PLEASE NOTE:
*
CCNet, 17 December 1999
-----------------------
QUOTE OF THE DAY
"The deplorable state of television
programming proves
that no advanced extraterrestrial
civilizations exist
in Earth's immediate vicinity, British
writer Sir
Arthur C. Clarke recently told a United
Nations
forum... Somewhat facetiously, he went
on to note that
since television signals continue to
radiate outward
from the Earth at the speed of light,
our televised
legacy now fills a sphere more than 100
light-years in
diameter. Since no alien police force
has yet arrived
to put an end to the nuisance, this
proves that no
advanced civilization occupies that vast
region, he
said."
-www.space.com/spaceimagined/clarke_un_tv_991124.html
(1) OBSERVED FIREBALL CAUSED BY RE-ENTRY OF CHINESE ROCKET
Josep Ma. Trigo i Rodriguez <jmtrigo@ctv.es>
(2) SEARCH PROJECT FAILS TO DETECT FRANK'S SMALL COMETS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(3) POSSIBLE METEORITE FALL IN DUNBOGAN
Gordon Garradd <loomberah@ozemail.com.au>
(4) ICE AGES, MILANKOVITCH & COSMIC DUST
Doug Keenan <Doug.Keenan@virgin.net>
(5) CLIMATE CYCLES & ASTRONOMICAL CYCLES
EXITE NEWS, 8 December 1999
(6) SUNLIGHT KEEPS COSMIC DUST AT BAY
ESA News Service, <sciweb@estec.esa.nl>
(7) EARTH REPORT 2000: MORE DOUBTS ABOUT GLOBAL WARMING
PROPHECIES
Competitive Enterprise Institute
(8) VOLCANIC ERUPTIONS & OZONE DEPLETION LEAD TO COOLING
OF ATMOSPHERE
Andrew Yee <ayee@nova.astro.utoronto.ca>
(9) METEORS & INTERPLANETARY DUST
Robert Hawkes <rhawkes@mta.ca>
(10) SNOWBALL EARTH
Michael Paine <mpaine@tpgi.com.au>
(11) AND FINALLY: CREATIONS, COLLISIONS & COMETS
Stephen Ashworth <sa@astronist.demon.co.uk>
===========
(1) OBSERVED FIREBALL CAUSED BY RE-ENTRY OF CHINESE ROCKET
From Josep Ma. Trigo i Rodriguez <jmtrigo@ctv.es>
Dear colleagues,
We are working in the reconstruction of the definitive 27th
Nov. fireball trajectory. Now our data are able to resolve
the nature of the incident object. As you can read below we
confirm finally from its trajectory and velocity that the
fireball was'nt produced by a meteoroid but by the re-entry
of the chinese Shenzhou Long March rocket (catalogued as
#25957=99-61B).
The fireball was really impressive and reached magnitude
-10 although it was variable depending of the observational
distance. A lot of people saw it as a silver fireball
followed by a reddish wake breaking into several pieces. It
appeared at 21h30m U.T. approx. on Jaen (Spain), overflew
the Balearic Islands, Corsica and it finished near Latium
(region of Rome) five minutes later. The trajectory has
been obtained from visual observations of several
eyewitness in Spain, Sardinia, Corsica and Italy. The
lenght of this trajectory was about 1.200 Km, only possible
from an incident object with a little angle inclination and
a low geocentric velocity i.e. a re-entry event.
The estimated velocity from our software was between 5-10
km/s that support the rocket hypothesis. We can hope for a
low orbit a velocity of 8 Km per second and about 150
seconds of flight. But probably they was one or two minutes
more due to the deceleration produced by the atmosphere.
The decay time for the Shenzhou Long March rocket (#25957 = 99-
61 B)
has been obtained from SatEvo analysis of the final elsets. The
calculation with this software send us by Manuel Montes-Palacio
predicts the re-entry at 20h30m UT approximately. Considering
minor
order effects in the rocket decay in the atmosphere and the drag
interaction, the 27th Nov. fireball was produced undoubtedly by
the
Shenzhou rocket.
