finding relatively large concentrations of NO (0-300
parts per trillion) in the firn air at Summit comes as a surprise.
Ozone reacts with NO to form nitrogen dioxide NO2
and molecular oxygen O2.
NO + O3
--> NO2 + O2
This reaction results in ozone loss in the firn. NO2
formed by this reaction is a brown gas that is observed in urban smog.
Now the NO2 levels here are much lower than
in cities, so it does not have the brown color but is still chemically active.
Of particular interest is the effect that NOx (NO+NO2)
has on the HOx (OH+HO2) at Summit.
The hydroxyl radical (OH) is often considered the scrubber of the atmosphere.
Most chemical species emitted into the atmosphere (or within the firn) are
in a reduced form and must be oxidized before returning to the surface.
OH is responsible for this process in the atmosphere. Although OH does
most of the "dirty work" it is present in very low concentrations and has
a lifetime of ~1 second. That is why it is helpful to think of OH with
its reservoir species HO2. HO2
is less reactive and ~100 times more abundant. The HO2
present in the firn can react with NO to form OH.
HO2 +
NO --> OH + NO2
Unfortunately OH reacts to quickly in our inlet tube to be measured directly,
but measurements of longer lived species such as HO2
and NO give some insight to the ‘reactivity" of the firn air.
NCAR measures the amount of light at different wavelengths that are important
to chemistry in the lower atmosphere where these measurements are made.
People can see light in the visible spectrum and different wavelengths appear
as different colors to the human eye. However, other wavelengths of
‘light’ make it from the sun to the surface. UV light is the
type that can give people sunburns, but it also initiates a number of chemical
reactions that do not happen in the dark. The term for splitting of
molecular bonds by light is called photolysis. Photolysis of NO2
is very important in determining the reactivity in the snow.
NO2 +
sunlight--> NO + O
The NO reformed can react again with either O3
or HO2 in a continuing cycle. The atomic
oxygen O will also react with O2 to reform
O3.
O + O2
--> O3
This is one of many photolysis reactions that are measured in the snow.
Barry Lefer has a system of 5 probes which are inserted in the firn at different
depths. The measurement of UV and visible light at these different
levels quantifies the available energy to initiate the various reactions occurring
in the firn and causing the emission of NO from the firn to the atmosphere.
- Steve, Dave and Jeff ,
Georgia Tech
- writing from Summit,
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Question: Is there bacteria
in the snow/ice?
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Answer: Yes,
there probably is bacteria at in the snow and ice here at Summit, Greenland.
I do not know of any studies that have proven that there is bacteria here
at Summit, but a few years ago some American scientists discovered bacteria
in the ice at the South Pole. While this is not surprising since bacteria
are everywhere and can be carried long distances in the atmosphere, the
researchers were surprised to find that the microbes were metabolically active
and synthesizing DNA and protein at snow temperatures of -12 to -17 C (10.4
to 1.4 F). The other interesting part of this discovery is that by
looking at the family tree of the bacteria they found that these microbes
were much older than the Antarctic ice sheet, so that it is unlikely that
these microbes evolved to the cold conditions in Antarctica. It seems
likely that the snow bacteria should use some special enzymes and or cell
membrane material to allow them to function at temperatures well below freezing.
Barry Lefer, National Center for Atmospheric
Research - writing from Summit
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Question: Can you discuss
some of the sources of experimental error that you encounter. We are interested
in the most major sources as well as some of the minor sources that are
still pronounced enough that you need to look out for them. Can you describe
a little bit about how you "correct" your data- if that is something that
is done in this case.
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Answer: There
are lots of sources of error in our measurements. For my radiation
measurements the most important error that I try to reduce are calibration
errors. The instrument calibration (or sensitivity) can change over
time. The key to reducing this error is to calibrate often. Right
now I am trying to calibrate every 4-5 days. It takes 4-5 hours to
calibrate, so I usually do this at "night" so a not to miss any data during
the day. Now that night is getting shorter this is getting more difficult.
I also try to calibrate if instrument undergoes a big change (like the other
night when the electrical cord became unplugged and instrument got really
cold) or if data looks a little different than normal. Some of the
changes in calibration are due to the aging of the detector, it becomes less
sensitive over time/exposure to UV photons. This is generally a very
slow change, Other changes in calibration in my instrument are the
result of many hours of use. After continuously scanning the different
wavelengths of ultraviolet and visible light for many days, the gears inside
the instrument start to wear. As this happens the instrument needs
to be re-tuned so that it is scanning the correct range. Eventually
after a couple months, I will have to replace this system in the instrument,
and again this will require a new calibration.
Other sources of error include the measurement of the depth of
the probes in the snow. This is normally not that difficult, but this
spring the wind keeps blowing hard enough to create snow drifts on top of
the probe and so the depth of the probes is changing all the time.
This past Monday, the snow drifted more than 16 inches on top of the probes
in less than 10 hours.
The only major "correction" that I have to make to my data is that I
am measuring the sunlight coming down from above. Occasionally, I flip
the instrument upside down so that it is measuring the sunlight coming up
from the snow. Luckily, this is a fairly constant ratio. So
to get the total intensity of the sunlight, I multiply my uplooking measurements
by this ratio. Barry Lefer, National Center for Atmospheric
Research - writing from Summit
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Barry cleaning his cloud camera
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