Geographical distribution of living planktonic foraminifera (Protozoa) off the east coast of Australia.

1988 ◽  
Vol 39 (1) ◽  
pp. 71 ◽  
Author(s):  
S Andrijanic
Keyword(s):  
Sea Water ◽  
Planktonic Foraminifera ◽  
Distribution Patterns ◽  
Water Masses ◽  
Individual Species ◽  
The South ◽  
The North ◽  
Warm Core ◽  
Tasman Sea ◽  
Eastern Australia

Major water masses found off eastern Australia can be identified by their planktonic foraminiferal faunas. A total of 83 surface and oblique plankton samples from two cruises, in spring (October) and summer (January), between Hobart at 44� S. and Townsville at 18� S. yielded 27 species belonging to four distinct faunas: 'tropical', 'warm subtropical', 'cool subtropical' and 'transitional'. The tropical fauna is characterized by Globigerinoides sacculifer at an abundance greater than 42% and the co- dominance of Globigerinoides conglobatus, and is associated with Coral Sea water of equatorial origin. The subtropical fauna can be subdivided into warm and cool elements. The warm-subtropical fauna, with G. sacculifer more abundant than Globigerinoides ruber, inhabits Coral and Tasman Sea waters. The cool-subtropical fauna is a mixture of the warm subtropical and the transitional faunas. The transitional fauna is dominated by Globorotalia inflata and Globigerina bulloides in the south Tasman Sea subantarctic waters. It characterizes the South West Tasman water as defined by Rochford (1957). These water masses can be clearly separated, and the extent of mixing determined by their foraminiferal fauna. The shifts in the boundaries between the faunal zones was evident between spring and summer. The boundary between the tropical and subtropical water corresponds to the tropical convergence and the subtropical/transitional boundary is the Tasman Front. During the spring cruise, a warm core eddy was identified by its warm subtropical foraminiferal fauna surrounded by a transitional fauna to the south and cool subtropical fauna to the north. This water body was near 32� S., which is consistent with the reported positions of eddies shed by the East Australian Current. The distribution patterns of individual species are discussed.

The Identification and Nomenclature of the Surface Water Masses in the Tasman Sea (Data to the End of 1954)

1957 ◽  
Vol 8 (4) ◽  
pp. 369 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Surface Water ◽  
Sea Water ◽  
Maximum Velocity ◽  
Water Masses ◽  
Late Winter ◽  
The South ◽  
Coral Sea ◽  
Tasman Sea ◽  
East And West ◽  
Western Side

In this paper an examination of all available data on the hydrological characteristics of the Tasman Sea, prior to and including the year 1954, has permitted the identification and naming of eight surface water masses. Certain of their properties and general features of their season and region of occurrence and method of formation are summarized. Although little quantitative data are available some general features of the circulation of these water masses in the Tasman Sea are deduced from a study of their seasonal occurrence in relation to source regions. The Coral Sea water mass (chlorinity 19.60-19.70‰, temperature 20-26� C) flows from a source region in the north-west Coral Sea along the western side of the Tasman Sea and reaches maximum velocity off Sydney in October-December. The South Equatorial (chlorinity 19.50-19.60‰, temperature 24-26� C) also flows south along the western side of the Tasman Sea but reaches maximum velocity between February and March. These two water masses constitute the East Australian current. The Sub-Antarctic (chlorinity 19.15-19.30‰, temperature 10-14°C) is found at the surface in the south-eastern Tasman Sea between July and September. The Central Tasman (chlorinity 19.65-19.75‰, temperature 15-20‰C) flows to the west from its region of formation and generally flows north along the southern New South Wales coast in late winter. The South-west Tasman (chlorinity 19.50- 19.60‰, temperature 12-15°C) flows to the east in latitude 38�S. and curves south in a clockwise gyral off eastern Tasmania between October and December. The Xorth Bass Strait (chlorinity 19.66-19.75‰ temperature 12-17�C) flows from South Australia to the eastern approaches of Bass Strait. The East Central New Zealand (chlorinity 19.10-19.30‰, temperature 15-20°C) flows west through Cook Strait into the Tasman Sea in midsummer. The East and West Tasmanian (chlorinity 19.40- 19.50‰ temperature 10-14°C) form in midwinter in the southern part of Bass Strait and flow along the east and west coasts in the spring.