A more detailed analysis, including video images recorded
by chance by a sailor will be send during the next month to
WGN, issue of the International Meteor Organization. We
modelize meteoroid trajectories and orbits but these
"artificial events" are interesting to us because they
gave
results on luminous efficiencies for big objects and
important data on the aerodynamics of the object entry in
the atmosphere. We will include in the WGN paper detailed
information on the trajectory and also on meteoroid orbits
obtained in 1999 from the East of Spain by the Spanish
Photographic Meteor Network (SPMN).
We appreciate enormously the great effort to obtain
additional data on the fireball to Enric Coll and Salvador
Sanchez (Observatori Astronomic de Mallorca), Alfonso
Lopez-Borgonoz (A.A.Castelldefels, Barcelona), Geoffrey
Cameron (Castelló), Roberto Gorelli (Italy), Manuel Montes
Palacio, Francisco Reyes and Juli Castellano-Roig (SOMYCE).
Finally, we are indebted to Drs. Zdenek Ceplecha, Pavel
Spurný and Jiri Borovicka (Ondrejov Observatory, European
Fireball Network) to make possible with their support our
Spanish Fireball Network.
Josep Ma. Trigo i Rodriguez
SPANISH FIREBALL NETWORK (SPMN)
-Dept. Astronomy & Astrophysics, Universitat de
Valencia
-SOMYCE
E-mails: jmtrigo@ctv.es / trigo@exp.uji.es
Web page: http://www.ctv.es/USERS/jmtrigo
Phones: (+Spain Code 34) 964 - 282584 /
282968 (office)
(964) 395064 (part.) Fax: 964 - 285161
Postal address: c/ Manuel de Falla 26,
12.560 Benicassim (Castello) SPAIN
============
(2) SEARCH PROJECT FAILS TO DETECT FRANK'S SMALL COMETS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
University News Services
University of Iowa
100 Old Public Library
Iowa City IA 52242
CONTACT: GARY GALLUZZO
e-mail: gary-galluzzo@uiowa.edu
(319) 384-0009; fax (319) 384-0024
Release: Dec. 16, 1999
UI researcher fails to detect small comets
IOWA CITY, Iowa -- University of Iowa astronomy professor
Robert Mutel announced today that an eight-month search
using an Arizona-based telescope has failed to detect
evidence supporting a 13-year-old theory that small comets
composed of snow are continually bombarding the Earth.
Mutel and co-author John Fix, professor of astronomy and
dean of the College of Science at the University of Alabama
in Huntsville, presented their findings at the annual
meeting of the American Geophysical Union (AGU) in San
Francisco. In their paper, they described their examination
of more than 2,700 photographic images taken with the Iowa
Robotic Observatory (IRO), located south of Tucson, Ariz.,
between Sept. 24, 1998 and June 11, 1999.
"We failed to find evidence that small comets exist,"
Mutel
said. "At the same time, no such search can entirely
disprove their existence. But if the small comets do exist,
they are present in far smaller numbers than previously
predicted."
The small comet theory, developed by fellow UI professor
Louis Frank and UI research scientist John Sigwarth, holds
that about 20 snow comets weighing 20 to 40 tons each
disintegrate in the Earth's atmosphere every minute. Frank,
an internationally known experimental space physicist,
defended the small comet theory in a paper published in the
Jan. 1, 1999 issue of the AGU Journal of Geophysical
Research-Space Physics. The paper described how a
mathematical formula was used to filter out instrument
noise, or static, from data gathered by NASA's Polar
satellite. The results showed that the dark spots, or
atmospheric holes, photographed by cameras aboard the Polar
satellite vary in size and number when photographed at
different times and at different altitudes. However, some
researchers continued to believe that the dark spots
appearing in the images are caused by instrument noise.
