1. Australian Antarctic Data Centre
2. Discover and Manage Data
3. Records
4. AAS_4130

Description

A long-standing problem is why the mid-latitude ionosphere (e.g. over Australia) is sometimes enhanced during space weather storms, and sometimes depleted. While storms occur mainly at high latitudes, their effects propagate equatorward via upper atmosphere's winds, waves, electric fields, and chemical composition but we do not understand why the relative importance of these varies from storm to storm. By measuring these various drivers over Antarctica and their subsequent impacts at mid-latitude during many storms over a 5-year period we will determine the statistical importance of each driver.

The spectrometers are currently based at Mawson and Davis. This record details thermospheric and mesospheric winds, temperatures, and emission intensities from the Fabry Perot Spectrometer.

This project has replaced ASAC project 2699 - the data from which are held in the metadata record "Fabry-Perot_Spectrometer".

Quality

A pair of files is generated for each observation, a JPG file which is a photograph of interference fringes, and a SPECS file that contains information about the observation. SPECS files are binary files so they can only be read by a program designed to read them.

Attached is a file containing a program that will open SPECS files. Please change the file extension from 'tmp' to 'exe'. Operation of the program is hopefully reasonably intuitive. Select the required folder then click on the file that you want to open. A screen shot is also attached.

Information about the observation is at the top of the screen from left to right as follows:

- 'psm' then the time in seconds that the spectrometer took to move it's periscope and point it at the appropriate part of the sky.
- The direction of observation. In the screen shot the direction is "Mawson cv" meaning that the spectrometer was looking at the common volume of sky between Davis and Mawson.
- Following "IS" the optimum exposure time in seconds (given to the nearest whole number) that the computer has calculated.
- UT time of the observation.
- Date of the observation.

In the top right hand corner are listed:
- Coordinates in pixels of the centre of the fringe pattern used in calculations.
- An estimate of the actual exposure time.
- The angle of elevation above the horizon of the field of view i.e. the elevation of the periscope.

The top plot shows the shape of the spectra derived from interference fringes. The vertical axis is approximately proportional to intensity and the horizontal axis gives an indication of changing wavelength. The red plot is raw data and the green plot is raw data minus an estimate of system noise.

The lower plot shows approximate intensity as a function of fringe radius.

These plots are used only as a diagnostic tool to check that the instrument is working properly they are not used for scientific analysis of the data.

A copy of the software used to read the SPECS files is also available with the data.

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Note that the provided dataset is incomplete. Contact with the investigator was lost and only part of the dataset from the AAP project was archived.

Access

These data are publicly available for download from the provided URL.

Temporal Coverages

• Start date: 2012-07-01 - Stop date: 2013-10-31

Spatial Coverages

Science Keywords

• EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC TEMPERATURE > SURFACE TEMPERATURE > AIR TEMPERATURE
• EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > UPPER LEVEL WINDS

Use Constraints

This data set conforms to the CCBY Attribution License
(http://creativecommons.org/licenses/by/4.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=AAS_4130 when using these data.