Mesopelagic crustacea in and around a warm-core eddy in the Tasman Sea off eastern Australia

1983 ◽  
Vol 34 (4) ◽  
pp. 609 ◽  
Author(s):  
FB Griffiths ◽  
SB Brandt
Keyword(s):  
Secondary Succession ◽  
Water Mass ◽  
Sea Water ◽  
Abundant Species ◽  
Frequency Distributions ◽  
Warm Core ◽  
Tasman Sea ◽  
Eastern Australia ◽  
Decapod Crustacea ◽  
Species Abundances

Decapod Crustacea were collected during five cruises (in August, September, and October 1979, February and May 1980) at sites inside, at the edge, and outside of warm-core eddy J. These sampling sites were considered to have come from different domains of the Tasman Sea water mass. All 146 samples in this time series were taken in the upper 500 m at night using horizontal tows with an RMT 8. A total of 21 494 individuals belonging to 41 species and five larval categories was found. Nine of the 18 abundant species were cosmopolitan species: typical of samples from outside, at the edge of, and inside eddy J. Oplophorus spinosus was typical only at the eddy edge. Four species were typical of the outside and edge domains, and another four were typical of the inside and edge domains. Species abundances outside the eddy were dominated by Sergia prehensilis, Gennadas gilchristi, and Acanthephyra quadrispinosa. The first two species, plus Systellaspis debilis, were dominant at the eddy edge. Six species (Systellaspis debilis, Sergia prehensilis, Sergia scintillans, Sergia splendens, Sergestes atlanticus, and Parapandalas cf. richardi) were dominant at various times inside the eddy. There were no significant differences in the abundance of Sergia prehensilis in the three domains. Systellaspis debilis was significantly more abundant inside and at the eddy edge than outside the eddy, and Gennadas gilchristi was significantly more abundant outside and at the eddy edge than inside the eddy. An analysis of the community changes with time showed that the outside communities remained very similar in spite of the 5°30' change in latitude of eddy J between August 1979 and May 1980. In contrast, the inside communities were quite dissimilar between months, and there was no trend in this pattern. The edge communities were very similar except in May, when a large increase in the abundance of Gennadas gilchristi was found. Comparisons of communities between domains within each month showed the outside and edge communities were very similar over the entire period. In contrast, the outside and inside communities became increasingly different in time, mainly caused by changes in the abundances of species inside the eddy. The inside and edge communities were also quite different, but no consistent pattern in their dissimilarity with time was seen. Differences in the size-frequency distributions of Sergla prehensilis and Systellaspis debilis between domains through time suggest that breeding and recruitment were occumng at different times inside and outside the eddy. There was little evidence for colonization of the eddy by Tasman Sea species. We conclude that a secondary succession has been initiated, probably in response to the different physical and biological environments present inside eddy J as compared with the surrounding Tasman Sea.

The Intermediate Depth Waters of the Tasman and Coral Seas. II.The 26.80σt surface

1960 ◽  
Vol 11 (2) ◽  
pp. 148 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Distribution Patterns ◽  
Intermediate Depth ◽  
The North ◽  
Winter Distribution ◽  
South West ◽  
Tasman Sea ◽  
Antarctic Convergence ◽  
Horizontal Mixing ◽  
The Antarctic ◽  
The Western Pacific

The distribution of salinity, dissolved oxygen, and phosphates on the 26.80 σt surface of the Tasman and Coral Seas is examined. The distribution patterns of these properties and the relations of salinity and phosphate and salinity and oxygen values are explained by horizontal mixing of three water types. These originated, one to the north of the Antarctic Convergence, one in the south-west Tasman, possibly in the Australian Bight, and one at the equator in the western Pacific. The major sinking regions and the circulation paths of subtropical waters in the Tasman Sea are deduced from their summer and winter distribution and from the topography of the 26.80 σt, surface.

Some zooplankton characteristics of warm-core eddies shed by the East Australian Current, with particular reference to copepods

1983 ◽  
Vol 34 (4) ◽  
pp. 587 ◽  
Author(s):  
DJ Tranter ◽  
DJ Tafe ◽  
RL Sandland
Keyword(s):  
Free Fall ◽  
Dry Weight ◽  
Physical Structure ◽  
East Australian Current ◽  
The South ◽  
Warm Core ◽  
Tasman Sea

Several eddies in the south-western Tasman Sea were investigated to see whether they differed faunistically from the seas around them. Zooplankton samples (0-200 m) were taken by free-fall net for dry weight measurements and copepod analyses. The counts obtained for 20 species of copepod were used to classify 51 stations into (eight) groups. These were taken to constitute the major zooplankton habitats in the study area. These habitats corresponded in most respects with the known physical structure of the study area. Eddies were faunistically distinct from the seas that surrounded them. Eddy J was similar in 1979-1980 to the waters of the East Australian Current, which were periodically entrained within the eddy circulation. There were significant faunal differences between eddy J and eddy F, an isolated eddy sampled in December 1978.

scholarly journals The distribution of DMSP in green macroalgae from northern New Zealand, eastern Australia and southern Tasmania

2008 ◽  
Vol 88 (4) ◽  
pp. 799-805 ◽  
Author(s):  
Kathryn L. Van Alstyne
Keyword(s):  
New Zealand ◽  
Distribution Patterns ◽  
Whole Body ◽  
Green Macroalgae ◽  
Geographical Patterns ◽  
Non Invasive ◽  
The North ◽  
Eastern Australia ◽  
High Concentrations ◽  
Host Alga

