A5064730267- Marine and coastal ecosystems
- Arctic and Antarctic ice dynamics
- Methane Hydrates and Related Phenomena
- Marine and coastal plant biology
- Oceanographic and Atmospheric Processes
- Coastal wetland ecosystem dynamics
- Polar Research and Ecology
- Marine Biology and Ecology Research
- Geology and Paleoclimatology Research
- Climate change and permafrost
- Cryospheric studies and observations
- Isotope Analysis in Ecology
- Marine and fisheries research
- Coastal and Marine Dynamics
- Geological formations and processes
- Atmospheric chemistry and aerosols
- Marine animal studies overview
- Indigenous Studies and Ecology
- Marine and environmental studies
- Microbial Community Ecology and Physiology
- Atmospheric and Environmental Gas Dynamics
- Coastal and Marine Management
- Integrated Water Resources Management
- Atmospheric Ozone and Climate
- Ocean Acidification Effects and Responses
Aarhus University
2015-2024
Marine Ecology Research Institute
2004-2011
DHI
1994
University of Copenhagen
1994
Abstract Microalgae colonizing the underside of sea ice in spring are a key component Arctic foodweb as they drive early primary production and transport carbon from atmosphere to ocean interior. Onset bloom algae is typically limited by availability light, current consensus that few tens‐of‐centimeters snow enough prevent sufficient solar radiation reach underneath ice. We challenge this consensus, investigated onset light requirement an bloom, importance optical properties for penetration....
Abstract. Aerosols, including biological aerosols, exert a significant influence on cloud formation, influencing the global climate through their effects radiative balance and precipitation. The Arctic region features persistent mixed-phase clouds, which are impacted by ice nucleating particles (INPs) that modulate phase transitions within affecting lifetime impacting region's climate. An increasing number of studies document soils harbor numerous biogenic INPs (bioINPs), but these have yet...
Our ability to assess biodiversity at relevant spatial and temporal scales for informing management is of increasing importance given this foundational identify mitigate the impacts global change. Collecting baseline information tracking ecological changes are particularly important areas experiencing rapid representing data gaps such as Arctic marine ecosystems. Environmental DNA has potential provide data. We extracted environmental from 90 surface sediment samples eukaryote diversity...
This is a study of the optical, physical and biological parameters sea ice water below it at stations (n=25) in central (>88°N) Eurasian sector Arctic Ocean during summer 2012 record low sea-ice minimum extent. Results show that photosynthetically active radiation (PAR) transmittance was (0.09) apparently related to high degree backscattering by air-filled brine channels left draining. The under-ice PAR also (8.4±4.5 SD µmol photons m−2 s−1) partly transmittance. There were no significant...
The Arctic is particularly vulnerable to climate change due a decrease in surface albedo caused by declining ice and snow cover. Aerosol-cloud feedbacks modulate warming, with clouds profoundly affecting the radiative balance of region through both cooling warming effects. concentration type ice-nucleating particles (INP) are key factors controlling cloud formation which directly influences properties lifetime. It has recently been proposed that microbially-produced INPs, come from marine...
Conserving additional energy from sunlight through bacteriochlorophyll (BChl)-based reaction center or proton-pumping rhodopsin is a highly successful life strategy in environmental bacteria. BChl and rhodopsin-based systems display contrasting characteristics the size of coding operon, cost biosynthesis, ease expression control, efficiency production. This raises an intriguing question whether single bacterium has evolved ability to perform these two types phototrophy complementarily...
Abstract The pelagic spring bloom is essential for Arctic marine food webs, and a crucial driver of carbon transport to the ocean depths. A critical challenge understanding its timing magnitude, predict changes in coming decades. Spring onset typically light-limited, beginning when irradiance increases or during ice breakup. Here we report an acute 9-day under-ice algal nutrient-poor, freshwater-influenced water under 1-m thick sea ice. It was dominated by mixotrophic brackish haptophytes (...
Abstract Blooms of pigmented algae darken the surface glaciers and ice sheets, thereby enhancing solar energy absorption amplifying snow melt. The impacts algal pigment community composition on darkening are still poorly understood. Here, we characterise glacier signatures bare surfaces study their role in photophysiology three Southeast Greenland. Purpurogallin astaxanthin esters dominated pools (mass ratios to chlorophyll a 32 56, respectively). Algal biomass pigments impacted chromophoric...
Sea-ice algae are a paramount feature of polar marine ecosystems and ice algal standing stocks characterized by high spatio-temporal variability. Traditional sampling techniques, e.g., coring, labor intensive, spatially limited invasive, thereby limiting our understanding biomass variability patterns. This has consequences for quantifying ice-associated distribution, primary production, detecting responses to changing environmental conditions. Close-range under-ice optical remote sensing...
The effects of temperature and light on both oxygen (O 2 ) production gross photosynthesis were resolved in a benthic microalgal community by combining two‐dimensional (2D) imaging O variable chlorophyll (Chl fluorescence. Images revealed photosynthetically active with spatial heterogeneity at the millimeter scale. Irradiance strongly increased pore‐water concentration, sediment net production, photosynthesis. latter was derived from measurements electron transfer rate (rETR) Photosystem II....
Formulae display:?Mathematical formulae have been encoded as MathML and are displayed in this HTML version using MathJax order to improve their display. Uncheck the box turn off. This feature requires Javascript. Click on a formula zoom.
Ice algae are key contributors to primary production and carbon fixation in the Arctic, light availability is assumed limit their growth productivity. We investigated photo-physiological responses sea ice increased irradiance during a spring bloom West Greenland. During 14 d field experiment, transmittance through was manipulated provide 3 under-ice regimes: low (0.04), medium (0.08), high (0.16) transmittances. Chlorophyll decreased with elevated relative control. Maximum dark-adapted...
Abstract Climate change is leading to harsher resuspension events in shallow coastal environments influencing benthic nutrient fluxes. However, we lack information on the quantitative connection between these fluxes and physical forces. Two identical experiments that were carried out both May August provided novel knowledge instantaneous effects of with known intensity dissolved inorganic (phosphate: DIP, ammonium: NH 4 + , nitrite+nitrate: NO x silicate, DSi) organic (phosphorus: DOP,...