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This workshop discusses the challenges and progress in monitoring the global electrical circuit from land stations in Antarctica, with a focus on the measurement of electric fields and their correlation with surface air temperature.
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Five Special Days at Vostok and Concordia (Antarctica) Earle Williams and Anirban Guha Gary Burns and Brian Tinsley Workshop on the Global Electric Circuit Mitzpe Ramon, Israel February 6-9, 2017
Monitoring the Global Electrical Circuit from Land Stations For the most part, this endeavor has been a history of failure Reasons: Pollution/space charge in continental boundary layer Convective overturn of the boundary layer Variable conductivity In short: No stable medium for monitoring
Improvements in Antarctica Pros: Stable medium Two-station comparisons Cons: Katabatic winds Blowing ice and snow Electrode effect Progress: Burns et al. (2005, 2012) Kniveton et al. (2008)
Rutledge and Carey on Bathurst Is. for MCTEX in 1995 The study of “Hector”
Five Special Days at Vostok and Concordia Stacked plots of electric field measurements at Vostok and Concordia for five consecutive days in March 2009. (Burns et al., 2017)
Why should the current source for the global circuit follow surface air temperature? • In all climates, water vapor increases with increasing temperature (Clausius-Clapeyron relationship) + 7% per degree C at 0°C • In the present climate, Convective Available Potential Energy (CAPE) increases with temperature • In a warmer climate, CAPE is predicted to scale with Clausius-Clapeyron (Romps, 2016) Vapor Pressure Temperature (°C)
Access to global temperature on short time scales • For global climate studies, monthly means are the norm • For global reanalysis, surface temperature measurements are generally not ingested • For surface skin temperature and MSU observations, satellite sampling from LEO is inadequate for global hourly analysis
Stations available for surface air temperature measurement on March 5, 2009
Number of surface stations involved in the global averaging over five days
Global temperature variation for five special days (March 5-9, 2009)
Electric field at Vostok and Concordia and global temperature for five special days Stacked plots of electric field measurements at Vostok and Concordia for five consecutive days in March 2009. 3-hourly global temperature variation.
Conclusions • Globally representative measurements of the DC global circuit can be achieved in Antarctica • Calculation of global mean temperature is facilitated by access to all quality-checked surface thermometers at • 3-hourly time scales • The DC global circuit is responsive to temperature on both the diurnal time scale and the five day time scale • In five days the mean global temperature can increase by the same amount (~1C) it has increased in a century in global warming