Mutel and Fix said that their search using the 20-inch IRO
reflector telescope was designed so that expected trails
would be easily seen without the need for elaborate
statistical analysis of faint trails. Observations were
made each month within one week of the new moon to maximize
sensitivity to faint objects. The computer-controlled IRO
telescope was used to produce multiple shuttered images to
distinguish cosmic ray tracks, sensor imperfections and
other artifacts from potential small comet trails. The
telescope searched for objects moving in the same direction
and orbital plane as the Earth at a distance of about
33,000 miles from the Earth.
Out of a total of 6,148 images made, 2,718 were suitable
for detection of object trails with magnitude 16.5 (about
10,000 times fainter than the faintest stars visible with
the naked eye) or brighter -- easily bright enough to
detect the small comets. The images were recorded on CD
ROM, analyzed at the UI, and remain available for
independent analysis on the web at
http://denali.physics.uiowa.edu/rlm
. Among several UI
undergraduates who assisted on the project were Christopher
Anson of Muscatine and William Peterson of Iowa City, both
seniors. Mutel and Fix said that the search, which was
conducted at Frank's suggestion, should have detected more
than 80 small comets if they are present in the predicted
numbers.
Frank, an experimenter, co-investigator or principal
investigator on some 40 spacecraft and an AGU Fellow, first
announced the small comet theory in 1986, after examining
images recorded in photographs taken by Dynamics Explorer
1. Frank and his colleagues had designed and built a
special camera to take pictures of the northern lights,
including the first images of the complete ring of the
northern lights from above the North Pole. Some of the
images contained unexplained dark spots, or atmospheric
holes. After eliminating the possibility of equipment
malfunction and numerous other explanations, Frank and
Sigwarth concluded that the atmospheric holes represented
clouds of water vapor being released high above Earth's
atmosphere by the disintegration of small comets composed
mostly of snow.
They calculated that more than 25,000 comets enter the
atmosphere each day. At that rate, the comets would have
added about one inch of water to the Earth's oceans every
20,000 years -- enough to fill the oceans over billions of
years. Frank said that not only their small size --
20-to-30-feet in diameter -- makes observation difficult,
but also that water striking the upper atmosphere glows
very faintly as compared to the bright glow of metal and
rock in solid meteors. The small comet theory was in the
news again after the 1996 launch of Polar, with its two
sensitive visible light cameras and one far-ultraviolet
light camera, offered sharper photographic images. At the
May 1997 AGU meeting Frank showed a series of Polar
satellite photographs that included a picture of a small
comet the size of a two-bedroom house disintegrating
thousands of miles above the Atlantic Ocean.
Mutel and Fix said that they were glad to be able to
contribute data to the discussion and added that the debate
over the small comet theory will likely continue for many
years to come.
==================
(3) POSSIBLE METEORITE FALL IN DUNBOGAN
From Gordon Garradd <loomberah@ozemail.com.au>
Dear Benny,
I have spoken by phone with Mr Paul Hancock, whose house
has the hole in the roof, he is becoming rather tired of
phone calls after being contacted by 17 media
organisations! He told me the sound was only heard by his
family inside the house, at 10:05 pm ( 11:05UT), and the
next door neighbour heard no sound at all. Mr Hancock heard
no other sounds and was unaware of any other reports of
sounds in the region, nor reports of fireballs. I put my
all-sky camera out at 10:20 UT, so may have recorded any
potential fireball, although my eastern view is obstructed
by trees in the direction of Dunbogan.
Mr Hancock described the dozen or so fragments he still has
as having a total volume of about half a golf ball. He gave
some of the material to the police for analysis, I
suggested he send some to the Australian Museum for a
proper analysis. He said the material seemed to have a
charcoal coloured lustrous surface "less than one sixteenth
of an inch thick" and inside a very even non -crystalline
"ghost grey" colour with no apparent variations.
