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Articles 1 - 12 of 12
Full-Text Articles in Physical Sciences and Mathematics
Sensitivity Of The Relationship Between Antarctic Ice Shelves And Iron Supply To Projected Changes In The Atmospheric Forcing, Michael S. Dinniman, Pierre St-Laurent, Kevin R. Arrigo, Eileen E. Hofmann, Gert L. Van Dijken
Sensitivity Of The Relationship Between Antarctic Ice Shelves And Iron Supply To Projected Changes In The Atmospheric Forcing, Michael S. Dinniman, Pierre St-Laurent, Kevin R. Arrigo, Eileen E. Hofmann, Gert L. Van Dijken
CCPO Publications
Upward advection or mixing of iron-rich deep waters due to circulation changes driven by the rate of basal ice shelf melt was shown to be a primary control on chlorophyll a production in coastal polynyas over the Antarctic continental shelf. Here, the effects of atmospheric changes projected in 2100 on this relationship were examined with a 5-km resolution ocean/sea ice/ice shelf model of the Southern Ocean with different simulated dissolved iron sources and idealized biological uptake. The atmospheric changes are added as idealized increments to the forcing. Inclusion of a poleward shift and strengthening of the winds, increased precipitation, and …
The Response Of Sea Ice And High-Salinity Shelf Water In The Ross Ice Shelf Polynya To Cyclonic Atmosphere Circulations, Xiaoqiao Wang, Zhaoru Zhang, Michael S. Dinniman, Petteri Uotila, Xichen Li, Meng Zhou
The Response Of Sea Ice And High-Salinity Shelf Water In The Ross Ice Shelf Polynya To Cyclonic Atmosphere Circulations, Xiaoqiao Wang, Zhaoru Zhang, Michael S. Dinniman, Petteri Uotila, Xichen Li, Meng Zhou
CCPO Publications
Coastal polynyas in the Ross Sea are important source regions of high-salinity shelf water (HSSW) – the precursor of Antarctic Bottom Water that supplies the lower limb of the thermohaline circulation. Here, the response of sea ice production and HSSW formation to synoptic-scale and mesoscale cyclones was investigated for the Ross Ice Shelf Polynya (RISP) using a coupled ocean–sea ice–ice shelf model targeted on the Ross Sea. When synoptic-scale cyclones prevailed over RISP, sea ice production (SIP) increased rapidly by 20 %–30 % over the entire RISP. During the passage of mesoscale cyclones, SIP increased by about 2 times over …
Seasonal Variations In Circumpolar Deep Water Intrusions Into The Ross Sea Continental Shelf, Yufei Wang, Meng Zhou, Zhaoru Zhang, Michael S. Dinniman
Seasonal Variations In Circumpolar Deep Water Intrusions Into The Ross Sea Continental Shelf, Yufei Wang, Meng Zhou, Zhaoru Zhang, Michael S. Dinniman
CCPO Publications
Intrusions of the warm and nutrient-rich Circumpolar Deep Water (CDW) across the Ross Sea shelf break play an important role in providing heat for ice shelf basal melting and setting the physical environment for biochemical processes. Several mechanisms driving CDW intrusions into the Ross Sea were proposed such as mesoscale eddies, tidal rectification, and interactions between Antarctic Slope Current (ASC) and topographic features. The seasonal variations in the poleward transport of CDW are investigated using ERA-Interim wind data and a Ross Sea circulation model based on the Regional Ocean Modeling System (ROMS) between September 1999 and September 2014. The analyses …
Constraining An Ocean Model Under Getz Ice Shelf, Antarctica, Using A Gravity‐Derived Bathymetry, Romain Millan, Pierre St-Laurent, Eric Rignot, Mathieu Morlighem, Jeremie Mouginot, Bernd Scheuchl
Constraining An Ocean Model Under Getz Ice Shelf, Antarctica, Using A Gravity‐Derived Bathymetry, Romain Millan, Pierre St-Laurent, Eric Rignot, Mathieu Morlighem, Jeremie Mouginot, Bernd Scheuchl
CCPO Publications
Getz Ice Shelf, the largest producer of ice shelf meltwater in Antarctica, buttresses glaciers that hold enough ice to raise sea level by 22 cm. We present a new bathymetry of its sub‐ice shelf cavity using a three‐dimensional inversion of airborne gravity data constrained by multibeam bathymetry at sea and a reconstruction of the bedrock from mass conservation on land. The new bathymetry is deeper than previously estimated with differences exceeding 500 m in a number of regions. When incorporated into an ocean model, it yields a better description of the spatial distribution of ice shelf melt, specifically along glacier …
