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.

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Russia Vessel: Mikhail Somov Dates in ice: 28 Feb 1984 - 17 Mar 1984 Observers: Unknown Translation to ASPeCt data format: Vladimir Smirnov Summary of voyage track: 28/2 Ice edge at approx. 72S, 144W 28/2-2/3 Ice edge to Russkaya (136W) 3-11/3 At Russkaya (no observations) 12-17/3 Russkaya to ice edge edge at approx. 68S, 132W There were substantial periods of drift in very heavy ice during this voyage. The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data are in the ASPeCt format. National program: Russia Vessel: Akademic Fedorov Dates in ice: 06 Jan 1993 - 03 Feb 1993 Observers: Unknown Translation to ASPeCt data format: Vladimir Smirnov Summary of voyage track: 6/1 Ice edge at approx. 63S, 80E 6-8/1 From ice edge to Mirny (93E) 12-18/1 From Mirny to Dumont d'Urville (140E) 18-20/1 From DD to Leningradskaya (159E) 21-23/1 From Leningradskaya to McMurdo (168E) 29/1-1/2 From McMurdo to Russkaya (136W) 1-3/2 From Russkaya to Bellingshausen (59W) No observations after Bellingshausen The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Aurora Australis Dates in ice: 05 Nov 1998 - 18 Dec 1998 Observers: Matt Paget Summary of voyage track: 5/11 Ice edge at approx. 60S, 113E 5-7/11 Ice edge to Casey 8-18/11 Casey to Davis (conducting survey of pack ice seals) 22-23/11 From Davis west to 74E 24-26/11 No obs - flying operations 27-30/11 Vicinity of 74E 1-12/11 No obs - ship stopped in ice due to propeller damage 13-18/2 Towed to ice edge by Shirase, ice obs conducted. The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Nathaniel B. Palmer Dates in ice: 10 Sep 2001 - 22 Oct 2001 Observers: Rob Massom and others Summary of voyage track: 10/9/01 First brash ice 11-20/9/01 Transect from vicinity of Palmer to Rothera 22/9/01 - 21/10/01 Marguerite Bay and out to ice edge 21/10/01 Ice edge at 67'18.55S 71'29.49W 22/10/01 Transect parallel to ice edge to vicinity of Palmer The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Russia Vessel: Mikhail Somov Dates in ice: 28 Feb 1986 - 16 Mar 1986 Observers: Unknown Translation to ASPeCt data format: Vladimir Smirnov Summary of voyage track: 28/2 Ice edge at approx. 69S, 139W 28/2-6/3 In company with vessel 'Kapitan Bondanernko' to approx. 72S, 140W 7-8/3 Independent navigation to Russkaya 14-16/3 Russkaya to ice edge at approx. 68S, 151W The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Russia Vessel: Akademic Fedorov Dates in ice: 12 Mar 1990 - 31 Mar 1990 Observers: Unknown Translation to ASPeCt data format: Vladimir Smirnov Summary of voyage track: 12/3 Ice edge at approx. 70S, 131W 12-17/3 Steamed west as far as 74S, 175W 17-26/3 Steamed east to 75S, 149W 27-28/3 No observations. In company with Mikhail Somov 29-31/3 From 75S, 176W to 67S, 162W The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Russia Vessel: Akademic Fedorov Dates in ice: 22 May 1997 - 24 Jul 1997 Observers: Unknown Translation to ASPeCt data format: Vladimir Smirnov Summary of voyage track: 22/5 Ice edge at approx. 66S, 14E 22-23/5 From ice edge to Novolazarevskaya (12E) 29/5-10/6 Novolazarevskaya to Mirny (93E) 18-28/6 Mirny to Druzhnaya (74E) 7-16/7 Druzhnaya to Molodezhnaya (46E) 17-21/7 Molodezhnaya to Novolazarevskaya 22-24/7 Novolazarevskaya to ice edge at approx. 60S, 20E The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

On every voyage of the Aurora Australis, approximately 50 onboard sensors collect data on average every 10 seconds. These data are known as the underway datasets. The type of data collected include water and air temperature, wind speeds, ship speed and location, humidity, fluorescence, salinity and so on. For the full list of available data types, see the website. These data are broadcast "live" (every 30 minutes) back to Australia and are available via the Australian Oceanographic Data Centre's portal (see the provided link). Once the ship returns to port, the data are then transferred to Australian Antarctic Division servers where they are then made available via the Marine Science Data Search system (see the provided URL). This dataset contains the underway data collected during Voyage 2 of the Aurora Australis Voyage in the 2019/20 season. Purpose of voyage: Casey Resupply, recover and deploy whale mooring. Leader: Mr. James Moloney Deputy Leader: Miss Anthea Fisher VM Trainee: Ms Gemma Dyke Underway (meteorological) data are available online via the Australian Antarctic Division Data Centre web page (or via the Related URL section).

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: United States Vessel: Nathaniel B. Palmer Dates in ice: 26 Dec 1999 - 06 Feb 2000 Observers: Steve Ackley, Jackie Ackley, others Summary of voyage track: 26/12 Ice edge at approx. 67S, 180 26/12 - 14/1 Complicated cruise track through the Ross Sea toward SE then NE to 128W 14/1 - 6/2 Back through pack ice toward the west 6/2 Obs completed at Cape Colbeck (157W) The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER HH:MM:SS VISIBILITY CODE CLOUD IN OKTAS WEATHER CODE COMMENTS