The object smashed through glazed concrete tiles and the
ceiling and landed on the floor, where he found many pieces
of it mixed in with pieces of the tiles, he said he could
find no burn marks.
Regards, Gordon
===========
(4) ICE AGES, MILANKOVITCH & COSMIC DUST
From Doug Keenan <Doug.Keenan@virgin.net>
Benny,
The research described in the following suggests that ice
ages are caused, in part, by variations in Earth's orbit
that result in changes in the flow of cosmic dust into the
atmosphere. The variations are influenced by the
gravitation of other planets.
http://news.excite.com/news/uw/991208/tech-247
Cheers,
Doug Keenan
============
(5) CLIMATE CYCLES & ASTRONOMICAL CYCLES
From EXITE NEWS, 8 December 1999
http://news.excite.com/news/uw/991208/tech-247
UC-Berkeley research: Longterm climate change due to astronomical
cycles
By Westyn Branch-Elliman
Daily Californian U. California-Berkeley
(U-WIRE) BERKELEY, Calif. -- Climate cycles on Earth are directly
related to astronomical cycles in the solar system, UC Berkeley
researchers have found.
The team of scientists collected evidence of ice ages stored at
the
bottom of the oceans and found that there is a distinct pattern
of
cycles -- an ice age that lasts approximately 90,000 years is
followed by a warm period that lasts approximately 10,000 years.
"Astronomy is responsible for almost all climate
changes," said
project leader Richard Muller, a UC Berkeley professor of physics
and
a researcher at Lawrence Berkeley National Laboratories.
In addition, the researchers examined the astronomical cycles
caused
by variations in the tilt of Earth's orbit. They found that the
tilt
cycles match the cycles of the ice ages.
"When we look at ancient records of planets, these
astronomical
cycles appear in the climate record," Muller said.
Due to gravitational forces caused by other planets, the tilt of
Earth's orbit changes depending on the position of these other
objects.
"The orbit of the earth around the sun is constantly
changing due to
the gravitational effects of other planets," Muller said.
The law of gravitation is dependent on the distance between two
objects. When objects are closer together, they exert stronger
forces
on each other than when they are farther apart.
Other planets orbit the sun, so their proximity to Earth varies
over
time. Due to gravitational forces exerted by other planets, the
tilt
of Earth's orbit changes in a cyclic pattern.
"By using the laws of physics, we can figure out what kind
of cycles
(other planets) induce on the orbit of the earth," Muller
said.
The two planets that most strongly affect the tilt of Earth's
orbit
are Jupiter and Venus, Muller said. Jupiter is large an massive,
so
the planet exerts strong gravitational forces on Earth. Venus is
relatively close to Earth, so it also has a large effect on the
tilt
of the orbit.
"Jupiter, which is the biggest planet (in our solar system),
is the
most important," Muller said. "The other planet that is
very
important is Venus. Even though it is much smaller, it comes much
closer to the earth."
The team of scientists found that the tilt of the earth goes up
and
down every 100,000 years -- the same amount of time required for
one
ice age-warm age cycle to be completed, he said.
"The history of the ice ages for the last 1 million years
shows that
they also have 100,000-year cycles," Muller said. "The
pattern is an
excellent match."
The scientists found that ice ages occur when the earth's orbit
is
less tilted, although Muller said he did not know which tilt
would
result in a warm period and which one would result in an ice age
when
he began the project.
"We did not know which it would be when we started,"
Muller said.
"What we are actually looking at is the sea floor. Every
year, another
layer of sediment forms. These layers contain (a record of the
climate)."
The scientists determined the climate cycles on Earth by
collecting
sediments at the bottom of the ocean. Every year, a layer of dust
is
added to the ocean floor. This sediment holds the record of the
climate and the atmosphere, Muller said.
The researchers examined the sediments and found that certain
periods
were characterized by large amounts of oxygen isotopes, which are
oxygen atoms with extra neutrons. These isotopes indicate the
amount
of ice present in the earth's climate at the time the sediment
reached the ocean floor.
