scholarly journals Sea-ice impacts inter-annual variability in bloom phenology and carbon export

2021 ◽  
Author(s):  
Isabelle Sindiswa Giddy ◽  
Sarah-Anne Nicholson ◽  
Bastien Yves Queste ◽  
Sandy J. Thomalla ◽  
Sebastiaan Swart
Keyword(s):  
Sea Ice ◽  
Carbon Export ◽  
Annual Variability ◽  
Ice Impacts

Changes in phytoplankton concentration now drive increased Arctic Ocean primary production

Science ◽  
2020 ◽  
Vol 369 (6500) ◽  
pp. 198-202 ◽  
Author(s):  
K. M. Lewis ◽  
G. L. van Dijken ◽  
K. R. Arrigo
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Arctic Ocean ◽  
Open Water ◽  
Water Area ◽  
The Arctic ◽  
Carbon Export ◽  
Phytoplankton Primary Production ◽  
Open Water Area ◽  
The Arctic Ocean

Historically, sea ice loss in the Arctic Ocean has promoted increased phytoplankton primary production because of the greater open water area and a longer growing season. However, debate remains about whether primary production will continue to rise should sea ice decline further. Using an ocean color algorithm parameterized for the Arctic Ocean, we show that primary production increased by 57% between 1998 and 2018. Surprisingly, whereas increases were due to widespread sea ice loss during the first decade, the subsequent rise in primary production was driven primarily by increased phytoplankton biomass, which was likely sustained by an influx of new nutrients. This suggests a future Arctic Ocean that can support higher trophic-level production and additional carbon export.

Mechanism on how the spring Arctic sea ice impacts the East Asian summer monsoon

2013 ◽  
Vol 115 (1-2) ◽  
pp. 107-119 ◽  
Author(s):  
Dong Guo ◽  
Yongqi Gao ◽  
Ingo Bethke ◽  
Daoyi Gong ◽  
Ola M. Johannessen ◽  
...  
Keyword(s):  
Sea Ice ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Arctic Sea Ice ◽  
Arctic Sea ◽  
Asian Summer ◽  
Ice Impacts

Dynamics of antarctic penguin populations in relation to inter-annual variability in sea ice distribution

Polar Biology ◽  
1996 ◽  
Vol 16 (5) ◽  
pp. 321-330 ◽  
Author(s):  
P. N. Trathan ◽  
J. P. Croxall ◽  
E. J. Murphy
Keyword(s):  
Sea Ice ◽  
Annual Variability

Productivity and carbon export potential in the Weddell Sea, with a focus on the waters near Larsen C Ice Shelf

2020 ◽  
Author(s):  
Raquel Flynn ◽  
Jessica Burger ◽  
Shantelle Smith ◽  
Kurt Spence ◽  
Thomas Bornman ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Phytoplankton Community ◽  
Late Summer ◽  
Weddell Sea ◽  
Global Ocean ◽  
Ice Shelf ◽  
Carbon Export ◽  
Study Region ◽  
Ice Shelves

<p>Net primary production (NPP) is indicative of the energy available to an ecosystem, which is central to ecological functioning and biological carbon cycling. The Southern Ocean’s Weddell Sea (WS) represents a point of origin where water masses form and exchange with the atmosphere, thereby setting the physical and chemical conditions of much of the global ocean. The WS is particularly understudied near Larsen C Ice Shelf (LCIS) where harsh sea-ice conditions persist year-round. We measured size-fractionated rates of NPP, nitrogen (N; as nitrate, ammonium, and urea) uptake, and nitrification, and characterized the phytoplankton community at 19 stations in summer 2018/2019, mainly near LCIS, with a few stations in the open Weddell Gyre (WG) and at Fimbul Ice Shelf (FIS). Throughout the study region, NPP and N uptake were dominated by nanophytoplankton (3-20 μm), with microphytoplankton (>20 μm) becoming more abundant later in the season, particularly at FIS. Here, we observed high phytoplankton biomass and diversity, and the community was dominated by diatoms known to enhance carbon export (e.g., <em>Thalassiosira spp</em>.). At LCIS, by contrast, the community comprised mainly <em>Phaeocystis Antarctica</em>. In the open WG, a population of small and weakly-silicified diatoms of the genus <em>Corethron</em> dominated the phytoplankton community. Here, euphotic zone-integrated uptake rates were similar to those at LCIS even though the depth-specific rates were lower. Mixed-layer nitrification was below detection at all stations such that nitrate uptake can be used as a proxy for carbon export potential <em>sensu</em> the new production paradigm – this was highest near FIS in late summer. Our observations can be explained by melting sea ice near the ice shelves that supplies iron and enhances water column stratification, thus alleviating iron and/or light limitation of phytoplankton and allowing them to consume the abundant surface macronutrients. That the sea ice melted completely at FIS but not LCIS may explain why late-summer productivity and carbon export potential were highest near FIS, more than double the rates measured in early summer and near LCIS. The early-to-late summer progression near the ice shelves contrasts that of the open Southern Ocean where iron is depleted by late summer, driving a shift towards smaller phytoplankton that facilitate less carbon export.</p>

