4 ms·
> googling [...] drew a blank Global atmospheric electric circuit; atmospheric electric field (or potential gradient); Carnegie curve; electric field mill sens
by mncharity 6y ago
> googling [...] drew a blank
Global atmospheric electric circuit; atmospheric electric field (or potential gradient); Carnegie curve; electric field mill sensor.
> those numbers
It varies a lot. Time of day, location, conditions. Perhaps usually more than -100 V/m, and less than 200 V/m or so?
Nothing compared to the 10 kV of zapping doorknobs in winter.
> never seen [in...] buildings'
The e-field contours follow the outside of a building, rather than cutting through it. And of a person. And more inconveniently, sometimes of a sensor pole.
It's long seemed to me a pity this isn't used more in intro physics E&M. Been known for one or two+ centuries. Maybe with drone-sized less-expensive e-field sensors it will get more visibility?
- Pick-A-Hill2019 6y agoHave an upvote for the rabbit hole although I still don't see any solid evidence backing up the 100v per metre claim unless scaled to ground vs. a theoretical probe placed 5+ kilometres up in the clouds.
- mncharity 6y agoYou can watch it live[1] at UK Reading's Atmospheric Observatory. Currently (00-ish UTC), the last 12-ish hours there, have been between 100 and 150 V/m. Preceded by 6-ish hours of high-variability, say -50 to 100 with excursions down by -200 V/m. And then 6-ish hours of 50 to 100 V/m. Aside from the 6 hrs of variability, which look like a front coming in, the shape seems stereotypical Carnegie curve. [1] http://www.met.reading.ac.uk/weatherdata/Reading_daily_AWS_graphs.html#8 http://www.met.reading.ac.uk/weatherdata/Reading_daily_AWS_g...
- BlueTemplar 6y agoRight, the voltage is huge compared to household electronics, however the amperage is tiny...