The Global Electrical Circuit: A Review

Earle WilliamsMIT

International Conference on Atmospheric Electricity Beijing, China

August 2007

Outline - Global Circuit

The two Global Circuits : How are they different?

Carnegie Curve vs Thunder Area

Robustness of Carnegie Curve for individual days

Effects of Bomb tests in the 50s and 60s

Long-term variations

Response of global circuit to global change

Two Versions of the Global Circuit

Classical Analysis of the Global Electrical Circuit

Carnegie Curve

Thunder Area

Wilson (1920)

"Thunderclouds and shower clouds"

are the sources for the global current.

A common Assertion: Thunderstorms are the batteries for the Global Circuit

Wallace et Hobbs (1977)

Williams ( 1988)

Blakeslee et al (1989)

Vonnegut (1991)

Bering et al (1998)

Rycroft at al (2000)

Reddell et al (2004)

Holzworth et al (2005)

Hayakawa et al (2006)

Kartalev et al (2005)

Nickolaenko et al (2006)

WILSON (1920) DID NOT MAKE THIS CLAIM

Distinctions in the two Global Circuits

The Global Balance Sheet(at Earth’s surface)

Fine Weather Current + 60 C

Precipitation + 30 C

Lightning - 20 C

Point Discharge - 100 C

Wormell (1930,1953)

Vertical continuity of current

Global Lightning is more Volatile than the DC Global Circuit

Carnegie Curve OTD Analysis

OTD Analysis

Diurnal Time Scale

Ionospheric Potential

Annual Time Scale

Two hypotheses for American Dominance over Africa in the Carnegie Curve

1) Current control by position of magnetic dip

equator (Kartalev et al, 2006).

2) Electrified shower curves in South America

dominate over Africa.

Measurements (Burns et al, 2005) and Predictions (Kartalev et al, 2006)

for Seasonal Variations in the Carnegie Curve

African Lightning Exceeds South American Lightning

Williams and Sátori (2004)

Carnegie Curve on Individual Days ?

Ralph Markson : We should get the get the

same result every day.

Bob Holzworth : We can have factor-of-two

fluctuations from one

day to the next.

Diurnal Variations of Ionospheric Potential

Note similarity with behavior of ‘carnegie curve’

(Markson et al, 1999)

Simultaneously Recorded Electric Field at Two Widely Separated Locations

Holzworth et al (1984)

Electric Field at South Pole Observatory

(Reddell et al, 2004)

Schumann Resonance Diurnal Variations HEW

Schumann Resonance Diurnal Variations HNS

Impact of nuclear weapons

testing on Atmospheric

Electicity

Long-Term Variations in Electric Field at Two Sites in England

1955 1966

1955 1966

Global Impact of Radioactive Fallout

Ionospheric Potential and Stratospheric Burden of Radioactive Strontium

Long-Term Variations of

Global Current

Downward Trends at Nagycenk (Hungary) and Eskdalemuir (UK)

Harrison (2003)

Märcz and Harrison (2003)

Evidence for Reduced Pollution in the UK in the 20th Century

McIntosh (1957) Decline in smoke concentration

at

Eskdalemuir

Novakov et al (2003) Decline in black soot production

from 1920 onward

Reduced Pollution Enhanced Conductivity

Reduced Electric Field

14 Years of Schumann Resonance Intensity

Stability of Electric Field at Kennedy Space Center

(Halstead Harrison, GRL 2006)

Air Earth current record at Kew

Air–earth current measurements at Kew, London, 1909–1979R.G. Harrison,T, W.J. Ingramb.  Atmospheric Research 76 (2005) 49–64

From Harrison and Ingram, 2005

Long-Term Variation of Ionospheric Potential

Global circuit response

to Global warming?

Global Warming is Sensitive to Latitude

Anticipated Response of Global Circuit to Global Warming

Anticipated sensitivity 10% per 1°C

Measured global warming (tropics) 0.1°c per decade

Anticipated rate of increase 1% per decade

This may go undetected in a short record

Temperature and Thunder Days, Fairbanks, AK

1950 1960 1970 1980 1990 2000 20100

5

10

15

20

Nu

mb

er o

fT

hu

nd

er D

ays

Tem

per

atu

re (

°F)

52

54

56

58

60

62Summer Average Temperatures,Fairbanks, AK 1950 - 2005

Summer Thunder Days,Fairbanks, AK

CONCLUSIONS The ‘DC’ and ‘AC’ Global Circuits are correlated, but do not track

each other identically, for well established reasons.

Electrified shower clouds (Wilson, 1920) are fundamental in

understanding differences between the ‘DC’ and ‘AC’ Global

Circuits.

Nuclear weapons tests in the 1950-60’s appear to have had both

local and global effects on the Global Circuit.

No substantive evidence exists for a long-term decline in the

Global Circuit.

The absence of a clear upward trend in the Global Circuit is not

inconsistent with the documented upward trend in temperature.

Schumann Resonance Diurnal Variations HEW

Schumann Resonance Diurnal Variations HNS

Ionospheric Potential

Simpson’s (1905) Diurnal Variations in Lapland

0 2 4 6 8 10 12 14 16 18 20 22 UT

14 Years of Schumann Resonance Intensity

Simpson in Lapland 1904