2016 Expeditions

We will be performing maintenance on the neutron monitors. The neutron monitors are used to study the sun, which occasionally undergoes solar storms that produce bursts of energetic particles. We are interested in learning more about the energy range and abundance of the particles produced in these events, which is important for understanding how to protect electronics and the electrical grid from extreme space weather events.

¿Qué están haciendo?

CosRay: Monitoreo de Neutrones

Nuestro trabajo consistirá en dar mantenimiento a los monitores de neutrones. Estos sensores son utilizados para estudiar al sol, el cual produce ocasionalmente tormentas solares en las que emite partículas de gran energía. Nos interesa aprender más sobre el rango energético de éstas partículas, asi como sobre su abundancia, ya que esto nos permitirá predecir mejor las tormentas solares y así podr proteger equipos electrónicos y las redes eléctricas acá en la tierra.

The team will travel daily to Weddell seal haul out sites on the sea ice near McMurdo Station. While on location, the team will find female seals that they had handled approximately two months earlier, and recapture the females to assess changes in their health, condition and behavior over the summer months. To do so, the seals will be captured and sedated. Once sedated, the seals will be weighed and measured (length and girth), have blood and tissue samples collected, and their molt status assessed. In addition, imaging ultrasound will be used to determine if the females are pregnant, and -0 if so - the size of the fetus will be measured. They will also take thermal images of the seals to see how much heat the seal is losing to the environment. Time-depth recorders that had been deployed earlier in the summer will be recovered, and the diving and foraging behavior of the seals during the past two months examined. The team will return the next season in an attempt to relocate the seals and determine if the seals have pupped.

In addition, the team is doing range-wide surveys of all the seals in the area to determine the timing and progression of the molt (when it starts, how long it lasts). During each survey the molt status of all seals seen is recorded, and the status referenced back to the timing of pupping and reproductive activities to determine if females that finish lactation earlier start molting earlier.

The project's overall goals are to learn more about what drives the timing of a seal’s critical life history events – such as breeding and molting – and how disruptions in that natural cycle by changes in climate and environment might affect the world’s southernmost mammal.

IceBridge, a six-year NASA mission, is the largest airborne survey of Earth's polar ice ever conducted. IceBridge uses a highly specialized fleet of research aircraft and the most sophisticated science instruments ever assembled to characterize yearly changes in thickness of sea ice, glaciers, and ice sheets in the Arctic and Antarctic. The research team is experiencing first-hand the excitement of flying a large research aircraft over the Greenland Ice Sheet. While in the air they are recording data on the thickness, depth, and movement of ice features, resulting in an unprecedented three-dimensional view of ice sheets, ice shelves, and sea ice. Operation IceBridge began in 2009 to bridge the gap in data collection after NASA's ICESat satellite stopped functioning and when the ICESat-2 satellite becomes operational later in 2016, making IceBridge critical for ensuring a continuous series of observations of polar ice. IceBridge flies over the Arctic and Antarctic every year — in the Arctic from March to May and the Antarctic in October and November. By comparing the year-to-year readings of ice thickness and movement both on land and on the sea, scientists can look at the behavior of the rapidly changing features of the polar ice and learn more about the trends that could affect sea-level rise and climate around the globe. More information about IceBridge can be found at the NASA project website. http://www.nasa.gov/icebridge

The research focuses on the interactions between plants and their pollinators, which are animals that aid in plant reproduction through transporting pollen. The aim is to understand how changes in temperature and precipitation may influence plant-pollinator interactions and plant reproduction. Temperature and water availability may alter the timing of flowering and floral traits that attract pollinators, such as nectar volume and flower size. In addition, temperature may alter what pollinator species visit flowers and how often they visit. The combination of these effects on plants and pollinators may influence plant reproduction, measured as the number of fruits and seeds a plant produces. The researchers hope to relate changes in the abiotic environment to floral attractive traits, pollinator visitation, and ultimately the reproductive success of plants. Three focal plant species, blueberry, harebell, and dwarf fireweed are used because they are common in the area and flower at different times of the season.

This work can have important pan-Arctic and global implications. The majority of flowering plants in nature and one third of our crop plants depend on pollinators to produce fruits and seeds. As temperatures rise in the Arctic, successful adaptation and range expansion of many plants, including plants migrating into the Arctic, will depend on pollinators. This study will help us determine which mechanisms may most strongly drive changes in plant-pollinator interactions and plant reproduction.

Microbial diversity has recently been found to show a pattern of organization at various scales. The research team attempts to answer three basic questions about microbial diversity and dispersal, focused on the long-term aspects of dispersal events and climate change: 1) How does environment influence microbial community composition and rate of function? For example, how quickly they convert organic material to carbon dioxide. 2) How are distribution patterns of microbial communities in lakes, streams, and soils influenced by the dispersal from local water flow? 3) How are the shifts in microbial community composition related to shifts in environmental conditions over time such as those caused by climate change?