Modeling The Seasonal Cycle Of Iron And Carbon Fluxes In The Amundsen Sea Polynya, Antarctica, P. St-Laurent, P. L. Yager, R. M. Sherrell, H. Oliver, M. S. Dinniman, S. E. Stammerjohn
Modeling The Seasonal Cycle Of Iron And Carbon Fluxes In The Amundsen Sea Polynya, Antarctica, P. St-Laurent, P. L. Yager, R. M. Sherrell, H. Oliver, M. S. Dinniman, S. E. Stammerjohn
CCPO Publications
The Amundsen Sea Polynya (ASP) is distinguished by having the highest net primary production per unit area in the coastal Antarctic. Recent studies have related this high productivity to the presence of fast-melting ice shelves, but the mechanisms involved are not well understood. In this study we describe the first numerical model of the ASP to represent explicitly the ocean-ice interactions, nitrogen and iron cycles, and the coastal circulation at high resolution. The study focuses on the seasonal cycle of iron and carbon, and the results are broadly consistent with field observations collected during the summer of 2010–2011. The simulated …
A Synergistic Approach For Evaluating Climate Model Output For Ecological Applications, Rachel D. Cavanagh, Eugene J. Murphy, Thomas J. Bracegirdle, John Turner, Cheryl A. Knowland, Stuart P. Corney, Walker O. Smith Jr., Claire M. Waluda, Nadine M. Johnston, Richard G. J. Bellerby, Eileen E. Hofmann
A Synergistic Approach For Evaluating Climate Model Output For Ecological Applications, Rachel D. Cavanagh, Eugene J. Murphy, Thomas J. Bracegirdle, John Turner, Cheryl A. Knowland, Stuart P. Corney, Walker O. Smith Jr., Claire M. Waluda, Nadine M. Johnston, Richard G. J. Bellerby, Eileen E. Hofmann
CCPO Publications
Increasing concern about the impacts of climate change on ecosystems is prompting ecologists and ecosystem managers to seek reliable projections of physical drivers of change. The use of global climate models in ecology is growing, although drawing ecologically meaningful conclusions can be problematic. The expertise required to access and interpret output from climate and earth system models is hampering progress in utilizing them most effectively to determine the wider implications of climate change. To address this issue, we present a joint approach between climate scientists and ecologists that explores key challenges and opportunities for progress. As an exemplar, our focus …
Mechanism Of Seasonal Arctic Sea Ice Evolution And Arctic Amplification, Kwang-Yul Kim, Benjamin D. Hamlington, Hanna Na, Jinju Kim
Mechanism Of Seasonal Arctic Sea Ice Evolution And Arctic Amplification, Kwang-Yul Kim, Benjamin D. Hamlington, Hanna Na, Jinju Kim
CCPO Publications
Sea ice loss is proposed as a primary reason for the Arctic amplification, although the physical mechanism of the Arctic amplification and its connection with sea ice melting is still in debate. In the present study, monthly ERA-Interim reanalysis data are analyzed via cyclostationary empirical orthogonal function analysis to understand the seasonal mechanism of sea ice loss in the Arctic Ocean and the Arctic amplification. While sea ice loss is widespread over much of the perimeter of the Arctic Ocean in summer, sea ice remains thin in winter only in the Barents-Kara seas. Excessive turbulent heat flux through the sea …
The Effects Of Changing Winds And Temperatures On The Oceanography Of The Ross Sea In The 21st Century, Walker O. Smith, Michael S. Dinniman, Eileen E. Hofmann, John M. Klinck
The Effects Of Changing Winds And Temperatures On The Oceanography Of The Ross Sea In The 21st Century, Walker O. Smith, Michael S. Dinniman, Eileen E. Hofmann, John M. Klinck
CCPO Publications
The Ross Sea is critically important in regulating Antarctic sea ice and is biologically productive, which makes changes in the region's physical environment of global concern. We examined the effects of projected changes in atmospheric temperatures and winds on aspects of the ocean circulation likely important to primary production using a high-resolution sea ice-ocean-ice shelf model of the Ross Sea. The modeled summer sea-ice concentrations decreased by 56% by 2050 and 78% by 2100. The duration of shallow mixed layers over the continental shelf increased by 8.5 and 19.2days in 2050 and 2100, and the mean summer mixed layer depths …
