Effects of an <scp>A</scp>rctic under‐ice bloom on solar radiant heating of the water column

Taskjelle, Torbjørn; Granskog, Mats A.; Pavlov, Alexey K.; Hudson, Stephen R.; Hamre, Børge

doi:10.1002/2016jc012187

Cited by 25 publications

(5 citation statements)

References 34 publications

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“…This, in turn, may feedback on productivity through modulation of the light available to fuel primary production (Kauko et al, 2017). High standing stocks of organisms in the sea ice and water column also change the energy budget and heat uptake of these components as they increase the absorption of shortwave radiation, thereby affecting the freeze and melt cycles of their own habitat (Taskjelle et al, 2017;Zeebe et al, 1996). Also, sea ice microstructural properties relevant for gas exchange can be modified through ice algal production of extracellular polymeric substances (Krembs et al, 2011).…”

Section: 2mentioning

confidence: 99%

Overview of the MOSAiC expedition: Ecosystem

Fong,

Hoppe,

Team

et al. 2023

Preprint

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An international and interdisciplinary sea ice drift expedition, the ‘The Multidisciplinary drifting Observatory for the Study of Arctic Climate‘ (MOSAiC), was conducted from October 2019 to September 2020. The aim of MOSAiC was to study the interconnected physical, chemical and biological characteristics and processes from the atmosphere to the deep sea of the central Arctic system. The ecosystem team addressed current knowledge gaps and explored unknown biological properties over a complete seasonal cycle focusing on three major research areas: biodiversity, biogeochemical cycles and linkages to the environment. In addition to the coverage of core properties along a complete seasonal cycle, dedicated projects covered specific processes and habitats, or organisms on higher taxonomic or temporal resolution. A wide range of sampling approaches from sampling, sea ice coring, lead sampling to CTD rosette-based water sampling, plankton nets, ROVs and acoustic buoys was applied to address the science objectives. Further, a wide range of process-related measurements to address e.g. productivity patterns, seasonal migrations and diversity shifts were conducted both in situ and onboard RV Polarstern. This paper provides a detailed overview of the sampling approaches used to address the three main science objectives. It highlights the core sampling program and provides examples of two habitat- or process-specific projects. First results presented include high biological activities in winter time and the discovery of biological hotspots in underexplored habitats. The unique interconnectivity of the coordinated sampling efforts also revealed insights into cross-disciplinary interactions like the impact of biota on Arctic cloud formation. This overview further presents both lessons learned from conducting such a demanding field campaign and an outlook on spin-off projects to be conducted over the next years.

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Section: 2mentioning

confidence: 99%

Overview of the MOSAiC expedition: Ecosystem

Fong,

Hoppe,

Team

et al. 2023

Preprint

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“…Several excellent studies have modeled PAR transmittance through sea ice; however, they have only considered limited sea ice or snow conditions in a diffuse environment (e.g., Hill et al., 2018; Light et al., 2008, 2015; Pavlov et al., 2017; Perovich, 1990, 1991; Slagstad et al., 2011; Taskjelle et al., 2017; Verin et al., 2022; Zhang et al., 2010) or have applied a relatively simple exponential decay approach for light attenuation (e.g., Lim et al., 2022; Stroeve et al., 2021) that requires knowledge of the surface albedo to use. The study presented here uses a coupled atmosphere‐sea ice/snow radiative‐transfer model to calculate PAR transmittance for three different sea ice and snow scenarios: Winter, Spring, and Summer.…”

Section: Introductionmentioning

confidence: 99%

Calculations of Arctic Ice‐Ocean Interface Photosynthetically Active Radiation (PAR) Transmittance Values