The goal of our project is to understand how terrestrial ecosystems influence permafrost temperatures. There are places in the Arctic where climate is warming but permafrost temperatures are stable, while at other places permafrost temperatures are rising rapidly with climate. Soil and vegetation that sit on top of permafrost can either promote heat transfer or act as insulators. Our project will use field measurements at research sites throughout Alaska and Siberia to identify broad trends in relationships between ecosystems and permafrost temperature dynamics. At research sites in Siberia we will make detailed measurements to identify the processes responsible for these trends. This work will help to understand the effects of Arctic vegetation change on permafrost temperatures.

The Arctic Ocean is one of the most remote locations on Earth and the area where the impact of climate change may be most strongly expressed. In the Chukchi Borderlands (CBL) area, water masses from the Arctic, Pacific and Atlantic oceans meet and interact over tremendously complex bottom topography, creating intricate currents and sea ice drifts. It is also the region of the most dramatic summer sea ice meltdown in the last decades. This project is a multi-disciplinary group effort to explore marine communities from microbes to mammals and from sea ice to seafloor in this poorly known, bathymetrically and hydrographically complex Arctic region. We will use a combination of photographic mapping using ROV, physical sampling, and state-of-the-art metagenomics to assess the diversity of this region. Field work involves a ~30-day icebreaker cruise in the summer of 2016, with use of the ROV Global Explorer that provides unique opportunities to capture fragile pelagic organisms and observe benthic fauna in relation to the bathymetric and geomorphological features of the seafloor.

Team Announcement: Due to unexpected circumstances, Ivy McDaniel will not be going to the field this season with the research team.

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 sinking 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 is altered. Sunlight can photo-degrade or break-down organic carbon and alter the carbon's ability to support bacterial respiration to produce carbon dioxide. Whether sunlight and UV exposure will enhance or retard the conversion of newly exposed carbon to carbon dioxide is currently unknown—this study 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 understand 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 is accomplishing 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.

The carbon cycle is the means by which carbon is moved between the world's soils, oceans, atmosphere, and living organisms. Northern tundra, permafrost, ecosystems play a key role in the carbon cycle because the cold, moist, and frozen soils trap organic material and slow their decomposition. This very slowly decaying organic material has caused carbon to build up in the Arctic during the past thousands of years. Historically, the tundra has stored large amounts of carbon because soil decomposition in permafrost was very slow. Now, warming in the Arctic is causing the permafrost to thaw and the tundra to become warmer and dryer. As the earth warms and permafrost thaws, this previously frozen carbon is released as carbon dioxide and goes into the atmosphere, turning the tundra into a source of carbon, rather than a sink. We are using carbon isotope techniques to measure how much carbon comes directly from soil decomposition and how much comes from plant respiration. This will help us understand more about the source/sink dynamics of the tundra. Little is known about respiration in the arctic winter, but our winter sampling is improving. With more data we will have a better idea of how much carbon is lost during the long, dark winter. Together our summer and winter data will help improve global carbon models by adding a more realistic representation of the Arctic. Because carbon dioxide is a greenhouse gas, any additional carbon dioxide lost from permafrost ecosystems creates a positive feedback that leads to even further warming.

More information about the project can be found here: https://www2.nau.edu/schuurlab-p/index.html

Below the surface of arctic tundra is a matrix of soil, roots, and fungal hyphae that may play a critical role in the trajectory of future climate change. For millennia arctic plants have persisted in cold, wet, and shallow soils underlain with permafrost, permanently frozen ground, in many regions of the Arctic. However, with unprecedented warming in the last century, these plants may see the amelioration of their harsh, belowground environment. With a warming climate, the depths to which permafrost soils thaw each summer increase, potentially providing greater access to drier and more nutrient rich soil resources. Yet, whether arctic plants and their obligate, fungal root-symbionts have the capacity to respond rapidly and exploit soil resources as frozen, high-latitude soils thaw is unknown. Our research investigates the opportunistic capacity of arctic plants and their fungal symbionts to explore a newly available soil environment. Our goal is to uncover the role that the belowground response to a warming world may play in mitigating feedbacks between thawing permafrost and the atmosphere.

This project focuses on an important group of photosynthetic algae in the Southern Ocean (SO), diatoms, and the roles associated bacterial communities play in modulating their growth. Diatom growth fuels the food web in the SO and balances atmospheric carbon dioxide by sequestering the carbon used for growth to the deep ocean on long time scales as cells sink below the surface. The diatom growth is limited by the available iron in the seawater, most of which is not freely available to the diatoms but instead is tightly bound to other compounds. The nature of these compounds and how phytoplankton acquire iron from them is critical to understanding productivity in this region and globally. The investigators will conduct experiments to characterize the relationship between diatoms, their associated bacteria, and iron in open ocean and inshore waters. Experiments will involve supplying nutrients at varying nutrient ratios to natural phytoplankton assemblages to determine how diatoms and their associated bacteria respond to different conditions. This will provide valuable data that can be used by climate and food web modelers and it will help us better understand the relationship between iron, a key nutrient in the ocean, and the organisms at the base of the food web that use iron for photosynthetic growth and carbon uptake.

