Marcel Nicolaus
A5083908471- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Calibration and Measurement Techniques
- Infrared Target Detection Methodologies
- Atmospheric and Environmental Gas Dynamics
- Marine and Coastal Research
- Atmospheric Ozone and Climate
- Arctic and Russian Policy Studies
- Food Industry and Aquatic Biology
- Spacecraft and Cryogenic Technologies
- Marine animal studies overview
- Geophysics and Gravity Measurements
- Ocean Acidification Effects and Responses
- Winter Sports Injuries and Performance
- Oceanographic and Atmospheric Processes
- Ionosphere and magnetosphere dynamics
- Marine and environmental studies
- Solar Radiation and Photovoltaics
- Solar and Space Plasma Dynamics
- Geological Studies and Exploration
- Icing and De-icing Technologies
- Cephalopods and Marine Biology
- Marine Biology and Ecology Research
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2015-2024
Naval Postgraduate School
2024
Moss Landing Marine Laboratories
2024
University of Plymouth
2024
Universität Hamburg
2020-2022
British Antarctic Survey
2020
Ocean Atmosphere Systems (Germany)
2020
University College London
2020
University of Manitoba
2020
Max Planck Society
2013-2015
Diatom Fall 2012 saw the greatest Arctic ice minimum ever recorded. This allowed unprecedented access for research vessels deep into Ocean to make high-latitude observations of melt and associated phenomena. From RV Polarstern between 84° 89° North, Boetius et al. (p. 1430 , published online 14 February; see cover) observed large-scale algal aggregates diatom Melosira arctica hanging beneath multiyear seasonal across a wide range latitudes. The strands algae were readily dislodged formed on...
Abstract Clouds play an important role in Arctic amplification. This term represents the recently observed enhanced warming of relative to global increase near-surface air temperature. However, there are still knowledge gaps regarding interplay between clouds and aerosol particles, surface properties, as well turbulent radiative fluxes that inhibit accurate model simulations climate system. In attempt resolve this so-called cloud puzzle, two comprehensive closely coordinated field studies...
With the Arctic rapidly changing, needs to observe, understand, and model changes are essential. To support these needs, an annual cycle of observations atmospheric properties, processes, interactions were made while drifting with sea ice across central during Multidisciplinary Observatory for Study Climate (MOSAiC) expedition from October 2019 September 2020. An international team designed implemented comprehensive program document characterize all aspects system in unprecedented detail,...
Arctic sea ice has declined and become thinner younger (more seasonal) during the last decade. One consequence of this is that surface energy budget Ocean changing. While role albedo been studied intensively, it still widely unknown how much light penetrates through into upper ocean, affecting sea‐ice mass balance, ecosystems, geochemical processes. Here we present first large‐scale under‐ice measurements, operating spectral radiometers on a remotely operated vehicle (ROV) under in summer....
Abstract The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to thinner and largely seasonal first-year with significant consequences for primary production. One critical challenge understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea during summer, indicating that satellite-based annual production estimates may be significantly underestimated. Here we present unique...
Year-round observations of the physical snow and ice properties processes that govern pack evolution its interaction with atmosphere ocean were conducted during Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) expedition research vessel Polarstern in Ocean from October 2019 to September 2020. This work was embedded into interdisciplinary design 5 MOSAiC teams, studying atmosphere, sea ice, ocean, ecosystem, biogeochemical processes. The overall aim characterize cover...
Abstract Near‐surface air temperatures close to 0°C were observed in situ over sea ice the central Arctic during last three winter seasons. Here we use (December–March) temperature observations, such as those from Soviet North Pole drifting stations and ocean buoys, determine how common warming events are. Observations of exist most Basin. Temperatures exceeding −5°C >30% winters 1954 2010 by or buoys. Using ERA‐Interim record (1979–2016), show that (NP) region typically experiences 10...
Arctic Ocean properties and processes are highly relevant to the regional global coupled climate system, yet still scarcely observed, especially in winter. Team OCEAN conducted a full year of physical oceanography observations as part Multidisciplinary drifting Observatory for Study Climate (MOSAiC), drift with sea ice from October 2019 September 2020. An international team designed implemented program characterize system unprecedented detail, seafloor air-sea ice-ocean interface,...
Abstract Sea ice is an important transport vehicle for gaseous, dissolved and particulate matter in the Arctic Ocean. Due to recently observed acceleration sea drift, it has been assumed that more advected by Transpolar Drift from shallow shelf waters central Ocean beyond. However, this study provides first evidence intensified melt marginal zones of interrupts transarctic conveyor belt led a reduction survival rates exported Siberian shelves (−15% per decade). As consequence, less formed...
Sea ice growth and decay are critical processes in the Arctic climate system, but comprehensive observations very sparse. We analyzed data from 23 sea mass balance buoys (IMBs) deployed during Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition 2019–2020 to investigate seasonality timing thermodynamic Transpolar Drift. The reveal four stages season: (I) onset basal freezing, mid-October November; (II) rapid growth, December–March; (III) slow April–May; (IV)...
