Influence of Sea Ice Crack Formation on the Spatial Distribution of Nutrients and Microalgae in Flooded Antarctic Multiyear Ice

Nomura, Daïki; Aoki, Shigeru; Simizu, Daisuke; Iida, Takuya

doi:10.1002/2017jc012941

Cited by 13 publications

(24 citation statements)

References 47 publications

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“…The development of a diatom bloom under sea-ice conditions is consistent with previous investigations that have reported large under-ice phytoplankton blooms in polar environments (e.g. Arrigo et al, 2012;Lowry et al, 2018;Nomura et al, 2018) The high contribution of the sea-ice affiliated species F. cylindrus and F. curta (13% and 9%, respectively) during the November supports the idea of an early initiation of the phytoplankton bloom triggered by the receding sea ice as previously suggested by Pilskaln et al (2004).…”

Section: Diatom Species Succession At 1400 M At Pzb-1supporting

confidence: 91%

Diatom species fluxes in the seasonally ice-covered Antarctic Zone: New data from offshore Prydz Bay and comparison with other regions from the eastern Antarctic and western Pacific sectors of the Southern Ocean

Rigual-Hernández

Pilskaln

Cortina

et al. 2019

Deep Sea Research Part II: Topical Studies in Oceanography

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The Antarctic Zone, the southernmost belt of the Antarctic Circumpolar Current, plays an important role in the control of atmospheric carbon dioxide concentrations. In the last decade, a number of studies have highlighted the importance of diatom assemblage composition in influencing the magnitude of the organic carbon and biogenic silica fluxes exported out of the mixed layer in Southern Ocean ecosystems. Here we investigate the relationship between the makeup of the diatom assemblage, organic carbon and biogenic silica export and several significant environmental parameters using sediment trap records deployed in different sectors of the Antarctic Zone. The study is divided in two parts. We first present unpublished diatom species flux data collected by a sediment trap in the offshore waters of Prydz Bay (Station PZB-1) over a year. The results of this study revealed a major export peak of diatom valves in Austral summer and two small unexpected secondary flux pulses during full winter conditions. The summer diatom sinking assemblages were largely composed of small and rapidly dividing species such as Fragilariopsis cylindrus, Fragilariopsis curta and Pseudo-nitzschia lineola, while winter assemblages were dominated by Fragilariopsis kerguelensis most reflecting its persistent strategy and selective preservation. In the second part of the study, we compare the annual diatom assemblage composition and biogeochemical fluxes of Station PZB-1 with flux data documented in previous sediment trap studies conducted in other sectors of the Antarctic Zone in order to investigate how diatom floristics influence the composition and magnitude of particle fluxes in the Antarctic Zone. The lack of correlation between the annual diatom valve, organic carbon and biogenic silica fluxes across stations indicates that other factors aside from diatom abundance play a major role in the carbon and silica export in AZ. Among these factors, the composition of the diatom assemblage appears to be critical, as suggested by the strong and significant correlation between Bio-SiO2 and the valve fluxes of F. kerguelensis alone, that this species is the main Bio-SiO2 vector from the surface layer to the deep ocean in the AZ waters, regardless of its relative abundance. Lastly, the good correlation between the annual fluxes of the group of small Fragilariopsis species with satellite-derived chlorophyll-a concentration estimates over the study stations, suggest that high abundances of these species in the Southern Ocean paleorecords could be used as a proxy of high algal biomass accumulation.

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Section: Diatom Species Succession At 1400 M At Pzb-1supporting

confidence: 91%

Diatom species fluxes in the seasonally ice-covered Antarctic Zone: New data from offshore Prydz Bay and comparison with other regions from the eastern Antarctic and western Pacific sectors of the Southern Ocean

Rigual-Hernández

Pilskaln

Cortina

et al. 2019

Deep Sea Research Part II: Topical Studies in Oceanography

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“…In this study, we used the following endmember values: sea-ice meltwater ( S sim = 0.50, δ 18 O sim = −5.0‰, e.g., ref. 50 ), meteoric water ( S met = 0.0, δ 18 O met = −40‰, e.g., ref. 35 ), and mCDW ( S mCDW = 34.65, δ 18 O mCDW = −0.078‰) observed at the mouth of LHB (Sta.G3).…”

Section: Methodsmentioning

confidence: 99%

Strong ice-ocean interaction beneath Shirase Glacier Tongue in East Antarctica

et al. 2020

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Mass loss from the Antarctic ice sheet, Earth’s largest freshwater reservoir, results directly in global sea-level rise and Southern Ocean freshening. Observational and modeling studies have demonstrated that ice shelf basal melting, resulting from the inflow of warm water onto the Antarctic continental shelf, plays a key role in the ice sheet’s mass balance. In recent decades, warm ocean-cryosphere interaction in the Amundsen and Bellingshausen seas has received a great deal of attention. However, except for Totten Ice Shelf, East Antarctic ice shelves typically have cold ice cavities with low basal melt rates. Here we present direct observational evidence of high basal melt rates (7–16 m yr −1 ) beneath an East Antarctic ice shelf, Shirase Glacier Tongue, driven by southward-flowing warm water guided by a deep continuous trough extending to the continental slope. The strength of the alongshore wind controls the thickness of the inflowing warm water layer and the rate of basal melting.

