Vertical Electric Field data from Concordia Station - 2009 - 2012

Full description

Vertical Electric field measurements captured at Concordia Station. The files are stored in XML format, and contain detailed headings describing the data layout and format. The data are collected by a rotating electric field mill mounted on an all metal mast. The EFM is ~3m off the ground.

The vertical electric field measurements collected at the French (IPEV) and Italian (PNRA) station at Concordia are approved under the project: Electricite Atmospherique DC 33 N.

Data collection was commenced in January 2009 and concluded in January 2012.

Unlike the Vostok equipment (which is similar), the Concordia electric field mill was not calibrated after installation. Experience at Vostok indicates this equipment is relatively stable (see the Vostok data and the post-2006 calibrations if you need to quantify the term 'relatively stable'. As a rough estimate, dividing the 'raw' value by 10,000 yields an value approximately equal to the 'volts per metre', positive downward, relative to the calibration box (which is what both the Vostok and Concordia electric field mills are calibrated against). The instrument compression is not noted but is significantly greater for the earlier era instrument (operating at Vostok between 1998 and 2004), principally but not exclusively due to the different heights of the mill. As a better estimate of the values relative to the 'calibration box' use: Ez (relative to calibration box) = Raw Value * 1.019/10000 -2.2 [in volts per metre relative to the calibration box].

Gary Burns is working on a 'fair weather' selection of the Concordia data, and a comparison with coincident vertical electric field measurements at Vostok.


Public Summary of the project:
We are investigating a poorly understood meteorological process with both internal (thunderstorms and electrified clouds) and external (space weather/cosmic ray) inputs having weather and climate implications. We have recently shown that a small but statistically significant sun-weather linkage occurs via the atmospheric electric circuit and that the linkage mechanism has an appropriately enhanced meteorological response associated with distant but more dominant generators of this circuit. The process has both natural (variations in cosmic rays; electrical meteorological climate variations may have a modified influence on global climate by this process) and anthropogenic (via global warming) climate implications.

Public summary of the season progress:
Electric field data were collected at Vostok and Concordia on the Antarctic Plateau to measure the atmospheric circuit. We have quantified the local contributions (solar wind and local meteorology) to the Vostok measurements. The solar wind contribution dominates over the local meteorology, confirming that the Vostok measurements largely measure a global signal of electrical meteorological convective activity (expected to increase due to anthropogenic climate change). Minor but statistically significant seasonal influences due to local temperature and wind have been quantified.

Lineage

Progress Code: completed

Statement: The data are calibrated only against a set of parallel plates mounted in a Faraday box which was placed over the electric field mill. This means that no account has been taken of the compression of the electric field by the metal support. The data should be viewed as relative values. Unlike Vostok, where the EFM is calibrated each month, we were satisfied that the new EFM MarkIII was broadly stable with-respect-to its calibration [We cannot be certain if the small annual variation in calibration seen in the Vostok monthly calibrations is due to temperature influences on the calibration box, or true variations in the response of the EFM]. For the Concordia data, to transform the raw data, please use the following: V/m = 1.014*[(Raw Counts/10000) -2.9] ...BUT note that these are still values relative to the calibration box NOT absolute values.