The sulphonium compound dimethylsulphoniopropionate (DMSP) is commonly found in temperate green macroalgae. To examine taxonomic and regional and local geographical patterns of DMSP production in Australasian algae, I collected 30 species of green algae from 14 sites in three regions, eastern Australia, Tasmania, Australia, and the North Island of New Zealand. The distribution of DMSP content was similar to that seen from other areas of the world. DMSP was found in high concentrations in Ulva and Codium spp. It tended to be undetectable or in lower concentrations in other members of the orders Bryopsidales and Cladophorales. There was no evidence for differences in concentrations among the three regions in the genera Codium and Ulva; however, the invasive subspecies of Codium fragile, C. fragile ssp. tomentosoides, had significantly higher concentrations of DMSP than the non-invasive subspecies. The herbivorous sea slug Elysia maoria had whole body concentrations that were not significantly different from those of its host alga C. fragile ssp. tomentosoides. The distribution patterns of DMSP in Codium spp. do not support the hypothesis that DMSP is used as an antioxidant in this genus. Based on the data collected here and previous reports from the literature, I speculate that one function of DMSP in these algae may be to deter herbivores.

scholarly journals A Climatology of Subtropical Cyclones in the South Atlantic

2012 ◽  
Vol 25 (21) ◽  
pp. 7328-7340 ◽  
Author(s):  
Jenni L. Evans ◽  
Aviva Braun
Keyword(s):  
North Atlantic ◽  
Warm Season ◽  
Hybrid Structure ◽  
South Atlantic ◽  
The South ◽  
Rossby Wave Breaking ◽  
The North ◽  
Brazil Current ◽  
Eastern Australia ◽  
Upper Level

A 50-yr climatology (1957–2007) of subtropical cyclones (STs) in the South Atlantic is developed and analyzed. A subtropical cyclone is a hybrid structure (upper-level cold core and lower-level warm core) with associated surface gale-force winds. The tendency for warm season development of North Atlantic STs has resulted in these systems being confused as tropical cyclones (TCs). In fact, North Atlantic STs are a regular source of the incipient vortices leading to North Atlantic TC genesis. In 2004, Hurricane Catarina developed in the South Atlantic and made landfall in Brazil. A TC system had been previously unobserved in the South Atlantic, so the incidence of Catarina highlighted the lack of an ST climatology for the region to provide a context for the likelihood of future systems. Sixty-three South Atlantic STs are documented over the 50-yr period analyzed in this climatology. In contrast to the North Atlantic, South Atlantic STs occur relatively uniformly throughout the year; however, their preferred location of genesis and mechanisms for this genesis do exhibit some seasonal variability. Rossby wave breaking was identified as the mechanism for the ST vortex initiation for North Atlantic STs. A subset of South Atlantic STs forms via this mechanism, however, an additional mechanism for ST genesis is identified here: lee cyclogenesis downstream of the Andes in the Brazil Current region—an area favorable for convection. This formation mechanism is similar to development of type-2 east coast lows in the Tasman Sea off eastern Australia.

Bass Strait water intrusions in the Tasman Sea and mean temperature-salinity curves

1981 ◽  
Vol 32 (5) ◽  
pp. 699 ◽  
Author(s):  
M Tomczak Jr
Keyword(s):  
Water Mass ◽  
East Australian Current ◽  
Shelf Edge ◽  
The South ◽  
The North ◽  
Mean Temperature ◽  
Tasman Sea

At temperatures of 8-18�C mean temperature-salinity curves for the Tasman Sea show slightly higher salinities in the south than in the north. It is shown that this is the effect of intrusions of Bass Strait Water which enters the Tasman Sea predominantly in winter and can be traced in individual stations over distances of 600 nautical miles along the shelf edge and 200 nautical miles offshore. The paths of individual intrusions and the degree of mixing are highly variable and seem to depend, among other factors, on the path of the East Australian Current and its eddies. This is interpreted as an indication that the eddies may play a major role in the formation of the water-mass characteristics of the Tasman Sea.

scholarly journals High resolution modelling of the North Icelandic Irminger Current (NIIC)

2006 ◽  
Vol 3 (4) ◽  
pp. 1149-1189 ◽  
Author(s):  
K. Logemann ◽  
I. H. Harms
Keyword(s):  
Heat Flux ◽  
Heat Transport ◽  
Heat Fluxes ◽  
Water Masses ◽  
Coastal Current ◽  
The South ◽  
Arctic Water ◽  
The North ◽  
Denmark Strait ◽  
Irminger Current

