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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.

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.

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 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.

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.

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

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.

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?