During ice ages, there are more oxygen isotopes present in the
sediment than there are during warm periods.
The scientists are now trying to figure out why the tilt of the
earth
has such a strong effect on its climate.
An old theory, later proven incorrect, theorized that the
climactic
cycles on Earth are caused by differential amounts of sunlight
hitting the earth's surface.
Although the sunlight theory was found to be wrong in the case of
long-term climactic cycles, many researchers continue to believe
that
climate change is directly related to astronomical cycles.
Muller said his group does not know exactly what causes the
cycles,
but thinks that changes in the amount of dust in the earth's
atmosphere is a likely cause of the cold periods.
"We have lots of guesses and we are trying to figure out
which one is
correct," Muller said. "The first guess is dust. Dust
hitting the
Earth has the same cycles as the ice ages."
Although the cycles match, scientists are not sure that dust
alone
could cause dramatic climate changes.
"The problem (is that) the amount of dust is so small, it
does not
seem there is enough to affect climate (this much)," Muller
said.
"Our best guess as of right now is that changes in the dust
affect
the formation of clouds. Remarkably, cloud formation is not well
understood."
Muller said that if the greenhouse effect is not considered in
climate analysis, the Earth's climate will soon cycle back to a
cold
period. "Ignoring global warming, then the ice age is due
back any
millennium now," Muller said. "The ice age is coming
back."
Muller said the current warm period has lasted approximately
10,000
years. Over the past million years, warm periods have lasted
between
5,000 and 20,000 years.
"Our warm period is 10,000 years long," Muller said.
"At the
beginning of that warm period, humans developed
agriculture."
Muller said the question of how the climate cycles is important
to
study because it directly affects the way human societies
function.
"All of civilization has taken place during this short and
relatively
unusual warm period, which won't last very long," Muller
said. "We
have been through 10,000 (years of this warm period), so some
time
in the next 10,000 years, another ice age will arrive."
Although some believe that the coming of an ice age could be
averted
because of the effects of global warming, Muller said that the
two
problems occur on very different time scales.
"Many people think that maybe we need global warming
(because) it
will keep another ice age from coming, but that argument is silly
and
wrong," Muller said. "These two effects are very
unlikely to cancel
each other. Global warming (is an effect) for the near future;
the
ice age relates to the distant future."
He added that the only way for human society to combat these
climate
problems is to study them.
"Both (global warming and the coming ice age) will likely be
disastrous," Muller said. "What we need is not to try
to get them to
cancel each other -- we need to understand them better."
It is important to study ancient climates, Muller said, because
the
past is often the key to the future.
"What we are really studying are ancient climates in order
to give us
insight into the future," Muller said. "I can't imagine
a more
important question."
Scientists must often be detectives to get their job done, Muller
said.
"There is a wonderful wealth of data (and) clues,"
Muller said. "Our
role as scientists is analogous to the role of Sherlock Holmes.
(We)
walk into a room and look at all these clues and then try to find
one
pattern -- the one explanation that answers the question."
(C) 1999 Daily Californian via U-WIRE
============
(6) SUNLIGHT KEEPS COSMIC DUST AT BAY
From ESA News Service, <sciweb@estec.esa.nl>
The force of sunlight is keeping part of our solar system dust
free -
at least free from a particular type of dust. Markus
Landgraf, now
working at ESA's operations centre ESOC in Germany and his
international team of colleagues, made this discovery after
poring over
data collected by the dust detector on board the Ulysses
spacecraft.
