ELECTRICAL EFFECTS that may HAPPEN in ICE CLOUD-NEW SCIENTIST

The MICRO-WORLD in the THUNDERSTORM

ELECTRICAL EFFECTS
that may HAPPEN in ICE CLOUD

NEW SCIENTIST and SCIENCE JOURNAL
VOL.51, NO.765, AUGUST 1971

Roger J. CHENG
Atmospheric Sciences Research Center, SUNY-ALBANY

雷暴云中的起电过程

● 带正电的微液滴是经由来自于冻滴霜结表面过冷却云滴的冰冻过程形成的，而非传统认为的力学的压裂、碎裂、碰撞生成，期间总是伴随著带负电的冰晶碎片的射出、成长过程中曲率效应控制的凝华。

● 显微观测到的散落液滴破碎过程中伴生的荷电现象揭示了雷暴云中冰晶繁生与起电的快速冰化机理（基于热学电学效应，Workman & Reynolds-1950）。

纽约州立大学，大气科学研究中心郑均华研究员主持的科研项目

"THUNDERSTORM ELECTRIFICATION"

● Micro-droplets(+) are generated by the freezing of a super cooled water drop, which is followed by the ejection of electric charged(-) ice fragments, by sublimation governed by curvature effect in a state of growth. (rather than by mechanical fracturing, splintering & collision), from frosty surface of the frozen drop. (ice pellet).

● This observed microscopic phenomenon of fragmentation of hydrometeors with their accompanying electrical charges suggests a mechanism of rapid glaciations of ice multiplication process and electrification in a thundercloud.
(based on: Thermo-Electric Effect-Workman & Reynolds-1950)

The MICRO-WORLD

in the THUNDERSTORM

HOME

ATMOSPHERIC

SCIENCES

SNOW and ICE

CLOUD SEEDING

FREEZING

of A WATER DROP

FRAGMENTATION

of A FROZEN DROP

MELTING of

A FROZEN DROP

CHARGE within

An ICE CRYSTAL

PUBLICATION

and CITATION

The exact mechanism of thunderstorm electrification and the glaciations processes in ice clouds that lead up to it. Remain elusive. Earlier this year Monitor reported some work showing how freezing super cooled drops eject tiny positively charged droplets to produce primary electric charge separation (see New Scientist. viol 49. p 54-1970), Roger Cheng who discovered this effect, and his colleague Vincent Schemer at the State University of New York. Have now pointed out some related effects in the growth of ice crystals which may account for the observed very rapid glaciations process that typifies certain types of super cooled concessive clouds (Journal de Recherché Atmosphéngues. vol V. no I.-1971).

Such clouds often cause thunderstorms and blizzards. In the laboratory it is possible to generate the kind of small ice crystals seen in Figure d, which closely resemble those found by sampling actual clouds of this type, by forming a layer of frost on a cold piece of ice. Schaefer and Cheng say the effect can be demonstrated by putting some dry ice into a polythene bag and sticking the bag in warm air. The bag soon becomes coated with a dust-like frost layer which grows and eventually sprouts minute tree-like growths of ice crystals. Under a low-power microscope these particles arc seen to be intensely mobile, twisting and writing, breaking off from the surface, and sometimes exploding into masses of even smaller fragments. the photograph shows, the ice particles are often very tenuously attached to the surface. It seems obvious that their motions must be a response to static electrical forces.

The two cloud physicists propose that a similar mechanism is at work on the surfaces of hailstones which form in Convective clouds at an early stage when there are plenty of droplets and moisture for their growth. As they get larger they fall into regions of warmer air which, if it is super-saturated. Coats them with a delicate layer of frost. The disintegration of the frost particles leads to further nuclei for the development of new ice crystals. Thus providing a chain reaction of glaciations. Figure C shows an experimental hailstone-in a moist environment repelling frost particles electrically from ice dendrites. Under the microscope the ice particles can be seen to move vigorously in response to an electrically charged object. The stems” of the ‘trees” are, in many cases. Very thin (often less than five micrometers) that they would be expected to evaporate easily, adding to the fragility of this frost layer. And. In fact, Schaefer and Cheng have observed progressive thinning of the particle’s attachments in this manner.

Cheng recently wrote to Monitor pointing out that their team has now determined that the ejected ice particles from frosty surfaces mostly carry negative electrical charges. Presumably leaving the surface in question with a net positive charge. Once a basic charge-separation mechanism of this kind has been proven it becomes possible to suggest means by which larger and smaller components are physically separated and thus build up the high voltages characteristic of thunder clouds. It appears that protons travel more easily through ice and tend to congregate at the colder parts. In Cheng’s earlier experiment the warmer water droplets were positively charged and the residual freezing parent drop negatively charged. On disintegrating frosty surfaces this situation is apparently reversed.