The objective of our project is to understand the behavior of the McMurdo Shear Zone (SZ) in Antarctica through a four year integrated study involving field observation, satellite remote sensing, and numerical modeling. The SZ is a section of heavily crevassed ice that separates the slow-moving McMurdo Ice Shelf (MIS) from the larger fast-flowing Ross Ice Shelf (RIS). Previous mapping of crevasses in the SZ indicates the potential for unstable behavior. Our project will carry out GPS surveys to study the surface deformation across the SZ and Ground Penetrating Radar surveys (GPR) to obtain detailed maps of crevasse extent and orientation. Because the shear zone is intensely crevassed, and hence dangerous for surface travel, we will perform the GPR surveys using an autonomous robot. The field observations will be used to develop a numerical model of the shear zone’s behavior and simulate future scenarios of its influence on ice shelf stability.

The SZ provides a critical amount of lateral support for the RIS. A potential weakening of this area could reduce the amount of backstress provided by the RIS on inland ice which would increase the flux of ice across the grounding line and thereby accelerate the ice sheet’s contribution to sea level rise. Logistic support of the US Antarctic Program’s South Pole station also relies on an overland traverse from McMurdo which must cross the SZ. Our work will provide a means of predicting future SZ behavior and provide a timeframe to plan alternative routes if necessary.

Since the first expeditions to the poles, scientists have compiled a long list of polar taxa that have unusually large body sizes. This phenomenon is known as polar gigantism, and biologists have proposed many hypotheses to explain it. The most broadly-accepted idea is the ‘oxygen hypothesis,’ which states that polar gigantism stems from a combination of high oxygen availability in the ocean and low metabolic rates because of the extreme cold temperatures. In combination, these two factors are thought to allow animals to be giants by making it comparatively easy to get enough oxygen from the environment to support large bodies. The links between body size, environmental oxygen availability, and performance have been used to argue that as marine and aquatic environments warm, giants will be among the first to disappear. We are looking at these tradeoffs and the validity of the size-vulnerability hypothesis using Antarctic pycnogonids (sea spiders), which contain spectacular examples of polar gigantism. Visit the researcher's working group website to learn more information on this topic.

IceBridge, a six-year NASA mission, is the largest airborne survey of Earth's polar ice ever conducted. IceBridge uses a highly specialized fleet of research aircraft and the most sophisticated science instruments ever assembled to characterize yearly changes in thickness of sea ice, glaciers, and ice sheets in the Arctic and Antarctic. The research team will experience first-hand the excitement of flying a large research aircraft over the Greenland Ice Sheet. While in the air they will record data on the thickness, depth, and movement of ice features, resulting in an unprecedented three-dimensional view of ice sheets, ice shelves, and sea ice. Operation IceBridge began in 2009 to bridge the gap in data collection after NASA's ICESat satellite stopped functioning and when the ICESat-2 satellite becomes operational in 2016, making IceBridge critical for ensuring a continuous series of observations of polar ice. IceBridge flies over the Arctic and Antarctic every year — in the Arctic from March to May and the Antarctic in October and November. By comparing the year-to-year readings of ice thickness and movement both on land and on the sea, scientists can look at the behavior of the rapidly changing features of the polar ice and learn more about the trends that could affect sea-level rise and climate around the globe. More information about IceBridge can be found at the NASA project website. http://www.nasa.gov/icebridge

How do you find something that isn't directly visible? That's the challenge faced by the team who 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 100,000 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.

The McMurdo Dry Valleys Long-Term Ecological Research (MCM LTER) Program is an interdisciplinary and multidisciplinary study of the aquatic and terrestrial ecosystems in an ice-free region of Antarctica. MCM joined the National Science Foundation's LTER Network in 1993 and is funded through the Office of Polar Programs in six year funding periods. The McMurdo Dry Valleys (77°30'S 163°00'E) on the shore of McMurdo Sound, 2,200 miles (3,500 km) due south of New Zealand, form the largest relatively ice-free area (approximately 4,800 sq km) on the Antarctic continent. These ice-free areas of Antarctica display a sharp contrast to most other ecosystems in the world, which exist under far more moderate environmental conditions. The perennially ice-covered lakes, ephemeral streams and extensive areas of exposed soil within the McMurdo Dry Valleys are subject to low temperatures, limited precipitation and salt accumulation. The dry valleys represent a region where life approaches its environmental limits, and is an end-member in the spectrum of environments included in the LTER Network. The overarching goal of MCM LTER research is to document and understand how ecosystems respond to environmental changes.

Neutron monitors are used to study cosmic rays, and indirectly the sun, which occasionally undergoes solar storms that produce bursts of energetic particles. We are interested in learning more about the energy range and abundance of the particles produced in these events, which is important for understanding how to protect electronics and the electrical grid from extreme space weather events. The McMurdo deployment will involve dismantling two neutron monitors and if possible, the South Pole deployment will be to perform routine maintenance.