More at:
http://sci.esa.int/newsitem.cfm?TypeID=1&ContentID=8571&Storytype=13
==============
(7) EARTH REPORT 2000: MORE DOUBTS ABOUT GLOBAL WARMING
PROPHECIES
From Competitive Enterprise Institute
http://www.cei.org/books/earthreport2.html
Chapter Summary
Chapter 2
How do We Know the Temperature of The Earth?: Global
Warming and Global Temperatures
By Roy W. Spencer
Highlights
The popular perception of global warming as an
environmental catastrophe can not be supported with
measurements or current climate change theory. As
scientific understanding of the climate system improves,
estimates of future warming continue to fall. Even if
warming does prove to be substantial, the time required for
it to occur (many decades) will allow humanity considerable
time to better understand the problem, and formulate any
policy changes that might be deemed necessary.
Concerns about possible catastrophic global warming are
based largely upon computer model predictions that the
atmosphere will respond by amplifying the initial warming
tendency.
As computer models of the climate system have been improved
in recent years, their projections of the magnitude of
global warming by 2100 continue to be revised downward (3.3
deg. C in 1990, 2.6 deg. C in 1992, and 2.2 deg. C in
1995). The warming of 0.6 deg. C (1 deg F) in the last
century is only about one-half of what current global
warming theory predicts should have occurred.
Climatologists compute from measured greenhouse gas
increases that the atmosphere's ability to trap infrared
radiation has increased by about 1% compared to
pre-industrial times. This should have caused an imbalance
in the Earth's energy balance, resulting in a warming
tendency. What they don't know, however, is how the
atmosphere is responding to either limit or amplify
this small warming tendency.
All weather processes act, directly or indirectly, to cool
the surface of the Earth. While the Earth's natural
greenhouse effect would like to warm the average surface
temperature to near 130 deg. F, evaporation of water and
heat transport from the surface to the upper atmosphere
reduces this to a much more comfortable 55 deg. F. Computer
climate models do not simulate weather processes well.
Weather systems are the atmosphere's way of removing excess
heat. This is a consequence of the Second Law of
Thermodynamics: a fluid system like the atmosphere acts to
remove differences in temperature between different
locations. Water in the oceans and the atmosphere is an
extremely important part of the Earth’s heat removal
process, acting in many ways, like Freon does in an air
conditioner or heat pump, moving heat from one location to
another.
Detecting any global warming increase of 0.2 deg C, or 0.35
deg C per decade is difficult. The rate of temperature
change associated with daily weather is about 100,000 times
larger than the widely predicted 0.35 deg. F per decade
global warming signal.
It has been estimated that the Earth has warmed by about 1
deg. F in the last 100 years. However, studies have shown
that most of that warming has occurred at night and during
the coldest winter months.
The surface temperature data using land and ocean based
thermometers show a warming trend of 0.15 deg C per decade.
By contrast, weather balloon temperature data show a
cooling trend of -0.07, -0.04, or -0.02 deg. C/decade,
depending upon which research group is analyzing which
weather balloon data. And recently corrected satellite data
has produced a slight warming trend of +0.01 deg. C/decade
for the period of 1979-1997.
All measurement systems agree that 1998 was the warmest
year on record. The most recent satellite measurements,
through 1998, give an average warming trend of +0.06 deg.
C/decade for the twenty year period 1979-1998. Even though
this period ends with a very warm El Nino event, the
resulting trend is still only one-fourth of model predicted
average global warming for the next 100 years for the layer
measured by the satellite.
Global surface air temperatures were widely reported to
reach record warm levels in 1997 and 1998. What wasn't
mentioned was that most of this warmth occurred over the
tropical oceans, where a strong El Nino was occurring.
©1999 Competitive Enterprise Institute
===============
(8) VOLCANIC ERUPTIONS & OZONE DEPLETION LEAD TO COOLING
OF ATMOSPHERE
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Los Alamos National Laboratory
Los Alamos, New Mexico
CONTACT: James Rickman, 505-665-9203, elvis@lanl.gov
A COOLING TROPOSPHERE AND GLOBAL WARMING CAN CO-EXIST
SAN FRANCISCO, Dec. 16, 1999 -- Researchers at the U.S.
