OCEAN > INDIAN OCEAN
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This csv details the raw Argos locations generated from satellite tags attached to pygmy blue whales in order to describe their migratory movements through Australian waters as described in: Double MC, Andrews-Goff V, Jenner KCS, Jenner M-N, Laverick SM, et al. (2014) Migratory Movements of Pygmy Blue Whales (Balaenoptera musculus brevicauda) between Australia and Indonesia as Revealed by Satellite Telemetry. PLoS ONE 9(4): e93578. doi:10.1371/journal.pone.0093578 This csv includes the following data fields - ptt: the unique Argos identifier assigned to each satellite tag gmt: the date and time in gmt with the format 'yyyy-mm-dd hh:mm:ss' class: the Argos assigned location class (see paper for details) latitude longitude deploydate: deployment date and time in gmt for each tag with the format 'yyyy-mm-dd hh:mm:ss' filt: the outcome of the sdafilter (see paper for details) - either "removed" (location removed by the filter), "not" (location not removed) or "end_location" (location at the end of the track where the algorithm could not be applied)
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We studied the gut contents of four dominant copepod species (Calanoides acutus, Calanus propinquus, Calanus simillimus and Rhincalanus gigas) during the summer (2014-2015) along a latitudinal gradient (sampled every 5° between 40°S and 65°S) in the Indian sector of the SO. Diatoms were the most abundant food item found in the guts, comprising 24 of the 25 species found, and 15 were common to the four species of copepod studied. Diatoms accounted for the lowest proportion of the diet in the warmer, northern waters while all the large diatoms (e.g. Chaetoceros atlanticus, C. criophilus, C. dichaeta, Corethron spp.) were only found at 65oS. The most frequent species in the guts were the centric diatoms Thalassiosira spp. (4 to 57%) and the pennate diatoms Fragilariopsis kerguelensis (27 to 80%) and Trichoctoxon reinboldii (2 to 50%); proportions varied within a species across locations. These species were found at all sites examined, whereas some diatoms were specific to one copepod species: Asteromphalus spp. (in R. gigas), C. criophilus and C. dichaeta (in C. acutus), Nitzschia lecointei and N. sicula (in C. propinquus).
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Zooplankton were collected during the winter-spring transition during two cruises of the Aurora Australis: SIPEX in 2007 and SIPEX II in 2012. As part of the collections sea ice cores were collected to describe the ice habitat during the period of zooplankton collections. Ice cores were taken with a 20 cm diameter SIPRE corer and sectioned in the field with an ice core. Temperature was measured in the section using a spike thermometer and slivers of each section were melted without filtered water to record salinity. The remainders of each section were melted at 4oC in filtered seawater and the melted water was used to measure chlorophyll a concentration, and meiofauna species and abundance. Meiofauna were counted and identified using a Leica M12 microscope: to species in most cases and down to stage during 2012.
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An R data file containing a hierarchical switching state-space model of pygmy blue whale Argos-collected telemetry data using the bsam package (see Jonsen (2016). Joint estimation over multiple individuals improves behavioural state inference from animal movement data. Scientific Reports 6: 20625.) in R. The model estimated location states for each individual at regular 3-h time intervals, accounting for measurement error in the irregularly observed Argos surface locations; and estimated the behavioural state associated with each location. Satellite tags were deployed on pygmy blue whales located in the Bonney Upwelling region, SA, between 7 January and 16 March 2015. File can be opened in R (A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/ ) using the code: readRDS('bw_3h_ssm.RDS')
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GEBCO’s (General Bathymetric Chart of the Oceans) gridded bathymetric data set, the GEBCO_2019 Grid, is a global terrain model for ocean and land, providing elevation data, in meters, on a 15 arc-second interval grid. The GEBCO 2019 grid is reformatted as a Cloud Optimised GeoTIFF suitable for online requests and republished for use primarily by software development. Original GEBCO grid was obtained from https://www.gebco.net/data_and_products/gridded_bathymetry_data/gebco_2019/gebco_2019_info.html
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The GEBCO_2021 Grid provides global coverage of elevation data in meters on a 15 arc-second grid of 43200 rows x 86400 columns, giving 3,732,480,000 data points. The GEBCO 2021 grid is reformatted as a Cloud Optimised GeoTIFF suitable for online requests and republished for use by science software. Original GEBCO grid was obtained from https://www.gebco.net/data_and_products/gridded_bathymetry_data/gebco_2021/
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Zooplankton were collected during the winter-spring transition during two cruises of the Aurora Australis: SIPEX in 2007 and SIPEX II in 2012. To determine size and biomass, key species were measured. Measurements of Prosome, Urosome and Total length are provided. The zooplankton were taken from samples collected with umbrella nets, RMT1 net and sea ice cores. They were measured under a Leica M165C steromicroscope using an ocular micrometer. The ocular micrometer was calibrated against a stage micrometer (+/- 0.01 um).
