Glenn Elert
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The Physics Factbook™
Edited by Glenn Elert -- Written by his students
An educational, Fair Use website
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| Bibliographic Entry | Result (w/surrounding text) | Standardized Result |
|---|---|---|
| Cutnell & Johnson. Physics.New York: Wiley, 1995: 583. | "One day the electric field in the atmosphere near ground level is 110 N/C" | 110 N/C |
| Giancoli, Douglas C. Physics, Principles with Applications. 3rd ed. Englewood Cliffs, NJ: Prentice Hall, 1991: 439. | "Measurements indicate the presence of an electric field surrounding the Earth. Its magnitude is about 150 N/C at the earth's surface." | 150 N/C |
| Handbook of Chemistry and Physics. 61 ed. Florida: CRC Press, 1980-81: F-214. | "Volume element at about sea level: E = 1.2 × 102 V/m Volume element at about 2 km height: E = 6.6 × 101 V/m" | 120 N/C 66 N/C |
| Merrill Physics: Principles and Problems. New York: Glencoe, 1995: 444. | "The electric field in the atmosphere is about 150 N/C, downward" | 150 N/C |
| Landa, Judah. How to Study Physics. New York: Jay-El, 1995: 209. | "Near the surface of the earth there exists an electric field whose intensity is 100 N/C directed downward" | 100 N/C |
The electric field is a measure of the force that is exertedper coulomb of charge. Its measure is defined as kq/r2where k is the electrostatic constant constant, q is the amountof charge, and r is the distance between charges. The presenceof an electric field is identified using a test charge.
The earth's atmosphere has an electric field that is directedradially inward. Most of my sources show that knowing the electricfield of the earth can lead to the calculation of the charge onthe earth's surface. Though some of the figures obtained are forthe earth's atmosphere, it is true that the magnitude of the electricfield outside a uniformly charged sphere is the same as if allthe charge were concentrated at the center.
I obtained values for the magnitude of the electric field atthe Earth's surface. These were in the range of 66 N/C to150 N/C. These values are close enough to assume that eachsource received their data from a different primary source andeach may be accurate in their own right. I am convinced that thefigure is closer to 150 N/C than to 66 N/C because ofthe sources themselves.
Though the electric field is reported as being constant bysome of my sources, The Handbook of Physics and Chemistryproves that the electric field intensity varies measurements takenat different altitudes above sea level. Its intensity decreasesas you move farther away from the earth's surface.
Tresha Edwards -- 1998
| Bibliographic Entry | Result (w/surrounding text) |
Standardized Result |
|---|---|---|
| Atmospheric Electricity. Grupo de Eletricidade Atmosférica (ELAT). Instituto Nacional de Pesquisas Espaciais. June 2005. | "Over land the average electric field is about 120 V/m …. Assuming an exponential increase of the conductivity with altitude, it can be shown that the electric field decreases exponentially with altitude. At the 30-km level, the electric field is as low as 300 MV/m [sic]. Integrating the electric field from the earth's surface to the ionosphere gives as a result an electric potential difference of about 200 kV." | 0.300–120 V/m |
Editor's Supplement -- 2005
| Another quality webpage by Glenn Elert |
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