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It's hard to imagine that anything could live in the cold, dry soils of Antarctica. Early investigations of the soil bacterial communities of the McMurdo Dry Valley found only a handful of bacteria, leading to the conclusion that these soils were essentially sterile. The idea that microorganisms can grow at all in the very dry soils of the McMurdo Dry Valleys seems astounding but the recent use of advanced molecular biology techniques to investigate soil biodiversity has revealed a surprising bacterial richness in the area.

The goal of this project was to identify active members of the McMurdo Dry Valley soil microbial community and determine their ecological role. Little is known about bacterial populations in the Dry Valley soils, but until it is understood which populations are active and what they do, it is impossible to understand the ecological role that bacteria play in ecosystem function.

Antarctic notothenioid fishes are uniquely adapted to life in the extreme conditions of the Southern Ocean. Waters surrounding Antarctica are unlike any other. The Southern Ocean is isolated from other oceans by the Antarctic Circumpolar Current, it is very cold with temperatures at or near -1.8 degrees Celsius, and the water is rich in oxygen. Notothenioids have evolved many physiological traits that enable them to survive in this remarkable environment. They lack a swim bladder and have antifreeze proteins that prevent their bodies from freezing. Members of one family of notothenioids, the Channichthyidae (icefishes), are unique among all vertebrates because they lack the circulating oxygen-binding protein, hemoglobin.

The loss of hemoglobin is considered a neutral mutation; one that neither enhances nor reduces fitness. However, the team hypothesizes that the loss of hemoglobin may be an advantage because hemoglobin promotes the formation of reactive oxygen species that damage macromolecules. Overall, the team's research was aimed at understanding the unique physiological and biochemical traits that have arisen in fishes during their evolution in the chronically cold waters of the Southern Ocean.

This project investigated the marine system of the Totten Glacier and Moscow University Ice Shelf, East Antarctica which has shown a recent increase in ice loss. This system is of critical importance because it drains one-eighth of the East Antarctic Ice Sheet and contains a volume equivalent to nearly 7 meters of potential sea level rise, greater than the entire West Antarctic Ice Sheet. This rarely explored region is the single largest, least understood, and potentially unstable marine glacial system in the world. Despite intense scrutiny of marine-based systems in the West Antarctic Ice Sheet, little is known about the Totten Glacier system.

This project conducted a ship-based marine geologic and geophysical survey of the region, combined with a physical oceanographic study. The results have added to our understanding of the oceanographic and glacial system and its potentially sensitive response to environmental change. This endeavor complemented studies of other Antarctic ice shelves, oceanographic studies near the Antarctic Peninsula, and ongoing development of ice sheet and other ocean models.

How do you find something that isn't directly visible? That's the challenge faced by the team that developed the IceCube neutrino detector under the ice at the South Pole. Just as X-rays allow us to see bone fractures and MRIs help doctors find damage to soft tissue, neutrinos will reveal new information about the Universe that can't be seen directly. The in-ice particle detector at the South Pole records the interactions of neutrinos which are nearly massless sub-atomic messenger particles. Neutrinos are incredibly common (about 100 trillion pass through your body as you read this) subatomic particles that have no electric charge and almost no mass. They are created by radioactive decay and nuclear reactions, such as those in the Sun and other stars. Neutrinos rarely react with other particles; in fact, most of them pass through objects (like the earth) without any interaction. This makes them ideal for carrying information from distant parts of the universe, but it also makes them very hard to detect.

All neutrino detectors rely on observing the extremely rare instances when a neutrino does interact with a proton or neutron. This transforms the neutrino into a charged particle of the same type as the neutrino flavor (electron, muon, or tau). Muons are charged particles that can travel for 5-10 miles (8-16 kilometres) through matter depending on their energy, and generate detectable light in translucent media.

IceCube is made up of thousands of sensitive light detectors embedded in a cubic kilometre of ice between 1450 m and 2450 m below surface. The sensors are deployed on strings in the ice holes that were made using a hot water drill. IceCube detects about 300,000 neutrinos a year, and has a projected life time of two decades. The data collected will be used to make a "neutrino map" of the universe and to learn more about astronomical phenomena, like gamma ray bursts, black holes, exploding stars, and other aspects of nuclear and particle physics. However, the true potential of IceCube is discovery; the opening of each new astronomical window leads to unexpected discoveries.

In the Arctic, bright summers and dark winters are a fact of life and can lead humans to rely on clocks and routines to tell them when to eat or sleep, but how do animals function under these conditions? Circadian rhythms refer to the "internal body clock" that regulates the approximately 24-hour cycle of biological processes in animals and plants. Rhythms in body temperature, brain wave activity, hormone production, and other biological activities are linked to this 24-hour cycle. The Earth's light-dark cycle provides the strongest influence on circadian rhythms and is thought to be the primary driver for the emergence and evolution of internal clocks. In the Polar Regions, however, photoperiod exhibits extreme annual variation because of near 24 hour sunlight in the summer and 24 hour darkness in the winter. In the absence of a well-defined light-dark cycle, some arctic residents lose their daily organization of behavior and physiology, and it is thought that the molecular clockwork that drives circadian rhythms may be weak or absent in arctic vertebrates.