Department of Energy's Los Alamos National Laboratory say
they may have found a way to dispel a major objection to
global-warming theory.
"We want the global-warming community to know that we've
identified a possible explanation for why satellite
atmospheric temperature and surface temperature trends can
disagree," said Charles "Chick" Keller, director
of Los
Alamos' Institute for Geophysics and Planetary Physics.
"The truth is that the temperature trends probably do agree
when you consider the effect that massive ozone depletion
caused by large volcanic eruptions has on the stratosphere
and upper troposphere."
Keller and his colleagues -- Manvendra Dubey and Howard
Hanson of Los Alamos' Atmospheric and Climate Sciences
Group, and Tracy Light of Los Alamos' Space and Atmospheric
Sciences Group -- presented their findings today at the
American Geophysical Union's fall meeting in San Francisco.
The researchers set out to explain why scientists have seen
less warming in the troposphere, the lowest layer of the
atmosphere, than at the surface. If global warming were
actually occurring, some scientists have said, then
observers should be able to document warming trends in the
atmosphere as well as on the surface. This doesn't always
happen, however, and critics of global-warming theory use
the trend disparity to discount the idea that Earth is
slowly heating due to a buildup of greenhouse gases such as
carbon dioxide and other environmental factors.
Keller and his colleagues on the Los Alamos team looked at
existing temperature data gathered by high-altitude
balloons and satellites for clues about atmospheric warming
trends.
"When you look at the first 13 years of satellite
temperature records, you see pretty good agreement with the
surface records. But from 1992 to 1997 there is
disagreement. During that time the stratosphere -- the
atmospheric layer above the troposphere that contains the
ozone layer -- cooled dramatically," Keller said. "We
wondered if we could see some factor that would cause this,
and that's when we started looking at the June 15, 1991,
eruption of Mount Pinatubo in the Philippines."
The massive eruption spewed huge quantities of ash and
aerosols into the stratosphere. Through a complicated
mechanism, volcanic dust enhances destruction of ozone by
chlorofluorocarbons already present. Consequently, the
eruption led to a wholesale depletion of Earth's protective
ozone layer in the stratosphere, which has been observed.
Because ozone absorbs the sun's ultraviolet rays, the layer
normally heats the stratosphere; but with depletion of
ozone from the volcanic blast, the stratosphere cooled.
"We surmise that this very cold stratosphere might have had
a cooling effect on the troposphere, the lower atmospheric
layer where the weather is," Keller said.
Keller and his colleagues noticed that after the Pinatubo
eruption and subsequent stratospheric cooling, surface
temperatures and atmospheric temperatures first cooled,
then began to rise at comparable rates, but they maintained
a temperature differential greater than what had been seen
before the volcano.
The observation also led Keller and his colleagues to look
at how El Nino and La Nina phenomena affected the
atmosphere during the entire satellite record period from
1979 to present. As a general rule, during El Nino years,
the upper and lower troposphere see greater warming than
the surface, and tropospheric layers see greater cooling
than the surface during La Nina years. However, this was
not the case after Mount Pinatubo erupted. Keller and his
team looked at temperatures during the 1992 El Nino season.
The upper troposphere was cooler than expected during that
year, indicating that a cold stratosphere nestled directly
above may have affected the troposphere.
Moreover, Keller and colleagues noticed that researchers at
the Max Planck Institute for Meteorology had used a
computer simulation with a crude approximation of ozone
depletion to look at atmospheric temperatures and found
that the upper troposphere did cool during the aftermath of
Pinatubo. The Los Alamos researchers see this as another
indication that their tropospheric-cooling hypothesis has
merit.
Keller said he and his team next will use Los Alamos
computer models of oceans and sea ice coupled with computer
models of the atmosphere and land surface developed by the
National Center for Atmospheric Research to tackle the
problem. His research team will plug in 20 years of correct
ozone concentrations to see whether the models will arrive
at the level of atmospheric cooling measured during the
1992-1997 time frame.
