Periodic Reporting for period 2 - DEEP PURPLE (DEEP PURPLE: darkening of the Greenland Ice Sheet)
Okres sprawozdawczy: 2020-10-01 do 2022-03-31
The stability of the Greenland Ice Sheet (GrIS) is a threat to coastal communities worldwide. The PIs have changed our understanding of why it darkens during the melt season, becoming increasingly deep purple due to pigmented ice algal blooms in the ice surface, producing more melt and accelerating the GrIS towards its tipping point, and increasing sea level.
The next step jump in our understanding of biological darkening will be provided by DEEP PURPLE, which will establish the factors that control ice algal blooms. These factors are essential for modelling of future melting, which require a process-based understanding of blooming. DEEP PURPLE will quantify the synergies between the biology, chemistry and physics of ice algae micro-niches in rotting, melting ice, and examine the combination of factors which stabilise them.
State-of-the-science analytical and observational methods will be employed to characterise the complex mosaic of wet ice habitats, dependent on factors such as the hydrology, nutrient status, particulate content and light fields within these continually evolving ice-water-particulate-microbe systems. We will quantitatively assess why and how the fine light mineral dust particulates contained within the melting ice amplify the growth of ice algae.
The particulate content and composition of different layers in the GrIS is dependent on age, and so the algae that the melting ice can support may fundamentally change over time. We look back to understand if the ice biome has changed through the Anthropocene via analyse of fjord sediments. The first draft genome of ice algae will show their key adaptations to glacier surface habitats. DEEP PURPLE looks forward by providing the critical field data sets and conceptual models of ice algal growth that will facilitate the next generation of predictive models of sea level rise due to biologically enhanced melting of the GrIS.
DEEP PURPLE aims to investigate the physical and microbial processes that darken the Greenland Ice Sheet (GrIS) and accelerate sea level rise, with the following principal objectives:
1. To make contemporaneous measurements of the biological, geochemical and physical factors effecting surface darkening at sites across the GrIS, including the relatively frigid north of the Dark Zone, towards the interior of the ice sheet and at sites in the relatively mild south.
2. To gain process information on the limits and stimulation of darkening from a southern site, and the potential for further darkening from the northern and the interior areas of the GrIS.
3. To examine interactions between ice algae, mineral dust (including black carbon) concentrations, and test their relative importance and synergies in surface darkening.
The next step jump in our understanding of biological darkening will be provided by DEEP PURPLE, which will establish the factors that control ice algal blooms. These factors are essential for modelling of future melting, which require a process-based understanding of blooming. DEEP PURPLE will quantify the synergies between the biology, chemistry and physics of ice algae micro-niches in rotting, melting ice, and examine the combination of factors which stabilise them.
State-of-the-science analytical and observational methods will be employed to characterise the complex mosaic of wet ice habitats, dependent on factors such as the hydrology, nutrient status, particulate content and light fields within these continually evolving ice-water-particulate-microbe systems. We will quantitatively assess why and how the fine light mineral dust particulates contained within the melting ice amplify the growth of ice algae.
The particulate content and composition of different layers in the GrIS is dependent on age, and so the algae that the melting ice can support may fundamentally change over time. We look back to understand if the ice biome has changed through the Anthropocene via analyse of fjord sediments. The first draft genome of ice algae will show their key adaptations to glacier surface habitats. DEEP PURPLE looks forward by providing the critical field data sets and conceptual models of ice algal growth that will facilitate the next generation of predictive models of sea level rise due to biologically enhanced melting of the GrIS.
DEEP PURPLE aims to investigate the physical and microbial processes that darken the Greenland Ice Sheet (GrIS) and accelerate sea level rise, with the following principal objectives:
1. To make contemporaneous measurements of the biological, geochemical and physical factors effecting surface darkening at sites across the GrIS, including the relatively frigid north of the Dark Zone, towards the interior of the ice sheet and at sites in the relatively mild south.
2. To gain process information on the limits and stimulation of darkening from a southern site, and the potential for further darkening from the northern and the interior areas of the GrIS.
3. To examine interactions between ice algae, mineral dust (including black carbon) concentrations, and test their relative importance and synergies in surface darkening.
Two field seasons have been undertaken in southernmost Greenland (Photos 1 and 2). Work concentrated on the life cycles of snow and glacier ice algae, and the impact of increased frequency and severity of rainfall and storms. Lab work has focussed on developing novel ways to characterising the adsorption properties of glacier ice algae for use in radiative transfer models.
Cultures have been established for algae living on the ice sheet surfaces in order to understand controls on the growth of snow and ice algae in their respective ice and and snow habitats, which has permitted work on the genomics of ice algae and in-depth understanding of their life cycles to be undertaken. A culture collection of other microbial members of the community, fungi and bacteria, is currently being established.
Deep Purple has been able to characterise the activity, nutrient requirements and genome of glacier ice algae, using novel single-cell techniques (secondary ion mass spectrometry (SIMS), combined scanning electron microscopy, and single cell sorting).
We designed, tested and validated new methods to collect, preserve, process and analyse the very low levels of organic carbon contents in the melted snow and ice by avoiding any use of plastics in the procedures.
A very pleasing aspect of these achievements has been the interdisciplinary, collaborative and synergistic way in which are groups have worked and cooperated. There is a strong sense of group identity and achievement, with a realisation that our collective creativity and output is much greater than the sum of the individual parts.