Another later discovery is that ejected ice fragments certainly can be grown to produce perfect ice crystals.

COMMENTS on THUNDERBOLT PROJECT

A microscopic study on physical processes

of precipitations in a thundercloud

their nucleation, fragmentation and electrification,

by Roger J. CHENG
Atmospheric Sciences Research Center, SUNY-ALBANY

1. LONDON TIMES, London, England, Jan. 4, 1971-Science Report-WEATHER,
“How Lightning May be Produced,”
.... .the observation of this separation process may therefore be the prime factor in the generation of thunderstorm electricity....”
2. ANN ARBOR NEWS, Jan. 31, 1971-The Science Beat, “Causes Lightning?”
. . .A. D. Moore, University of Michigan, Professor Emeritus of Electrical Engineering, and one of the world’s foremost authorities on electrostatics, says what could be the big ‘breakthrough’ in knowledge of what causes electrical discharges during thunder storms..... .the best explanation yet of the electrical discharges we hear as thunder and see as lightning...”
3. NEW SCIENTIST, London, England, Vol. 734, Jan. 1971. “
. . .Recent observation by Roger Cheng of the University of New York reveals a fascinating new microscopic process which almost certainly has an important bearing on how thunderclouds become charged to their high voltages....”
4. SUMMARY REPORT WEATHER MODIFICATION, Fiscal Year 1972,
by US Dept. of Commerce, National Oceanic & Atmospheric Administration
from chapter Cloud Electricity and Lightning Modification, “.....investigators from the State University of New York at Albany (Cheng, 1970) have been studying the freezing of super cooled water drops. suggestion that this mechanism might be important in the generation of thunderstorm electricity....”
5. Dr. J. V. Iribame, University of Toronto, Canada,
..... I believe that separation of liquid droplets, rather than ice splinters, may be a basic process causing electrification during riming of super cooled droplet....”
6. Dr. Herbert A. Phol, University of Cambridge, England,
.... .it opens up several new pathways. .1 am citing your work in my chapter in A.D. Moore’s forthcoming book on Electrostatics....”
7. Dr. Senichi Masuda, Chairman, Dept. of Electrical Engineering, University of Tokyo, Japan,
.... .1 would like to use the photomicrograph related to your article in SCIENCE, ..'Water Drop Freezing: Ejection of Microdroplets' in my book, “MODERN APPLIED ELECTROSTATICS”.
8. Dr. Leonard B. Loeb, Professor of Physics, University of California, Berkeley, “
... it could well be that this is one of the main sources of thunderstorm electrification—
especially since it has been shown that B.J. Mason’s splintering theory has proven inadequate.., you have made a most interesting discovery.
9. Dr. C. L. Andrews, Professor of Physics, SUNYA,
..... it is the most beautiful combination of mechanics, thermodynamics, electricity and magnetism and optics... you have initiated a field worthy of a few lifetimes of study...
10. Britanica Yearbook of Science and the Future, 1973, BRITANICA ENCYCLOPEDIA,
from Review of Atmospheric Science, by Dr. L. J. Battan, Professor of Atmospheric Science,
Director of the Institute of Atmospheric Physics, University of Arizona,
.... .this separation mechanism could possibly generate lightning in storm clouds...
11. The World Book Science Annual 1974, SCIENCE YEAR from Science Report “The New Rainmaker”
by Dr. C. L. Hosler, Dean, College of Earth & Mineral Sciences, Penn State University, “
...tiny particles of ice break off..., and scattering electrically charged micro-droplets..., such studies help explain rapid changes in the cloud...”
12. Dr. Choji Magono, Professor, Geophysical Sciences, Hokkaido University, Japan,
Chairman: Section of Ice and Snow Crystals, International Conference on Cloud Physics, 1968 in his keynote paper at the conference, .... .Cheng (1967) observed many clumped ice crystals and considered that the clumping was caused by Coulomb force. The author also observed clumped ice crystals...and found that the clumping seemed to occur under a microscope by Coulomb force...”
13. From “Aggregation Phenomena of Ice Crystals,” Journal of the Meteorological Society of Japan,
Vol. 50, No. 5, October, 1972, “......it is noted.. .that the ice crystals observed were in a state of growth in which the charge separation could occur within an ice crystal, as pointed out by Cheng (1967).”