ESRI grids showing sea salinity, linearly interpolated from CARS2000 mean and seasonal fields to 0.1 degree spaced grid, at depths of 0, 150, 500, 1000 and 2000 metres. The loess filter used to create CARS2000 resolves at each point a mean value and a sinusoid with 1 year period (and in some cases a 6 month period sinusoid - the "semi-annual cycle".) The provided "annual amplitude" is simply the magnitude of that annual sinusoid. CARS is a set of seasonal maps of temperature, salinity, dissolved oxygen, nitrate, phosphate and silicate, generated using Loess mapping from all available oceanographic data in the region. It covers the region 100-200E, 50-0S, on a 0.5 degree grid, and on 56 standard depth levels. Higher resolution versions are also available for the Australian continental shelf. The data was obtained from the World Ocean Atlas 98 and CSIRO Marine and NIWA archives. It was designed to improve on the Levitus WOA98 Atlas, in the Australian region. CARS2000 is derived from ocean cast data, which is always measured above the sea floor. However, for properties which do not change rapidly near the sea floor, this would not lead to a significant error. All the limitations of CARS2000 also apply here.

Algorithms are presented for density, potential temperature, conservative temperature, and the freezing temperature of seawater. The algorithms for potential temperature and density (in terms of potential temperature) are updates to routines recently published by McDougall et al., while the algorithms involving conservative temperature and the freezing temperatures of seawater are new. The McDougall et al. algorithms were based on the thermodynamic potential of Feistel and Hagen; the algorithms in this study are all based on the "new extended Gibbs thermodynamic potential of seawater" of Feistel. The algorithm for the computation of density in terms of salinity, pressure, and conservative temperature produces errors in density and in the corresponding thermal expansion coefficient of the same order as errors for the density equation using potential temperature, both being twice as accurate as the International Equation of State when compared with Feistel's new equation of state. An inverse function relating potential temperature to conservative temperature is also provided. The difference between practical salinity and absolute salinity is discussed, and it is shown that the present practice of essentially ignoring the difference between these two different salinities is unlikely to cause significant errors in ocean models.

The neutral density code comes as a package of MATLAB and/or FORTRAN routines which enable the user to fit neutral density surfaces to arbitrary hydrographic data. The FORTRAN implementation consists of a FORTRAN subroutine which labels a cast of hydrographic data with neutral density, and another subroutine which then finds the positions of specified neutral density surfaces within the water column. The MATLAB implementation consists of two MATLAB functions performing these same operations, only on sections of hydrographic data. Versions are available for Unix workstations running with the NETCDF data archiving library and PC's not running NETCDF. This latter code is suitable for compilation on Unix workstations or other machines not running the NETCDF library. The MATLAB version for the PC does not require compilation of the underlying FORTRAN code, unlike the UNIX version of the code. All code comes with documentation in the form of Readme files, as well as Makefiles and examples to provide check values for the user. This "in-house" CSIRO software is available under conditions which are attached with the software.

This dataset contains the processed Conductivity-Temperature-Depth (CTD) data collected on Maritime Image voyage MI200201, processed by SRFME staff and is archived within the CSIRO Marine and Atmospheric Research Data Centre in Floreat. This dataset is part of the SRFME research program.