Sensitivity Of Circumpolar Deep Water Transport And Ice Shelf Basal Melt Along The West Antarctic Peninsula To Changes In The Winds, Michael S. Dinniman, John M. Klinck, Eileen E. Hofmann
Sensitivity Of Circumpolar Deep Water Transport And Ice Shelf Basal Melt Along The West Antarctic Peninsula To Changes In The Winds, Michael S. Dinniman, John M. Klinck, Eileen E. Hofmann
CCPO Publications
Circumpolar Deep Water (CDW) can be found near the continental shelf break around most of Antarctica. Advection of this relatively warm water (up to 2 degrees C) across the continental shelf to the base of floating ice shelves is thought to be a critical source of heat for basal melting in some locations. A high-resolution (4 km) regional ocean-sea ice-ice shelf model of the west Antarctic Peninsula (WAP) coastal ocean was used to examine the effects of changes in the winds on across-shelf CDW transport and ice shelf basal melt. Increases and decreases in the strength of the wind fields …
Oceanic Controls On The Mass Balance Of Wilkins Ice Shelf, Antarctica, Laurie Padman, Daniel P. Costs, M. S. Dinniman, Helen A. Fricker, Michael E. Goebel, Luis A. Huckstadt, Angelika Humbert, Ian Joughin, Jan T. M. Lenaerts, Stefan R. M. Ligtenberg, Ted Scambos, Michiel R. Van Den Broeke
Oceanic Controls On The Mass Balance Of Wilkins Ice Shelf, Antarctica, Laurie Padman, Daniel P. Costs, M. S. Dinniman, Helen A. Fricker, Michael E. Goebel, Luis A. Huckstadt, Angelika Humbert, Ian Joughin, Jan T. M. Lenaerts, Stefan R. M. Ligtenberg, Ted Scambos, Michiel R. Van Den Broeke
CCPO Publications
Several Antarctic Peninsula (AP) ice shelves have lost significant fractions of their volume over the past decades, coincident with rapid regional climate change. Wilkins Ice Shelf (WIS), on the western side of the AP, is the most recent, experiencing a sequence of large calving events in 2008 and 2009. We analyze the mass balance for WIS for the period 1992-2008 and find that the averaged rate of ice-shelf thinning was similar to 0.8 m a(-1), driven by a mean basal melt rate of < w(b)> = 1.3 +/- 0.4 m a(-1). Interannual variability was large, associated with changes in both surface mass …
Modeling The Growth Dynamics Of Antarctic Krill Euphausia Superba, Eileen E. Hofmann, Cathy M. Lascara
Modeling The Growth Dynamics Of Antarctic Krill Euphausia Superba, Eileen E. Hofmann, Cathy M. Lascara
CCPO Publications
A time-dependent, size-structured, bioenergetically based model was developed to examine the growth dynamics of Antarctic krill Euphausia superba 2 to 60 mm in size. The metabolic processes included in the model are ingestion, a baseline respiration, respiratory losses due to feeding and digestion, and an activity-based respiration factor. The total of these processes, net production, was used as the basis for determining the growth or shrinkage of individuals. Size-dependent parameterizations for the metabolic processes were constructed from field and laboratory measurements. Environmental effects were included through time series of pelagic phytoplankton concentration that were derived from data sets collected west …
Heat And Salt Changes On The Continental Shelf West Of The Antarctic Peninsula Between January 1993 And January 1994, John M. Klinck
Heat And Salt Changes On The Continental Shelf West Of The Antarctic Peninsula Between January 1993 And January 1994, John M. Klinck
CCPO Publications
Hydrographic measurements from four cruises between January 1993 and January 1994 over the continental shelf west of the Antarctic Peninsula allow analysis of seasonal changes in heat and salt content of this region. Changes above the permanent pycnocline (about 150 m) follow a seasonal pattern of cooling and increasing in salt from summer to winter and warming and freshening from winter to summer. These near-surface changes expressed as net heating or salting rate, were above 80 W m(-2) and 4 mg salt m(-2) s(-1). The year to year difference was small compared to the seasonal changes. There was no seasonal …