Beneficiaries and their projects
|Armin Sigmund, EPFL||Measuring snow sublimation, transport, and accumulation near Princess Elisabeth Station, Antarctica|
|Dr. Cameron Hudson, EAWAG||Exploring evolutionary and ecological solutions to DHA deficiency during colonization of freshwater by marine fish in South Greenland|
|Fien De Doncker, University of Lausanne||Sediment samples and bathymetry to constrain erosion rates and their relationship with sliding velocities|
|Dr. Julie Lattaud, ETHZ||Arctic expedition on ice breaker Amundsen in the Beaufort Sea|
|Dr. Laurel Thomas Arrigo, ETHZ||Coupled biogeochemical cycles of Fe and C during redox cycling in Fe-rich wetland soils of Iceland|
|Dr. Michael McCarthy, WSL||Measuring sublimation in a high-altitude glacierised catchment of the dry Andes|
|Suryanarayanan Balasubramanian, University of Fribourg||Artificial Ice Reservoirs Measurement Campaign|
Project: Measuring snow sublimation, transport, and accumulation near Princess Elisabeth Station, Antarctica
Keywords: Sublimation, sea level rise, snow cover, surface mass balance, blowing snow
To predict the future sea level in a warming climate, we need to understand and simulate the exchange of water and ice between the polar ice sheets and the ocean. This exchange either takes place directly through glacier movement and melt or indirectly through processes such as snowfall, sublimation (transition from snow or ice to water vapor), and vapor deposition (the opposite of sublimation). The contributions of sublimation and vapor deposition are highly uncertain because snow transport by the wind can strongly amplify these processes but measurements and simulations become challenging in these conditions. During intense storms, a considerable amount of vapor deposition may occur in the near-surface atmosphere and partly offset the sublimation of blowing snow at greater heights. This phenomenon has not been sufficiently explored. Although strong winds are common in Antarctica, their effect on snow transport and sublimation is strongly simplified in continental-scale simulations.
The field trip to Princess Elisabeth Station, Antarctica, aims at further developing two measurement stations, which will automatically record high-quality weather and snow data during at least one year. The installation of new instruments will improve the accuracy of sublimation estimates and allow us to detect even shallow snow transport layers close to the surface. Temporary measurements of snow density and changes in snow surface elevation in the surrounding area will complement the data set and help to validate simulation results.
In combination with measurements from two other Antarctic sites, the data will be used to improve the representation of snow transport and sublimation in simulations of the Antarctic mass balance. In this way, the project will contribute to more reliable predictions of the Antarctic weather and climate and the associated sea level rise.
Dr. Cameron Hudson
Project: Exploring evolutionary and ecological solutions to DHA deficiency during colonization of freshwater by marine fish in South Greenland
Keywords: Polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA), threespine stickleback, fatty acid desaturase 2 (FADS2), morphological adaptation, foraging, colonization, nutritional constraints, whole genome sequencing
Polyunsaturated fatty acids (PUFAs) are essential nutrients, but they differ in abundance within and between habitats. They are abundant in marine environments, but less so in freshwater, and this poses a challenge for fish species that colonize freshwater from the ocean. As the environment changes, it is likely that we will observe range expansions and colonizations by marine fish. This is particularly relevant in the Arctic, where the melting of glaciers will create new freshwater habitats that lack fish. To survive in these new habitats, fish must evolve adaptations to obtain the essential nutrients that they need. One important PUFA, docosahexaenoic acid (DHA), is crucial for its role in neural development of vertebrates, and is essential for survival. Organisms can either obtain DHA directly from their diet, or synthesize it from other fatty acids. Some fish species have shown a duplication in the FADS2 gene, which helps them synthesize more DHA, while others are morphologically adapted to forage on DHA rich prey. With this project, we aim to investigate these two evolutionary adaptations that fish evolve to obtain DHA when colonizing freshwater habitats.
The melting of glaciers and associated changes in sea level have provided opportunities, and created barriers, for species to shift their range or colonize new habitats. Threespine stickleback (Gasterosteus aculeatus) are a marine fish species that have repeatedly colonized freshwater around the northern hemisphere. In Greenland, freshwater habitats only became accessible to fish after the melting of glaciers, between 20,000-12,000 years ago, so we have a rough estimate of the age of freshwater populations. During this field campaign, we plan to collect freshwater stickleback from populations of different age throughout Southern Greenland. Once back in the lab we will determine the number of FADS2 genes they possess, compare this to their DHA content from muscle tissue, and measure morphological traits related to prey capture efficiency. By studying Greenlandic stickleback populations, we will learn more about how aquatic organisms evolve when faced with nutritional constraints.
Fien De Doncker
Project: Sediment samples and bathymetry to constrain erosion rates and their relationship with sliding velocities
Keywords: Erosion/sedimentation, bathymetry, sonar, sediment cores, sub-bottom profiles
Sediments produced by erosion play a fundamental role in Earth systems through their influence on the global carbon cycle and marine and freshwater ecosystems. This is particularly pronounced in Arctic regions. In that context, Greenland may account for 8% of the global sediment export to oceans, and this number is likely to increase due to climate warming. To forecast how this number will change in the future, we need to understand how the Greenland Ice Sheet generates and exports sediments. Our goal is twofold: we want to understand how the ice carves out the underlying rocks (bedrock erosion) and how meltwater transports this eroded material to the ocean.