"Critics of global warming hold the hypothesis that global
warming doesn't exist because it isn't seen in the
atmosphere by satellites," Keller said. "This
observation
by our team potentially eliminates one of the prime
objections to global-warming theory. I think further study
could show that ozone depletion keeps the whole system from
warming up, which is what you see in the satellite
temperature data."
Los Alamos National Laboratory is operated by the
University of California for the U.S. Department of Energy.
==============
(9) METEORS & INTERPLANETARY DUST
From Robert Hawkes < rhawkes@mta.ca
>
IAU Comm. 22 (Meteors and Interplanetary Dust) Electronic Notice
There are a limited number of extra copies of the
Proceedings of the Meteoroids 1998 International Conference
(held Aug 17-21 1998 in Tatranska Lomnica, Slovakia)
available for sale to libraries and those individuals who
wish to purchase a copy. The volume contains 80
papers
(invited reviews and contributed research papers), and is
405 pages in length. The main divisions of the volume are
Atmospheric Interaction, Meteor Observations, Meteor
Showers and Meteoroid Streams, Dynamics in Space, and
Physical Studies and Meteorites.. The volume is edited by
W.J. Baggaley and V. Porubcan, and is published by the
Astronomical Institute of the Slovak Academy of Sciences.
The program for the conference (which lists paper titles)
is still available on the www at:
http://www.ta3.sk/~ne/Meteoroids98/ann3.html
Copies of the Meteoroids 1998 Proceedings are available for 40
US$.
For further information and to place orders please contact:
Dr. Vladimir Porubcan
Astronomical Institute, SAV
Dubravska 9
842 28 Bratislava
Slovak Republic
astropor@savba.savba.sk
==============
(10) SNOWBALL EARTH
From Michael Paine < mpaine@tpgi.com.au
>
Dear Benny,
The January 2000 issue of Scientific American has a feature
article Snowball Earth. It is available online at
http://www.sciam.com/2000/0100issue/0100hoffman.html
"Ice entombed our planet hundreds of millions of years
ago,and complex animals evolved in the greenhouse heat wave
that followed"
regards
Michael Paine
==============
(11) AND FINALLY: CREATIONS, COLLISIONS & COMETS
From Stephen Ashworth < sa@astronist.demon.co.uk
>
Dear Benny Peiser,
Other CCNet subscribers may be interested to know about my
new dramatic millennial poem "Creation", which I have
just
published, price 4.00 Pounds sterling.
It tells the story of a lunar city, about 100 years in the
future, which is threatened by destruction through
collision with a cometary nucleus. My inspiration was
Pushkin's "The Bronze Horseman", which tells the story
of
how St Petersburg was devastated in the flood of 1824. But
the philosophy behind my poem is an optimistically
progressive one, although the progress is tempered by
tragedy, which must be faced with courage if it is to be
overcome.
I hope you will find this to be appropriate for a new
century in which stunning new insights into our place in
the universe continue to share the limelight with wars and
natural disasters.
The poem begins as follows:
Upon the living brink of crystal deeps
Stood the Designer with sky-challenging gaze.
A crumb of bread -- he mused -- a sip of wine
Vanish among ten billion trillion suns
That chime slow eons of galactic time.
What hope that ever mortal flesh and dreams
Could overcome these stark infinities?
More sample verses can be found at:
http://www.astronist.demon.co.uk/AstroPub01.html
With best wishes,
Stephen Ashworth (Mr)
Fellow of the British Interplanetary Society
Webmaster, Space Age Associates
15 December 1999
**********************************************
Stephen Ashworth, Oxford, UK sa@astronist.demon.co.uk
My dramatic millennial poem "Creation" is now
available,
price £4.00 (post free). It tells a story of love and
danger in the futuristic domed city of Tranquility on the
Moon. See http://www.astronist.demon.co.uk/AstroPub01.html
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