Cultures have been established for algae living on the ice sheet surfaces in order to understand controls on the growth of snow and ice algae in their respective ice and and snow habitats, which has permitted work on the genomics of ice algae and in-depth understanding of their life cycles to be undertaken. A culture collection of other microbial members of the community, fungi and bacteria, is currently being established.
Deep Purple has been able to characterise the activity, nutrient requirements and genome of glacier ice algae, using novel single-cell techniques (secondary ion mass spectrometry (SIMS), combined scanning electron microscopy, and single cell sorting).
We designed, tested and validated new methods to collect, preserve, process and analyse the very low levels of organic carbon contents in the melted snow and ice by avoiding any use of plastics in the procedures.
A very pleasing aspect of these achievements has been the interdisciplinary, collaborative and synergistic way in which are groups have worked and cooperated. There is a strong sense of group identity and achievement, with a realisation that our collective creativity and output is much greater than the sum of the individual parts.
We have produced the first harmonised satellite remote sensing data for albedo variations in the Dark Zone, from 1984 to 2020 (https://github.com/fsn1995/Remote-Sensing-of-Albedo). There has been widespread community uptake of the BIOSNICER GO radiative transfer model (https://github.com/jmcook1186/BioSNICAR_GO) the state of the science model for calculating the impact of both organic and inorganic particulates on ice melt. New methodology has been developed for measuring the adsorption capacity of glacier ice algal cells, providing new fundamental data for use in radiative transfer models.
We expect to have published the first full genome of the glacier algae and provide in-depth understanding of their characteristics and evolutionary trades that allow them to survive and thrive on ice surfaces. This will have a high impact in the subject area, considering that the glacier ice algae do not only inhabit the Greenland Ice Sheet, but glaciers worldwide.
The understanding of the nutrient requirements from the single cell work will also allow refinement of the culturing work that will allow for the next generation of laboratory experiments with glacier ice algae. This would include, for example, understanding of how ice algae interact with other members of the microbial community, mechanisms for production of pigment (that ultimately impact on albedo), and their adaptation mechanisms to freeze-thawing conditions.
We optimized our ability to characterize the structure of ice – algae - mineral rich layers in 3D by cryogenic cryo-computer tomography (cryo-µ-CT), using laboratory prepared synthetic cores (see Fig. 1). We initiated a new collaboration for cryo-µ-CT at the European Synchrotron Radiation Facility (ESRF) in Grenoble, where we carried out our first tests. Thereafter, we analysed our first real ice cores (Fig. 2). The initial data is very promising, but the voxel size achieved with the laboratory based µ-CT scanner is ~ 70 µm voxel and better resolution is needed. This can be achieved we have submitted a beamtime application for analyses of smaller sections of new real ice core samples to be collected in June 2022. Our goal is to achieve a resolution of ~ 2-3 µm, enabling us to distinguish the structure of ice, mineral grains and microbes based on differential densities (see Fig. 1).
We designed, built and iteratively tested a new sample holder and insertion mechanisms for the scanning electron microscope so that we can now image samples returned frozen from the field and evaluate how the microbes, minerals and ice crystals are distributed on the ice surface during melting (Fig. 3). First results are promising, and we aim to submit a patent for this device via the GFZ technology transfer office.
These achievements to date give us great confidence that we will fulfil the objectives we set ourselves above. Our talented team of early career researchers have the creativity, drive and ambition to make major impacts in their fields of endeavour.
We expect to have published the first full genome of the glacier algae and provide in-depth understanding of their characteristics and evolutionary trades that allow them to survive and thrive on ice surfaces. This will have a high impact in the subject area, considering that the glacier ice algae do not only inhabit the Greenland Ice Sheet, but glaciers worldwide.
The understanding of the nutrient requirements from the single cell work will also allow refinement of the culturing work that will allow for the next generation of laboratory experiments with glacier ice algae. This would include, for example, understanding of how ice algae interact with other members of the microbial community, mechanisms for production of pigment (that ultimately impact on albedo), and their adaptation mechanisms to freeze-thawing conditions.
We optimized our ability to characterize the structure of ice – algae - mineral rich layers in 3D by cryogenic cryo-computer tomography (cryo-µ-CT), using laboratory prepared synthetic cores (see Fig. 1). We initiated a new collaboration for cryo-µ-CT at the European Synchrotron Radiation Facility (ESRF) in Grenoble, where we carried out our first tests. Thereafter, we analysed our first real ice cores (Fig. 2). The initial data is very promising, but the voxel size achieved with the laboratory based µ-CT scanner is ~ 70 µm voxel and better resolution is needed. This can be achieved we have submitted a beamtime application for analyses of smaller sections of new real ice core samples to be collected in June 2022. Our goal is to achieve a resolution of ~ 2-3 µm, enabling us to distinguish the structure of ice, mineral grains and microbes based on differential densities (see Fig. 1).
We designed, built and iteratively tested a new sample holder and insertion mechanisms for the scanning electron microscope so that we can now image samples returned frozen from the field and evaluate how the microbes, minerals and ice crystals are distributed on the ice surface during melting (Fig. 3). First results are promising, and we aim to submit a patent for this device via the GFZ technology transfer office.
These achievements to date give us great confidence that we will fulfil the objectives we set ourselves above. Our talented team of early career researchers have the creativity, drive and ambition to make major impacts in their fields of endeavour.