We will test whether there is a relationship between glacial erosion and ice sliding velocity. In the absence of widespread measurements to quantify bedrock erosion, we will take sediment cores in bays of West-Greenland and measure the dept of the ocean floor. To quantify the ice sliding velocity for the glaciers around these bays, we will use satellite imagery and ice sheet models. If we find a relationship between ice sliding velocity and bedrock erosion rates, we will be in a position to forecast ice sliding velocities and in turn estimate how the sediment export of Greenland will evolve.
Dr. Julie Lattaud
Project: Arctic expedition on ice breaker Amundsen in the Beaufort Sea
Keywords: Paleoclimate reconstructions, Beaufort Sea, methane, microbial changes, biomarkers
Methane emissions in the Arctic region are expected to rise due to thawing permafrost and global increase in temperature and, while they are increasingly studied on land, their marine counterpart is still understudied. The link between marine ecosystem changes, thawing of subsea permafrost and methane emission in the Arctic Ocean is currently insufficiently understood. A planned expedition to the Beaufort Sea on board the Canadian ice breaker Amundsen offers the unique opportunity to collect samples from the water column as well as surface sediments and longer sediment cores (Holocene timescales, about 10 000 years).
Bacteria and Archaea phylum contain many species involved in the methane cycle and these phylum have specific membrane lipids, so-called biomarkers that are remarkably stable after the death of the organisms and can be found in settling particles in the water column and in the underlying sediment. These biomarkers are specific for a class of organism or a metabolism and their abundances can be studied using top-of-the-art instruments. These new samples will bring new knowledge and understanding of the how the methane cycle evolves under the ongoing rapid anthropogenic climate changes and how it varied under the slower (geological timescales) climatic changes recorded since the Holocene.
Dr. Laurel Thomas Arrigo
Project: Coupled biogeochemical cycles of Fe and C during redox cycling in Fe-rich wetland soils of Iceland
Keywords: Biogeochemical cycles, climate change, iron biogeochemistry, soil organic carbon, hydrologic regimes
On volcanic islands, rapid weathering of tephra parent materials results in volcanic soils (Andosols) with a high abundance of poorly-crystalline iron and aluminum minerals. Owing to their high specific surface area and thus high capacity for sorption, poorly-crystalline mineral phases are important to storage of soil organic carbon (SOC). In the Andosols of Iceland, SOC immobilization is further augmented by cooler climates, which slow microbial turnover rates. However, changing climate patterns are expected to alter the hydrologic regimes of high latitude soils, thus changing the frequency of redox cycles and microbial activity. Because mobilization of SOC is coupled to the reductive dissolution of (poorly-crystalline) iron minerals under reducing conditions, increased redox-cycling in Iceland’s Andosols is likely to influence iron and carbon cycling and storage.
In this project, in-situ field experiments combined with laboratory-based soil incubation studies will probe the coupled biogeochemical cycles of iron and carbon in organic-rich Andosols of Iceland. The data gathered here will help to understand SOC storage potential of high latitude Andosols; information which is critical to accurately predict global carbon cycling under changing climate patterns.
Dr. Michael McCarthy
Project: Measuring sublimation in a high-altitude glacierised catchment of the dry Andes
Keywords: Sublimation, snow, glacier, glacio-hydrological modelling, water resources
The dry Andes are one of the most vulnerable mountain regions of the world to water stress as a result of climatic change. Here, glaciers and snow are a vital water resource, storing precipitation during the wet season and releasing it to buffer river flows when most needed by local people during the dry season and droughts.
Using glacio-hydrological models, we can simulate how glaciers, snow and river flows change in response to changes in climate. However, a process that is often not represented in these models, largely due to a lack of observations, is sublimation - the process by which ice turns directly into vapour without passing through a liquid phase.
This omission can have important consequences. Calibrating a glacio-hydrological model that does not account for sublimation to measurements of snow or glacier change that have been made where sublimation has occurred may cause simulated river flows to be overestimated and therefore unreliable.
This project will make detailed measurements of sublimation on the Tapado glacier complex in the Norte Chico region of northern Chile, using both traditional methods and new, low-cost systems. In doing so, it will facilitate improved simulation of sublimation, and therefore snow and glacier change and downstream hydrology, in a state-of-the-art glacio-hydrological model.
Project: Artificial Ice Reservoirs Measurement Campaign
Keywords: Albedo, cryosphere, geoengineering, icestupa, energy balance model, water storage technology
Glaciers and seasonal snow cover are expected to change their water storage capacity with major consequences for downstream water supply. The challenges brought about by these changes are especially important for mountain communities, which directly rely on the seasonal glacial melt cycle for their farming needs. Some villages, mainly in the region of Ladakh, have been using Artificial Ice Reservoirs (also called as Icestupas) as a tool to adapt to these changes.
Artificial Ice Reservoirs (AIR) are economically feasible and energy neutral making them a great asset for climate change adaptation measures. The main purpose of AIR is irrigation. The water contained in the ice reservoirs should be released during the growing season. To fulfill this requirement, AIR are constructed in higher altitudes, in shadowed zones and shaped according to requirement.
Although many villages have been constructing AIR, there does not exist any reliable estimate of the water discharged by AIR to date. Also the construction decisions used are based on qualitative rather than quantitative judgements. Thus, development of a predictive model that can provide quantitative melt water estimates is crucial if this technology is to become a viable water resource management strategy.
It is the aim of this research project to do so by documenting the formation and melting process of AIR through field measurements and physical modelling approaches. Apart from estimating AIR water storage potential worldwide, this project further aims to quantify and guide construction decisions around location, water discharge and fountain design.