96 research outputs found
The 'Literary Selfie' meets Literary Studies: Reading The Permanent Resident (2016) with Roanna Gonsalves and students of Writing Australia 2017 Queensland University of Technology
AbstractThis paper adds to the ongoing dialogue between the schools of creative writing and literary studies while exploring the relationship between reading and writing Australian literature through a case study of Roanna Gonsalvesâ short story collection The Permanent Resident. Gonsalvesâ collection writes back to dominant narratives around the Indian-Australian and Indian-Goan Australian diaspora within contemporary Australian society. It relates to four of the themes from this yearâs conference, ASAL (Virtual) 2020 Reading and Writing Australian Literature. The themes are: teaching Australian writing, literary criticism, representing diversity and writing Australia. I argue The Permanent Resident is a collection worthy of a literary criticism class as well as a creative writing class as borne out by an interview conducted with the author by QUT Creative Writing and Literary Studies students via email
Rapid communication of upperâocean salinity anomaly to deep waters of the Iceland Basin indicates an AMOC shortâcut
The mooring observations of the Overturning in the Subpolar North Atlantic Program reveal a significant freshening of the Iceland Scotland overflow waters that did not involve the Nordic Seas, the source of the dense Deep North Atlantic Water (Devana et al., 2021, https://doi.org/10.1029/2021GL094396). Their study suggests that this freshening at depth in the Iceland Basin stems from the largest upper-ocean freshening event in 120 years that rapidly communicated through entrainment with the Iceland Scotland Overflow Waters. This communication, which is very likely driven by strong wintertime heat losses, strongly adds to our thinking that the progression of this extreme freshening event is providing us with a natural tracer that is helping to identify and understand key processes that determine the strength and variability of the overturning circulation and its sensitivity to ongoing climate change. Continued monitoring of the overturning in the North Atlantic is therefore necessary
The retroflection of part of the East Greenland Current at Cape Farewell
The East Greenland Current (EGC) and the smaller East Greenland Coastal Current (EGCC) provide the major conduit for cold fresh polar water to enter the lower latitudes of the North Atlantic. They flow equatorward through the western Irminger Basin and around Cape Farewell into the Labrador Sea. The surface circulation and transport of the Cape Farewell boundary current region in summer 2005 is described. The EGCC merges with Arctic waters of the EGC to the south of Cape Farewell, forming the West Greenland Current. The EGC transport decreases from 15.5 Sv south of Cape Farewell to 11.7 Sv in the eastern Labrador Sea (where the water becomes known as Irminger Sea Water). The decrease in EGC transport is balanced by the retroflection of a substantial proportion of the boundary current (5.1 Sv) into the central Irminger Basin; a new pathway for fresh water into the interior of the subpolar gyre
Arctic Ocean and Hudson Bay freshwater exports: New estimates from 7 decades of hydrographic surveys on the Labrador Shelf
While reasonable knowledge of multi-decadal Arctic freshwater storage variability exists, we have little knowledge of Arctic freshwater exports on similar timescales. A hydrographic time series from the Labrador Shelf, spanning seven decades at annual resolution, is here used to quantify Arctic Ocean freshwater export variability west of Greenland. Output from a high-resolution coupled ice-ocean model is used to establish the representativeness of those hydrographic sections. Clear annual to decadal variability emerges, with high freshwater transports during the 1950s and 1970sâ80s, and low transports in the 1960s, and from the mid-1990s to 2016, with typical amplitudes of 30 mSv (1 Sv = 106 m3 s-1). The variability in both the transports and cumulative volumes correlates well both with Arctic and North Atlantic freshwater storage changes on the same timescale. We refer to the "inshore branch" of the Labrador Current as the Labrador Coastal Current, because it is a dynamically- and geographically-distinct feature. It originates as the Hudson Bay outflow, and preserves variability from river runoff into the Hudson Bay catchment. We find a need for parallel, long-term freshwater transport measurements from Fram and Davis Straits, to better understand Arctic freshwater export control mechanisms and partitioning of variability between routes west and east of Greenland, and a need for better knowledge and understanding of year-round (solid and liquid) freshwater fluxes on the Labrador shelf. Our results have implications for wider, coherent atmospheric control on freshwater fluxes and content across the Arctic and northern North Atlantic Oceans
North Atlantic extratropical and subpolar gyre variability during the last 120 years: a gridded dataset of surface temperature, salinity, and density. Part 1: dataset validation and RMS variability