The research team has recently found that the arctic ground squirrel displays daily rhythms of body temperature throughout the arctic summer, in the absence of a light-dark cycle. The current study continues investigate the circadian rhythms in arctic ground squirrels during the continuous daylight present during the active summer season and continuous dark of the 6-8 months of hibernation spent sequestered in a burrow. The team wants to understand why arctic ground squirrels, unlike other arctic vertebrates, appear to maintain 24-hour rhythms during the active season. They hypothesize that the persistence of circadian rhythmicity allows ground squirrels to reduce energy expenditure by anticipating predictable changes in its immediate surroundings. They continue to test their hypothesis by experimentally phase-shifting free-living ground squirrels to be active at 'night' and estimating their subsequent rates of energy expenditure.

Tremendous stores of organic carbon frozen in permafrost soils have the potential to greatly increase the amount of carbon in the atmosphere. Permafrost soils may thaw sporadically, and melting ground ice can cause land-surface subsidence called "thermokarst failures". These failures change the rate and amount of carbon released with the unanticipated outcome being that soil carbon can be mixed-up from a depth and exposed to sunlight as the land surface fails. Sunlight can photo-degrade organic carbon and alter the carbon's ability to support bacterial respiration to produce carbon dioxide. Whether UV exposure will enhance or retard the conversion of newly exposed carbon to carbon dioxide is currently unknown—in this study team is providing the first evidence that this alteration will be amplified by photochemical processes and their effects on microbes.

The research team is trying to understanding exactly how sunlight and bacteria degrade dissolved organic matter by determining how fast these processes convert newly released dissolved organic matter to carbon dioxide, compared to dissolved organic matter already in surface waters. The team will accomplish their research objectives with a series of laboratory experiments to determine rates of photodegradation and microbial processing of dissolved organic matter from different sources, and a series of landscape comparisons and sampling transects to characterize dissolved organic matter degradation in small basins and large rivers extending from the headwaters to the Arctic Ocean. Ultimately, this research will attempt to answer questions such as whether carbon export from tundra to oceans will rise or fall and how reactive the exported carbon will be. The team hopes to be able to measure the ultimate impact of impending disturbances, including climate change, on the net carbon balance of the Arctic and its interaction with the global carbon cycle.

This project examined the poorly-understood interaction of climate change and microbial methane production in wetland soils in the Lapland region of Finland. The research team conducted field and lab experiments to determine the role of arctic wetlands in global carbon cycling. Similar experiments have also been completed by the research group in the Alaskan arctic, making this project part of an investigation into the potential global-scale response of arctic wetlands to impending climate changes.

The Arctic is experiencing the most dramatic warming due to climate change of all global systems. As arctic soils warm, the resulting rise in microbial activity increases emissions of carbon dioxide and methane, further accelerating global climate change. Because the vast majority of global carbon is stored in soils, and soil carbon is in flux with atmospheric carbon, soil microbes can either alter or exacerbate climate changes.

Methane is a powerful, carbon-based greenhouse gas, and wetlands are the largest natural source of methane to the atmosphere, but factors that influence net methane emissions from arctic wetland soils are not well understood. The Lapland region of northern Finland offered an ideal research environment because it has carbon-rich arctic wetlands different from those that exist in North America, offering the opportunity to comparatively study the controls on methane flux from arctic wetland ecosystems. More generally, carbon cycling research is critical for building accurate global climate models, which inform social and international climate change mitigation policies.

This project sought to understand the formation of drumlins, some of the most mysterious and poorly understood of glacial landforms. Drumlins are elongated, aligned hills that form hidden from view beneath glaciers. The first modern drumlin field has recently been exposed by the retreat of Múlajökul. Previously this kind of landform could be studied only by focusing on drumlin fields that formed long ago in the Pleistocene, so this study provided a unique opportunity to understand drumlin formation better.

The research team collected intact till (rocks and finely ground material picked up by a glacier, and deposited as sediment along its path) samples from the drumlins and the surrounding area. The samples were taken back to Iowa State University and the University of Wisconsin Milwaukee and subjected to geotechnical tests and magnetic fabric analyses. This testing determined the former distribution of stresses on the till and patterns of subglacial till deformation that were likely central to the formation of the drumlins. In addition to helping determine the internal structure of drumlins and how drumlins form, this research will shed light on the distribution of basal drag beneath glaciers—an important and poorly understood factor in their dynamics.