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Zooplankton were collected during the winter-spring transition during two cruises of the Aurora Australis: SIPEX in 2007 and SIPEX II in 2012. As part of the collections sea ice cores were collected to describe the ice habitat during the period of zooplankton collections. Ice cores were taken with a 20 cm diameter SIPRE corer and sectioned in the field with an ice core. Temperature was measured in the section using a spike thermometer and slivers of each section were melted without filtered water to record salinity. The remainders of each section were melted at 4oC in filtered seawater and the melted water was used to measure chlorophyll a concentration, and meiofauna species and abundance.
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Metadata record for data expected ASAC Project 1207 See the link below for public details on this project. ---- Public Summary from Project ---- Project title: 'Effects of variability in ocean surface forcing on the properties of SAMW and AAIW in the South Indian Ocean' This project will study the formation and subduction processes and the properties of Antarctic Intermediate Water and Sub-Antarctic Mode Water as simulated by an Ocean General Circulation model, with particular reference to the South Indian Ocean. The study will attempt to determine how its formation and properties are affected by interannual variations in SST and wind forcing and by differing prescriptions of mixing and convection processes occurring in mid-to high latitude oceanic frontal regions of the Southern Ocean. The investigation of the ocean response in the Indian Ocean will profit from the use of a model employing general orthogonal coordinates and efficient variable resolution grids which are global but concentrated in the Indian sector. From the abstracts of the referenced papers: This article considers how some of the measures used to overcome numerical problems near the North Pole affect the ocean solution and computational time step limits. The distortion of the flow and tracer contours produced by a polar island is obviated by implementing a prognostic calculation for a composite polar grid cell, as has been done at NCAR. The severe limitation on time steps caused by small zonal grid spacing near the pole is usually overcome by Fourier filtering, sometimes supplemented by the downward tapering of mixing coefficients as the pole is approached; however, filtering can be expensive, and both measures adversely affect the solution. Fourier filtering produces noise, which manifests itself in such effects as spurious static instabilities and vertical motions; this noise can be due to the separate and different filtering of internal and external momentum modes and tracers, differences in the truncation at different latitudes, and differences in the lengths of filtering rows, horizontally and vertically. Tapering has the effect of concentrating tracer gradients and velocities near the pole, resulting in some deformation of fields. In equilibrium ocean models, these effects are static and localised in the polar region, but with time-varying forcings or coupling to atmosphere and sea ice it is possible that they may seriously affect the global solution. The marginal stability curve in momentum and tracer time-step space should have asymptotes defined by diffusive, viscous, and internal gravity wave stability criteria; at large tracer time steps, tracer advection stability may become limiting. Tests with various time-step combinations and a flat-bottomed Arctic Ocean have confirmed the applicability of these limits and the predicted effects of filtering and tapering on them. They have also shown that the need for tapering is obviated by substituting a truncation which maintains a constant time step limit rather than a constant minimum wave number over the filtering range. Continuous and finite difference forms of the governing equations are derived for a version of the Bryan-Cox-Semtner ocean general circulation model which has been recast in orthogonal, transversely curvilinear coordinates. The coding closely follows the style of the Geophysical Fluid Dynamics Laboratory modular ocean model No. 1. Curvilinear forms are given for the tracer, internal momentum, and stream function