We present a binned annual product (BINS) of sea surface temperature (SST), sea surface salinity (SSS), and sea surface density (SSD) observations for 1896â2015 of the subpolar North Atlantic between 40° N and 70° N, mostly excluding the shelf areas. The product of bin averages over spatial scales on the order of 200 to 500 km, reproducing most of the interannual variability in different time series covering at least the last three decades or of the along-track ship monitoring. Comparisons with other SSS and SST gridded products available since 1950 suggest that BINS captures the large decadal to multidecadal variability. Comparison with the HadSST3 SST product since 1896 also indicates that the decadal and multidecadal variability is usually well-reproduced, with small differences in long-term trends or in areas with marginal data coverage in either of the two products. Outside of the Labrador Sea and Greenland margins, interannual variability is rather similar in different seasons. Variability at periods longer than 15 years is a large part of the total interannual variability, both for SST and SSS, except possibly in the south-western part of the domain. Variability in SST and SSS increases towards the west, with the contribution of salinity variability to density dominating that of temperature in the western Atlantic, except close to the Gulf Stream and North Atlantic Current in the southwest area. Weaker variability and larger relative temperature contributions to density changes are found in the eastern part of the gyre and south of Iceland
Observed deep cyclonic eddies around Southern Greenland
Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 51(10), (2021): 3235â3252, https://doi.org/10.1175/JPO-D-20-0288.1.Recent mooring measurements from the Overturning in the Subpolar North Atlantic Program have revealed abundant cyclonic eddies at both sides of Cape Farewell, the southern tip of Greenland. In this study, we present further observational evidence, from both Eulerian and Lagrangian perspectives, of deep cyclonic eddies with intense rotation (ζ/f > 1) around southern Greenland and into the Labrador Sea. Most of the observed cyclones exhibit strongest rotation below the surface at 700â1000 dbar, where maximum azimuthal velocities are ~30 cm sâ1 at radii of ~10 km, with rotational periods of 2â3 days. The cyclonic rotation can extend to the deep overflow water layer (below 1800 dbar), albeit with weaker azimuthal velocities (~10 cm sâ1) and longer rotational periods of about one week. Within the middepth rotation cores, the cyclones are in near solid-body rotation and have the potential to trap and transport water. The first high-resolution hydrographic transect across such a cyclone indicates that it is characterized by a local (both vertically and horizontally) potential vorticity maximum in its middepth core and cold, fresh anomalies in the deep overflow water layer, suggesting its source as the Denmark Strait outflow. Additionally, the propagation and evolution of the cyclonic eddies are illustrated with deep Lagrangian floats, including their detachments from the boundary currents to the basin interior. Taken together, the combined Eulerian and Lagrangian observations have provided new insights on the boundary current variability and boundaryâinterior exchange over a geographically large scale near southern Greenland, calling for further investigations on the (sub)mesoscale dynamics in the region.OOI mooring data are based upon work supported by the National Science Foundation under Cooperative Agreement 1743430. S. Zou, A. Bower, and H. Furey gratefully acknowledge the support from the Physical Oceanography Program of the U.S. National Science Foundation Grant OCE-1756361. R.S. Pickart acknowledges support from National Science Foundation Grants OCE-1259618 and OCE-1756361. N. P. Holliday and L. Houpert were supported by NERC programs U.K. OSNAP (NE/K010875) and U.K. OSNAP-Decade (NE/T00858X/1)
A regional thermohaline inverse method for estimating circulation and mixing in the Arctic and subpolar North Atlantic
A Regional Thermohaline Inverse Method (RTHIM) is presented that estimates velocities through the section bounding an enclosed domain and transformation rates due to interior mixing within the domain, given inputs of surface boundary fluxes of heat and salt and interior distributions of salinity and temperature. The method works by invoking a volumetric balance in thermohaline coordinates between the transformation due to mixing, surface fluxes and advection, while constraining the mixing to be down tracer gradients. The method is validated using a 20-year mean of outputs from the NEMO model in an Arctic and subpolar North Atlantic domain, bound to the south by a section with a mean latitude of 66°N. RTHIM solutions agree well with the NEMO model âtruthâ and are robust to a range of parameters; the MOC, heat and freshwater transports calculated from an ensemble of RTHIM solutions are within 12%, 10% and 19%, respectively, of the NEMO values. There is also bulk agreement between RTHIM solution transformation rates due to mixing and those diagnosed from NEMO. Localized differences in diagnosed mixing may be used to guide the development of mixing parameterizations in models such as NEMO, whose downgradient diffusive closures with prescribed diffusivity may be considered oversimplified and too restrictive
Atlantic overturning: new observations and challenges
This paper provides an introduction to the special issue of the Philosophical Transactions of the Royal Society of London of papers from the 2022 Royal Society meeting on âAtlantic overturning: new observations and challenges'. It provides the background and rationale for the meeting, briefly summarizes prior progress on observing the Atlantic overturning circulation and draws out the new challenges that papers presented at the meeting raise, so pointing the way forward for future research.
This article is part of a discussion meeting issue 'Atlantic overturning: new observations and challenges'
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