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“…It has been argued that leads and cracks within sea ice are hot spots for gas exchange between the air and surface water (Else et al, 2013;Loose et al, 2009Loose et al, , 2016Steiner et al, 2013;Zemmelink et al, 2008). In LHB, land-fast ice is sometimes broken up (Aoki, 2017;Ushio, 2006), crack formation frequently occurs (Nomura, Aoki, et al, 2018). Because it is difficult to estimate the area of the small leads and cracks from the satellite when small leads and cracks is <20 m width scale, the sea−air CO 2 flux at the small leads and cracks was estimated on the assumption that the area percentage of unresolved small leads and cracks were 1%-2% within the sea ice (Steiner et al, 2013).…”

Section: The Effect Of the Basal Melting Of Sgt On The Co 2 System In Lhbmentioning

confidence: 99%

The Effect of Basal Melting of the Shirase Glacier Tongue on the CO₂ System in Lützow‐Holm Bay, East Antarctica

et al. 2021

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The ocean absorbs more than 25% of anthropogenic carbon dioxide (CO 2 ) emitted by human activities (Friedlingstein et al., 2019;Le Quéré et al., 2016). The Southern Ocean accounts for 40% of the anthropogenic CO 2 absorbed by the ocean, and it plays an important role in the global carbon cycle as a sink of anthropogenic CO 2 (Gruber et al., 2019;Sabine et al., 2004;Takahashi et al., 2009). However, the estimation of air-sea CO 2 exchange is limited to the open water area of the Southern Ocean. The air-sea CO 2 flux on the Antarctic continental shelves, which are covered with sea ice seasonally or throughout the year, are uncertain because direct observations have been limited (Lenton et al., 2013). In the ocean, CO 2 exists in three different inorganic forms: as aqueous CO 2 (CO 2 (aq)), as HCO 3 − , and as CO 3 2−. The sum of the three different inorganic forms is called the dissolved inorganic carbon (DIC) (Zeebe & Wolf-Gladrow, 2001). The processes that affect the DIC in the polar oceans include: (1) photosynthesis and respiration by biological activity, (2) mixing of water masses (dilution effect by melting of shelf ice and sea ice), (3) precipitation and dissolution of calcium carbonate (CaCO 3 • 6H 2 O), and (4) air-sea CO 2 exchange. In the Antarctic coastal zone, (1) and ( 2) are considered to be especially important processes (e.g.,

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Influence of Sea Ice Crack Formation on the Spatial Distribution of Nutrients and Microalgae in Flooded Antarctic Multiyear Ice

Cited by 13 publications

References 47 publications

Diatom species fluxes in the seasonally ice-covered Antarctic Zone: New data from offshore Prydz Bay and comparison with other regions from the eastern Antarctic and western Pacific sectors of the Southern Ocean

Diatom species fluxes in the seasonally ice-covered Antarctic Zone: New data from offshore Prydz Bay and comparison with other regions from the eastern Antarctic and western Pacific sectors of the Southern Ocean

Strong ice-ocean interaction beneath Shirase Glacier Tongue in East Antarctica

The Effect of Basal Melting of the Shirase Glacier Tongue on the CO₂ System in Lützow‐Holm Bay, East Antarctica

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Influence of Sea Ice Crack Formation on the Spatial Distribution of Nutrients and Microalgae in Flooded Antarctic Multiyear Ice

Cited by 13 publications

References 47 publications

Diatom species fluxes in the seasonally ice-covered Antarctic Zone: New data from offshore Prydz Bay and comparison with other regions from the eastern Antarctic and western Pacific sectors of the Southern Ocean

Diatom species fluxes in the seasonally ice-covered Antarctic Zone: New data from offshore Prydz Bay and comparison with other regions from the eastern Antarctic and western Pacific sectors of the Southern Ocean

Strong ice-ocean interaction beneath Shirase Glacier Tongue in East Antarctica

The Effect of Basal Melting of the Shirase Glacier Tongue on the CO2 System in Lützow‐Holm Bay, East Antarctica

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The Effect of Basal Melting of the Shirase Glacier Tongue on the CO₂ System in Lützow‐Holm Bay, East Antarctica