scholarly journals Sea ice as a source of sea salt aerosol to Greenland ice cores: a model-based study

2017 ◽  
Vol 17 (15) ◽  
pp. 9417-9433 ◽  
Author(s):  
Rachael H. Rhodes ◽  
Xin Yang ◽  
Eric W. Wolff ◽  
Joseph R. McConnell ◽  
Markus M. Frey
Keyword(s):  
Sea Ice ◽  
Atmospheric Chemistry ◽  
Transport Model ◽  
Ice Core ◽  
Ice Cores ◽  
Open Ocean ◽  
Sea Salt ◽  
The Arctic ◽  
Sea Salt Aerosol ◽  
Annual Variability

Abstract. Growing evidence suggests that the sea ice surface is an important source of sea salt aerosol and this has significant implications for polar climate and atmospheric chemistry. It also suggests the potential to use ice core sea salt records as proxies for past sea ice extent. To explore this possibility in the Arctic region, we use a chemical transport model to track the emission, transport, and deposition of sea salt from both the open ocean and the sea ice, allowing us to assess the relative importance of each. Our results confirm the importance of sea ice sea salt (SISS) to the winter Arctic aerosol burden. For the first time, we explicitly simulate the sea salt concentrations of Greenland snow, achieving values within a factor of two of Greenland ice core records. Our simulations suggest that SISS contributes to the winter maxima in sea salt characteristic of ice cores across Greenland. However, a north–south gradient in the contribution of SISS relative to open-ocean sea salt (OOSS) exists across Greenland, with 50 % of winter sea salt being SISS at northern sites such as NEEM (77° N), while only 10 % of winter sea salt is SISS at southern locations such as ACT10C (66° N). Our model shows some skill at reproducing the inter-annual variability in sea salt concentrations for 1991–1999, particularly at Summit where up to 62 % of the variability is explained. Future work will involve constraining what is driving this inter-annual variability and operating the model under different palaeoclimatic conditions.

scholarly journals Sea ice as a source of sea salt aerosol to Greenland ice cores: a model-based study

2017 ◽  
Author(s):  
Rachael H. Rhodes ◽  
Xin Yang ◽  
Eric W. Wolff ◽  
Joseph R. McConnell ◽  
Markus M. Frey
Keyword(s):  
Sea Ice ◽  
Atmospheric Chemistry ◽  
Transport Model ◽  
Ice Core ◽  
Ice Cores ◽  
Open Ocean ◽  
Sea Salt ◽  
The Arctic ◽  
Sea Salt Aerosol ◽  
Annual Variability

Abstract. Growing evidence suggests that the sea ice surface is an important source of sea salt aerosol and this has significant implications for polar climate and atmospheric chemistry. It also offers the opportunity to use ice core sea salt records as proxies for past sea ice extent. To explore this possibility in the Arctic region, we use a chemical transport model to track the emission, transport and deposition of sea salt from both the open ocean and the sea ice, allowing us to assess the relative importance of each. Our results confirm the importance of sea ice sea salt (SISS) to the winter Arctic aerosol burden. For the first time, we explicitly simulate the sea salt concentrations of Greenland snow and find they match high resolution Greenland ice core records to within a factor of two. Our simulations suggest that SISS contributes to the winter maxima in sea salt characteristic of ice cores across Greenland. A north-south gradient in the contribution of SISS relative to open ocean sea salt (OOSS) exists across Greenland, with 50 % of sea salt being SISS at northern sites such as NEEM, while only 10 % of sea salt is SISS at southern locations such as ACT10C. Our model shows some skill at reproducing the inter-annual variability in sea salt concentrations for 1991–1999 AD, particularly at Summit where up to 62 % of the variability is explained. Future work will involve constraining what is driving this inter-annual variability and operating the model under different paleoclimatic conditions.

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