Abstract. The northward inflow of Atlantic Water through Denmark Strait – the North Icelandic Irminger Current (NIIC) – is simulated with a numerical model of the North Atlantic and Arctic Ocean. The model uses the technique of adaptive grid refinement which allows a high spatial resolution (1 km horizontal, 10 m vertical) around Iceland. The model is used to assess time and space variability of volume and heat fluxes for the years 1997–2003. Passive tracers are applied to study origin and composition of NIIC water masses. The NIIC originates from two sources: the Irminger Current, flowing as part of the sub-polar gyre in 100–500 m depth along the Reykjanes Ridge and the shallow Icelandic coastal current, flowing eastward on the south Icelandic shelf. The ratio between the deep and shallow branch is 0.7/0.2 Sv. The NIIC continues as a warm and saline branch northward through Denmark Strait where it entrains large amounts of polar water due to the collision with the southward flowing East Greenland Current. Tracer model results indicate that north of Denmark Strait at Hornbanki section (at 21°30' W from 66°40' N to 67°30' N), the NIIC is composed of 43% water masses of Atlantic origin (AW) originating from the south and 57% entrained polar or Arctic water masses (PW) coming from the north. After passing Denmark Strait, the NIIC follows the coast line north-eastward where it influences the hydrography of north Icelandic waters. Volume and heat transport is highly variable and depends strongly on the wind field north of Denmark Strait. Highest monthly mean transport rates at Hornbanki occur in summer (0.75 Sv) when northerly winds are weak, lowest transport is observed in winter (0.35 Sv). Summer heat flux rates (14 TW) can be even three times higher than in winter (4 TW). Strong variability can also be observed on the interannual scale. In particular the winter 2002/2003 showed anomalous high transport and heat flux rates. During the period 1997 to 2003 decreasing northerly winds caused an increase of the NIIC volume and heat transport by 30%, leading to a warming of North Icelandic shelf by around 0.5K.

scholarly journals Water masses in the Atlantic Ocean: characteristics and distributions

Ocean Science ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 463-486
Author(s):  
Mian Liu ◽  
Toste Tanhua
Keyword(s):  
Atlantic Ocean ◽  
Deep Water ◽  
Bottom Water ◽  
Water Mass ◽  
Sea Water ◽  
Weddell Sea ◽  
Water Masses ◽  
Global Ocean ◽  
Intermediate Water ◽  
The North

Abstract. A large number of water masses are presented in the Atlantic Ocean, and knowledge of their distributions and properties is important for understanding and monitoring of a range of oceanographic phenomena. The characteristics and distributions of water masses in biogeochemical space are useful for, in particular, chemical and biological oceanography to understand the origin and mixing history of water samples. Here, we define the characteristics of the major water masses in the Atlantic Ocean as source water types (SWTs) from their formation areas, and map out their distributions. The SWTs are described by six properties taken from the biased-adjusted Global Ocean Data Analysis Project version 2 (GLODAPv2) data product, including both conservative (conservative temperature and absolute salinity) and non-conservative (oxygen, silicate, phosphate and nitrate) properties. The distributions of these water masses are investigated with the use of the optimum multi-parameter (OMP) method and mapped out. The Atlantic Ocean is divided into four vertical layers by distinct neutral densities and four zonal layers to guide the identification and characterization. The water masses in the upper layer originate from wintertime subduction and are defined as central waters. Below the upper layer, the intermediate layer consists of three main water masses: Antarctic Intermediate Water (AAIW), Subarctic Intermediate Water (SAIW) and Mediterranean Water (MW). The North Atlantic Deep Water (NADW, divided into its upper and lower components) is the dominating water mass in the deep and overflow layer. The origin of both the upper and lower NADW is the Labrador Sea Water (LSW), the Iceland–Scotland Overflow Water (ISOW) and the Denmark Strait Overflow Water (DSOW). The Antarctic Bottom Water (AABW) is the only natural water mass in the bottom layer, and this water mass is redefined as Northeast Atlantic Bottom Water (NEABW) in the north of the Equator due to the change of key properties, especially silicate. Similar with NADW, two additional water masses, Circumpolar Deep Water (CDW) and Weddell Sea Bottom Water (WSBW), are defined in the Weddell Sea region in order to understand the origin of AABW.

Mosses and the Tyrolean Iceman’s southern provenance

1996 ◽  
Vol 263 (1370) ◽  
pp. 567-571 ◽  
Keyword(s):  
Distribution Patterns ◽  
The South ◽  
The North ◽  
Low Altitude

The Tyrolean Iceman’s clothes have yielded remains of a total of 30 different bryophytes (mosses and liverworts), at least nine of which could not have grown at the great altitude of the death site. Most crucial are the two low altitude woodland mosses Neckera complanata and N. crispa . Their distribution patterns in Tyrol indicate strongly that the Iceman came from the south (modern Italy) rather than the north (Austria).

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