Seasonal and interannual variability in temperature, chlorophyll and macronutrients in northern Marguerite Bay, Antarctica

Clarke, Andrew; Meredith, Michael P.; Wallace, Margaret I.; Brandon, Mark A.; Thomas, David N.

doi:10.1016/j.dsr2.2008.04.035

Cited by 172 publications

(286 citation statements)

References 54 publications

Supporting

Mentioning

264

Contrasting

Unclassified

Order By: Relevance

“…2c, d). The Joint Global Ocean Flux Study (JGOFS) Southern Ocean dataset (http://usjgofs.whoi.edu/ [45] show NH x(sw) at its most depleted during the months where the data of Savoie et al [31] demonstrates the greatest aerosol ammonium (December, January). This is consistent with our current understanding of the seasonal cycle of NH x(sw) in temperate and high-latitude oceans where the nutrient-limited months of high summer tend to efficiently re-use remineralised N, keeping concentrations low.…”

Section: Observed Coupling In Antarctic Datamentioning

confidence: 99%

Coupling between dimethylsulfide emissions and the ocean - atmosphere exchange of ammonia

Johnson

Bell

2008

Environ. Chem.

View full text Add to dashboard Cite

Environmental context. Dimethylsulfide (DMS) is recognised as a potentially significant climate-forcing gas, owing to its role in particle and cloud formation in the marine atmosphere, where it is the dominant source of acidity. Ammonia, the dominant naturally occurring base in the atmosphere, plays an important role in neutralising particles formed from DMS oxidation products and may even enhance the formation rate of new particles. A biogeochemical coupling has previously been proposed between DMS and ammonia fluxes from the ocean to the atmosphere, in the form of coproduction of the two gases in seawater. We revise this suggestion by introducing the concept of 'co-emission' of the gases, where DMS emission controls the rate of emission of ammonia from the ocean by acidifying the atmosphere. Abstract.A strong correlation between aerosol ammonium and non-sea salt sulfate is commonly observed in the remote marine boundary layer. It has been suggested that this relationship implies a biogeochemical linkage between the nitrogen (N) and sulfur (S) cycles at the cellular biochemical level in phytoplankton in the ocean, or a linkage in the atmosphere (see P. S. Liss and J. N. Galloway, Interactions of C, N, P and S biogeochemical cycles and global change (Springer, 1993), and P. K. Quinn et al. in J. Geophys. Res. -Atmos. 1990, 95). We argue that an oceanic linkage is unlikely and draw on mechanistic and observational evidence to make the argument that the atmospheric connection is based on simple physical chemistry. Drawing on an established analogous concept in terrestrial trace gas biogeochemistry, we propose that any emission of dimethylsulfide (DMS) from the ocean will indirectly influence the flux of NH 3 from the ocean, through the neutralisation of acidic DMS oxidation products and consequent lowering of the partial pressure of NH 3 in the atmosphere. We present a simple numerical model to investigate this hypothesised phenomenon, using a parameterisation of the rate and thermodynamics of gas-to-particle conversion of NH x and explicitly modelled oceanatmosphere NH 3 exchange. The model indicates that emission of acidic sulfur to the atmosphere (e.g. as a product of DMS oxidation) may enhance the marine emission of NH 3 . It also suggests that the ratio of ammonium to non-sea salt sulfate in the aerosol phase is strongly dependent on seawater pH, temperature and wind speed -factors that control the ocean-atmosphere ammonia flux. Therefore, it is not necessary to invoke a stoichiometric link between production rates of DMS and ammonia in the ocean to explain a given ammonium to non-sea salt sulfate ratio in the aerosol. We speculate that this mechanism, which can provide a continuous resupply of ammonia to the atmosphere, may be involved in a series of biogeochemical-climate feedbacks. His research interests are biogeochemical cycles taking place both within and between the ocean and its overlying atmosphere, with a focus on biogenic trace gases. He is currently working with Peter Liss as part of the Surfac...

show abstract

Section: Observed Coupling In Antarctic Datamentioning

confidence: 99%

Coupling between dimethylsulfide emissions and the ocean - atmosphere exchange of ammonia

Johnson

Bell

2008

Environ. Chem.

View full text Add to dashboard Cite

show abstract

“…Antarctic invertebrates such as the brachiopod Liothyrella uva were shown to have typically prolonged postprandial elevation of metabolic rates (Peck 1998(Peck , 2002Peck and Veal 2001) which points to a long duration of food utilization and may delay the onset of severe starvation in Antarctic invertebrates. In addition, Antarctic invertebrates typically have low metabolic rates as an adaptation to the extremely cold climate and intense seasonality with short summers and long periods of potential food shortage during winter (Clarke et al 2008;Peck and Conway 2000;Schloss et al 2012). The systemic occurrence of a starved phenotype may not be primarily apparent in the tissues tested in this experiment, especially the hemocytes, as one of the first biochemical symptoms would be mobilization of stored energy reserves, such as fat or protein.…”

Section: Cross Effects Of Starvation and Injury On Gene Expression Inmentioning

confidence: 99%

Age-dependent expression of stress and antimicrobial genes in the hemocytes and siphon tissue of the Antarctic bivalve, Laternula elliptica, exposed to injury and starvation