Sea ice thickness is a key parameter in the polar climate and ecosystem. Thermodynamic dynamic processes alter sea thickness. The Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition provided unique opportunity to study seasonal changes same ice. We analyzed 11 large-scale (∼50 km) airborne electromagnetic surface roughness surveys from October 2019 September 2020. Data mass balance position buoys additional information. found that thermodynamic growth decay...
Abstract. The ice-covered central Arctic Ocean is characterized by low primary productivity due to light and nutrient limitations. recent reduction in ice cover has the potential substantially increase phytoplankton production, but little yet known about fate of ice-associated production supply with increasing warming. This study presents results from collected during summer 2012, when sea-ice extent reached its lowest ever recorded since onset satellite observations. Net (NPP) was measured...
Abstract Arctic sea ice has displayed significant thinning as well an increase in drift speed recent years. Taken together this suggests associated rise deformation rate. A winter and spring expedition to the covered region north of Svalbard–the Norwegian young ICE2015 (N‐ICE2015)—gave opportunity deploy extensive buoy arrays monitor first‐year second‐year now common majority Basin. During 5 month long expedition, cover underwent several strong events, including a powerful storm early...
Abstract The Arctic sea ice cover is rapidly shrinking, but a direct, longer‐term assessment of the thinning remains challenging. A new time series constructed from in situ measurements thickness at end melt season Fram Strait shows by over 50% during 2003–2012. modal and mean along 79°N decreased rate 0.3 0.2 m yr −1 , respectively, with long‐term averages 2.5 3 m. Airborne observations reveal an east‐west gradient across strait spring not summer due to advection more different source...
Abstract Methylmercury (MeHg) is a neurotoxic compound that threatens wildlife and human health across the Arctic region. Though much known about source dynamics of its inorganic mercury (Hg) precursor, exact origin high MeHg concentrations in biota remains uncertain. coastal sediments, marine waters surface snow are sites for production. Observations on Hg dynamics, however, have been restricted to Canadian Archipelago Beaufort Sea (<79°N). Here we present first central Ocean (79–90°N)...
Abstract. In September 2019, the research icebreaker Polarstern started largest multidisciplinary Arctic expedition to date, MOSAiC (Multidisciplinary drifting Observatory for Study of Climate) drift experiment. Being moored an ice floe a whole year, thus including winter season, declared goal is better understand and quantify relevant processes within atmosphere–ice–ocean system that impact sea mass energy budget, ultimately leading much improved climate models. Satellite observations,...
During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm diameter) had a mucous consistency were dominated by typical ice-associated pennate diatoms embedded within matrix. Aggregates maintained buoyancy accumulated just above strong pycnocline that separated meltwater seawater layers. We able, for first time, obtain quantitative...
Water vapor transport has been highlighted as a critical process in Arctic snowpacks, shaping the snow cover structure terms of density, thermal conductivity, and temperature profile among others. Here, we present an attempt to describe thermally-induced vertical diffusion water its effects snowpack using SNOWPACK model. Convection, that may also constitute significant part transport, is not addressed. Assuming saturated conditions at upper boundary initial condition, flux between layers...
Snow depth on sea ice is an essential state variable of the polar climate system and yet one least known most difficult to characterize parameters Arctic Antarctic systems. Here, we present a new type autonomous platform measure snow depth, air temperature, barometric pressure drifting ice. “Snow Buoys” are designed withstand harshest environmental conditions deliver high consistent data quality with minimal impact surface. Our current dataset consists 79 time series (47 Arctic, 32...
Abstract. Data from the Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition allowed us to investigate temporal dynamics snowfall, snow accumulation and erosion in great detail almost whole season (November 2019 May 2020). We computed cumulative water equivalent (SWE) over sea ice based on depth density retrievals a SnowMicroPen approximately weekly measured depths along fixed transect paths. used derived SWE cover compare with precipitation sensors...
Abstract Melt ponds forming on Arctic sea ice in summer significantly reduce the surface albedo and impact heat mass balance of ice. Therefore, their areal coverage, which can undergo rapid change, is crucial to monitor. We present a revised method extract melt pond fraction (MPF) from Sentinel‐2 satellite imagery, evaluated by MPF products higher‐resolution helicopter‐borne imagery. The analysis evolution during MOSAiC campaign 2020, shows split Central Observatory (CO) into level highly...
The rapid melt of snow and sea ice during the Arctic summer provides a significant source low-salinity meltwater to surface ocean on local scale. accumulation this on, under, around floes can result in relatively thin layers upper ocean. Due small-scale nature these upper-ocean features, typically order 1 m thick or less, they are rarely detected by standard methods, but nevertheless pervasive critically important summer. Observations Multidisciplinary drifting Observatory for Study Climate...
Central Arctic properties and processes are important to the regional global coupled climate system. The Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) Distributed Network (DN) autonomous ice-tethered systems aimed bridge gaps in our understanding temporal spatial scales, particular with respect resolution Earth system models. By characterizing variability around local measurements made at a Observatory, DN covers both interactions involving ocean-ice-atmosphere...