Redmond Roche,

King

2024

Earth and Space Science

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Sea ice algae play an important role in the Arctic Ocean ecosystem, driving primary production in the spring and sequestering carbon to the deep ocean. Up to 45% of Arctic Ocean primary production occurs in ice‐covered areas; photosynthetically active radiation (PAR) is fundamental to driving this production. Sea ice, and particularly snow, strongly scatter and reflect light, reducing the amount of PAR transmitted to the ice‐ocean interface. The effect that varying thicknesses of sea ice (0.2–3.5 m) and snow (0.01–1 m) have on the value of PAR transmittance at the ice‐ocean interface are considered for a Winter, Spring, and Summer scenario. When characteristic Arctic Ocean conditions (2 m sea ice and ∼0.2 m snowpack) are modeled, there is roughly a two‐fold difference in PAR transmittance at the ice‐ocean interface between the Winter (0.003) and Spring (0.007) scenarios and an order of magnitude difference with the Summer scenario (0.04). The modeled values correlate within one standard deviation of measured values and show good agreement with extended pan‐Arctic Ocean field campaign measurements. The results also indicate that simple exponential decay methods may lead to inaccurate results, and radiative‐transfer modeling is required to accurately predict PAR transmittance at the ice‐ocean interface. Therefore, this study offers a novel mathematical technique to predict the value of PAR transmittance at the ice‐ocean interface. Coupled with year‐round near‐real‐time sea ice and snow thickness remote sensing data, this technique may improve understanding of primary production and carbon budgets in the changing Arctic Ocean.

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“…The influence of snow depth on light attenuation is far greater than sea ice alone. Snow-free ice can transmit up to 80% of incoming photosynthetically active radiation (PAR) [ 24 , 25 ], whereas a 10 cm layer of fresh snow can effectively block light, reducing visible light transmission to <5% of incoming PAR [ 26 ]. As such, if the sea ice covered areas of the Arctic were to experience higher snowfall with global warming, despite thinner ice, under-ice light levels could be significantly reduced, modifying the growth conditions for the microalgae below.…”

Section: Introductionmentioning

confidence: 99%

Biomolecular profiles of Arctic sea-ice diatoms highlight the role of under-ice light in cellular energy allocation

Duncan,

Nielsen,

Søreide

et al. 2024

ISME Communications

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Arctic sea-ice diatoms fuel polar marine food webs as they emerge from winter darkness into Spring. Through their photosynthetic activity they manufacture the nutrients and energy that underpin secondary production. Sea-ice diatom abundance and biomolecular composition vary in space and time. With climate change causing short-term extremes and long-term shifts in mean environmental conditions, understanding how and in what way diatoms adjust biomolecular stores with environmental perturbation is important to gain insight into future ecosystem energy production and nutrient transfer. Using synchrotron-based Fourier Transform Infra-Red microspectroscopy, we examined the biomolecular composition of five dominant sea-ice diatom taxa from landfast ice communities covering a range of under-ice light conditions during Spring, in Svalbard, Norway. In all five taxa we saw a doubling of lipid and fatty acid content when light transmitted to the ice-water interface was >5% but <15% (85–95% attenuation through snow and ice). We determined a threshold around 15% light transmittance after which biomolecular synthesis plateaued, likely due to photoinhibitory effects, except for Navicula spp, which continued to accumulate lipids. Increasing under-ice light availability led to increased energy allocation towards carbohydrates, but this was secondary to lipid synthesis, while protein content remained stable. It is predicted that under-ice light availability will change in the Arctic, increasing due to sea-ice thinning and potentially decreasing with higher snowfall. Our findings show that the nutritional content of sea-ice diatoms are taxon-specific and linked to these changes, highlighting potential implications for future energy and nutrient supply for the polar marine food web.

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Effects of an Arctic under‐ice bloom on solar radiant heating of the water column

Cited by 25 publications

References 34 publications

Overview of the MOSAiC expedition: Ecosystem

Overview of the MOSAiC expedition: Ecosystem

Calculations of Arctic Ice‐Ocean Interface Photosynthetically Active Radiation (PAR) Transmittance Values

Biomolecular profiles of Arctic sea-ice diatoms highlight the role of under-ice light in cellular energy allocation

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