Husmann

Abele

Rosenstiel

et al. 2014

Cell Stress and Chaperones

View full text Add to dashboard Cite

Increasing temperatures and glacier melting at the Western Antarctic Peninsula (WAP) are causing rapid changes in shallow coastal and shelf systems. Climate change-related rising water temperatures, enhanced ice scouring, as well as coastal sediment runoff, in combination with changing feeding conditions and microbial community composition, will affect all elements of the nearshore benthic ecosystem, a major component of which is the Antarctic soft-shelled clam Laternula elliptica. A 454-based RNA sequencing was carried out on tissues and hemocytes of L. elliptica, resulting in 42,525 contigs, of which 48 % was assigned putative functions. Changes in the expression of putative stress response genes were then investigated in hemocytes and siphon tissue of young and old animals subjected to starvation and injury experiments in order to investigate their response to sedimentation (food dilution and starvation) and iceberg scouring (injury). Analysis of antioxidant defense (Le-SOD and Lecatalase), wound repair (Le-TIMP and Le-chitinase), and stress and immune response (Le-HSP70, Le-actin, and Letheromacin) genes revealed that most transcripts were more clearly affected by injury rather than starvation. The upregulation of these genes was particularly high in the hemocytes of young, fed individuals after acute injury. Only minor changes in expression were detected in young animals under the selected starvation conditions and in older individuals. The stress response of L. elliptica thus depends on the nature of the environmental cue and on age. This has consequences for future population predictions as the environmental changes at the WAP will differentially impact L. elliptica age classes and is bound to alter population structure.

show abstract

“…Near the West Antarctic Peninsula, currents impinging on the edge of the continental shelf upwell Circumpolar Deep Water (Clarke et al, 2008), supporting phytoplankton production in such areas as the Marguerite Trough (Prézelin et al, 2000;Dinniman et al, 2011). As in the Amundsen Sea, these waters often remain at sub-euphotic depths, but bathymetric features force Circumpolar Deep Water into the surface layer and stimulate diatom blooms (Prézelin et al, 2000).…”

Section: Impacts Of Advection On Primary Production In the Antarcticmentioning

confidence: 99%

“…At a smaller spatial scale, the advection of nutrient-rich Circumpolar Deep Water onto the shelves of the West Antarctic Peninsula helps maintain high levels of primary production and the resultant rich foraging grounds (Prézelin et al, 2000;Clarke et al, 2008;Marrari et al, 2011). Embayments along the west coast of the Peninsula, such as Marguerite Bay, are important foraging areas for whales, pinnipeds, and seabirds (e.g., Friedlaender et al, 2006Friedlaender et al, , 2011.…”

Section: Advection and The Location Of Seabird Colonies And Pinniped mentioning

confidence: 99%

“…Secondly, Circumpolar Deep Water, a relatively warm water mass located at a depth of $200-800 m, is advected onto the Antarctic continental shelf through localized upwelling (Clarke et al, 2008;Dinniman et al, 2011). Circumpolar Deep Water brings macro-and micronutrients onto the shelf where they may mix with surface waters and fuel phytoplankton growth.…”

Section: Impacts Of Advection On Primary Production In the Antarcticmentioning

confidence: 99%

See 1 more Smart Citation

Advection in polar and sub-polar environments: Impacts on high latitude marine ecosystems

Hunt

Drinkwater

Arrigo

et al. 2016

Progress in Oceanography

View full text Add to dashboard Cite

a b s t r a c tWe compare and contrast the ecological impacts of atmospheric and oceanic circulation patterns on polar and sub-polar marine ecosystems. Circulation patterns differ strikingly between the north and south. Meridional circulation in the north provides connections between the sub-Arctic and Arctic despite the presence of encircling continental landmasses, whereas annular circulation patterns in the south tend to isolate Antarctic surface waters from those in the north. These differences influence fundamental aspects of the polar ecosystems from the amount, thickness and duration of sea ice, to the types of organisms, and the ecology of zooplankton, fish, seabirds and marine mammals. Meridional flows in both the North Pacific and the North Atlantic oceans transport heat, nutrients, and plankton northward into the Chukchi Sea, the Barents Sea, and the seas off the west coast of Greenland. In the North Atlantic, the advected heat warms the waters of the southern Barents Sea and, with advected nutrients and plankton, supports immense biomasses of fish, seabirds and marine mammals. On the Pacific side of the Arctic, cold waters flowing northward across the northern Bering and Chukchi seas during winter and spring limit the ability of boreal fish species to take advantage of high seasonal production there. Southward flow of cold Arctic waters into sub-Arctic regions of the North Atlantic occurs mainly through Fram Strait with less through the Barents Sea and the Canadian Archipelago. In the Pacific, the transport of Arctic waters and plankton southward through Bering Strait is minimal.In the Southern Ocean, the Antarctic Circumpolar Current and its associated fronts are barriers to the southward dispersal of plankton and pelagic fishes from sub-Antarctic waters, with the consequent evolution of Antarctic zooplankton and fish species largely occurring in isolation from those to the north. The Antarctic Circumpolar Current also disperses biota throughout the Southern Ocean, and as a result, the biota tends to be similar within a given broad latitudinal band. South of the Southern Boundary of the ACC, there is a large-scale divergence that brings nutrient-rich water to the surface. This divergence, along with more localized upwelling regions and deep vertical convection in winter, generates elevated nutrient levels throughout the Antarctic at the end of austral winter. However, such elevated nutrient levels do not support elevated phytoplankton productivity through the entire Southern Ocean, as iron concentrations are rapidly removed to limiting levels by spring blooms in deep waters. However, coastal http://dx

show abstract

Seasonal and interannual variability in temperature, chlorophyll and macronutrients in northern Marguerite Bay, Antarctica

Cited by 172 publications

References 54 publications

Coupling between dimethylsulfide emissions and the ocean - atmosphere exchange of ammonia

Coupling between dimethylsulfide emissions and the ocean - atmosphere exchange of ammonia

Age-dependent expression of stress and antimicrobial genes in the hemocytes and siphon tissue of the Antarctic bivalve, Laternula elliptica, exposed to injury and starvation

Advection in polar and sub-polar environments: Impacts on high latitude marine ecosystems

Contact Info

Product

Resources

About