31 research outputs found
Light in the Polar Night
How much light isa vailable for biological processes during Polar Night? This question appears simple enough. But the reality is that conventional light sen- sors for measuring visible light (~350 to ~700 nm) have not been sensitive enough to answer it. Beyond this technical challenge, âlightâ is a general term that must be qualified in terms of âlight climateâ before it has meaning for biological systems. In this chapter, we provide an answer to the question posed above and explore aspects of light climate during Polar Night with relevance to biology, specifically, how Polar Night is defined by solar elevation, atmospheric light in Polar Night and its propaga- tion underwater, bioluminescence in Polar Night and the concept of Polar Night as a deep-sea analogue, light pollution, and future perspectives. This chapter focuses on the quantity and quality of light present during Polar Night, while subsequent chapters in this volume focus on specific biological effects of this light for algae (Chap. âMarine Micro- and Macroalgae in the Polar Nightâ), zooplankton (Chaps.âZooplankton in the Polar Nightâ and âBiological Clocks and Rhythms in Polar Organismsâ), and fish (Chap. âFish Ecology in the Polar Nightâ)
Multiomics in the central Arctic Ocean for benchmarking biodiversity change.
Multiomics approaches need to be applied in the central Arctic Ocean to benchmark biodiversity change and to identify novel species and their genes. As part of MOSAiC, EcoOmics will therefore be essential for conservation and sustainable bioprospecting in one of the least explored ecosystems on Earth
Overview of the MOSAiC expedition: Physical oceanography
Arctic Ocean properties and processes are highly relevant to the regional and global coupled climate system,
yet still scarcely observed, especially in winter. Team OCEAN conducted a full year of physical oceanography
observations as part of the Multidisciplinary drifting Observatory for the Study of the Arctic Climate
(MOSAiC), a drift with the Arctic sea ice from October 2019 to September 2020. An international team
designed and implemented the program to characterize the Arctic Ocean system in unprecedented detail, from
the seafloor to the air-sea ice-ocean interface, from sub-mesoscales to pan-Arctic. The oceanographic
measurements were coordinated with the other teams to explore the ocean physics and linkages to the
climate and ecosystem. This paper introduces the major components of the physical oceanography program
and complements the other team overviews of the MOSAiC observational program. Team OCEANâs sampling
strategy was designed around hydrographic ship-, ice- and autonomous platform-based measurements to
improve the understanding of regional circulation and mixing processes. Measurements were carried out
both routinely, with a regular schedule, and in response to storms or opening leads. Here we present alongdrift time series of hydrographic properties, allowing insights into the seasonal and regional evolution of the
water column from winter in the Laptev Sea to early summer in Fram Strait: freshening of the surface,
deepening of the mixed layer, increase in temperature and salinity of the Atlantic Water. We also highlight
the presence of Canada Basin deep water intrusions and a surface meltwater layer in leads. MOSAiC most
likely was the most comprehensive program ever conducted over the ice-covered Arctic Ocean. While data
analysis and interpretation are ongoing, the acquired datasets will support a wide range of physical
oceanography and multi-disciplinary research. They will provide a significant foundation for assessing and
advancing modeling capabilities in the Arctic Ocean
Selective incorporation of dissolved organic matter (DOM) during sea ice formation
This study investigated the incorporation of DOM from seawater into . 1. The enrichment factors varied for different DOM fractions: EFs were the lowest for humic-like DOM (1.0-1.39) and highest for amino acid-like DOM (1.10-3.94). Enrichment was generally highest in frost flowers with there being less enrichment in bulk ice and brine. Size exclusion chromatography indicated that there was a shift towards smaller molecules in the molecular size distribution of DOM in the samples collected from newly formed ice compared to seawater. Spectral slope coefficients did not reveal any consistent differences between seawater and ice samples. We conclude that DOM is incorporated to sea ice relatively more than inorganic solutes during initial formation of sea ice and the degree of the enrichment depends on the chemical composition of DOM. © 2013 Elsevier B.V