calculations, with the options of horizontal and isopycnal diffusion, eddy-induced transport, nonlinear viscosity, and semiimplicit treatment of the Coriolis force. The model is designed to operate on a rectangular three-dimensional array of points and can accomodate reentrant boundary conditions at both 'northern' and 'east-west' boundaries. Horizontal grid locations are taken as input and need to be supplied by a separate grid generation program. The advantages of using a better behaved and more economical grid in the north polar region are investigated by comparing simulations performed on two curvilinear grids with one performed on a latitude-longitude grid and by comparing filtered and unfiltered latitude-longitude simulations. Resolution of horizontally separated currents in Fram Strait emerges as a key challenge for representing exchanges with the Arctic in global models. It is shown that a global curvilinear grid with variable resolution is an efficient way of providing a high density of grid points in a particular region. In equilibrium experiments using asynchronous time steps, this type of grid has been found to allow a better representation of smaller-scale features in the high-resolution region while maintaining contact with the rest of the World Ocean, provided that lateral mixing coefficients be scaled with grid size so as to maintain marginal numerical stability. In this study, the region of interest is the southern Indian Ocean and, in particular, that of the South Indian Ocean Current. In all experiments, decreased viscosities and diffusivities were found to control tracer gradients on isopycnals but not isopycnal slopes, while thickness diffusivities controlled isopycnal slopes but only to a small degree tracer gradients. Changes to mixing coefficients in the coarse part of the grid had hardly any influence on the frontal properties examined, although they did affect currents in the Indian Ocean to some extent via their control on size of the Antarctic Circumpolar Current and the Pacific-Indian Throughflow.
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From the parent record held in the GCMD: The data sets in the CDC archive called "Reynolds SST' and "Reconstructed Reynolds SST" were discontinued on 1 April 2003. A new OI SST data set is available as described here, which includes a new analysis for the historical data and updates into the future. NCEP will not provide new data for the "Reynolds SST" after December 2002 and CDC will remove the "Reynolds SST" data set on 1 April 2003. TO SEE THE NEW DATASET, PLEASE SEARCH THE GLOBAL CHANGE MASTER DIRECTORY FOR MORE INFORMATION. REFER TO THE METADATA RECORD (LINKED BELOW): REYNOLDS_SST ############# This metadata record is a modified child record of an original parent record registered at the Global Change Master Directory. (The Entry ID of the parent record is REYNOLDS_SST, and can be found on the GCMD website - see the provided URL). The data described here are a subset of the original dataset. This metadata record has been created for the express use of Australian Government Antarctic Division employees. Reproduced from: http://www.emc.ncep.noaa.gov/research/cmb/sst_analysis/ Analysis Description and Recent Reanalysis The optimum interpolation (OI) sea surface temperature (SST) analysis is produced weekly on a one-degree grid. The analysis uses in situ and satellite SSTs plus SSTs simulated by sea ice cover. Before the analysis is computed, the satellite data are adjusted for biases using the method of Reynolds (1988) and Reynolds and Marsico (1993). A description of the OI analysis can be found in Reynolds and Smith (1994). The bias correction improves the large scale accuracy of the OI. In November 2001, the OI fields were recomputed for late 1981 onward. The new version will be referred to as OI.v2. The most significant change for the OI.v2 is the improved simulation of SST obs from sea ice data following a technique developed at the UK Met Office. This change has reduced biases in the OI SST at higher latitudes. Also, the update and extension of COADS has provided us with improved ship data coverage through 1997, reducing the residual satellite biases in otherwise data sparse regions. The data are available in the following formats: Net CDF Flat binary files Text