Answer 1:
Not all scientists agree if weather like hurricane
Mitch was caused by pollution. No one is sure.
Those that do say that pollution does affect the
weather say that pollution causes the air to warm
which causes changes in the weather. Scientists
do generally agree that on local scales, say
around a city, pollution does affect when it rains
and makes it more likely to rain on the
weekends.
One of the scientists involved is
Randall Cerveny at Arizona State University who
did the study. Just in case your internet
connection is down, here's the text:
"Study
suggests weekly hurricane and rainfall patterns
are linked to East Coast pollution
Who
hasn't felt like going back to work on Monday has
affected the weather? It turns out the weather
itself may indeed be controlled by the weekly
calendar, and that even mighty Atlantic hurricanes
may feel the punch of the workweek, according to a
study by two Arizona State University researchers
appearing in the journal Nature.
Examining
some basic data sets in a way that has never been
tried before, ASU climatologists Randall Cerveny
and Robert Balling, Jr. have found proof for what
many a weekend boater has secretly suspected: rain
is most likely to occur along the Atlantic coast
on the weekend and the weather is most likely to
be better on a Monday, Tuesday or Wednesday. The
most obvious culprit is the "natural"
cloud-seeding effect created by the massive drift
of East Coast pollution, which also follows a well
defined weekly cycle.
The gray, smelly
cloud of pollution has a strange silver lining,
however. While pollution makes for more rainy
weekends, it also apparently reduces the intensity
of hurricanes that hit over the weekend, such that
weekend hurricanes tend to be much weaker than,
say, Tuesday storms.
"Hurricanes are the
biggest storms that we have on this planet, in
terms of energy and precipitation," noted Cerveny.
"And what we've found is that we're having an
impact on them. It's a little daunting, when you
start to think about it."
Cerveny and
Balling examined and compared three different data
sets daily carbon monoxide and ozone measurements
from a Canadian monitoring station on Sable Island
off the coast of Nova Scotia, daily
satellite-derived rainfall data for the Atlantic
Ocean, and databases of coastal Atlantic hurricane
measurements. In each case, when the two ASU
scientists examined the data by day of the week,
they found significant differences between days,
and similar patterns of variation, with pronounced
differences between beginnings and the ends of
weeks. All three sets of climate data revealed a
seven-day cycle.
"The human week is not a
natural time period," said Balling. "Human effect
on weather is the only explanation."
"If
you're going to go out boating in the Atlantic,
you're going to get wet if it's a weekend,"
Cerveny said. "And what we suggest is that this is
probably linked to the pollution cycle."
In
examining precipitation in the Atlantic, they
found no daily variation when looking at the ocean
as a whole, but a pronounced sine-wave pattern of
variation for just the coastal areas, with average
daily precipitation rising on Thursday and into
the weekend and then dipping from Sunday through
the middle of the week. Balling notes that when
the team analyzed satellite data grid cells for an
area a little further away from the coast, they
found the same pattern, time-shifted in accordance
with the rate of pollution drift.
Though
the study does not directly address causation, a
comparable fluctuation in the levels of East Coast
air pollution points to an obvious connection. The
fact that coastal hurricane intensity data taken
from 1945 to 1996 follow a similar pattern (rather
than being statistically uniform for each day of
the week, as one would expect), supports this
hypothesis.
"The fact that pollution can
affect rainfall is actually well understood," said
Balling. "We just had to look for the evidence in
the right place. The hurricane data, though,
surprised the heck out of me." "We knew
that cities have an effect on local weather with
urban heat islands and so forth, and people are
pretty sure that we're having a general global
effect with carbon dioxide," said Cerveny. "But
nobody had ever looked at the in-between area of
large-scale regional weather. We appear to be
affecting global weather on a scale that is
comparable to El Nino."
The hypothesis is
particularly important when applied to hurricanes,
because of the destructive potential of the
storms. Cerveny and Balling looked at 50 years
worth of hurricane records, which include
observations taken every 6 hours and found
surprising statistical differences with important
implications. "Storms are substantially
weaker during the first part of the week and
stronger in the last part of the week," said
Cerveny. "Pollution's thermal changes on the storm
are apparently helping hu |
Answer 2:
The effect on the weather may not be direct. It
could be a result of increased warming,
though.What happens when you close all your car
windows on a summer day? It gets really hot in
there, right? If you leave the windows open,
it's a lot cooler. Pollution can form a layer in
the atmosphere that doesn't allow heat to escape,
just like the windows trap heat in your car. This
is called the "greenhouse effect". Many
scientists think this will lead to global warming.
Others aren't sure. Hurricanes (and all winds)
are caused by a mass of warm or hot air meeting a
mass of cold air. So with more hot air, can we
expect more or worse hurricanes? How could we
test that hypothesis?
Here is a site about
hurricanes:Envirolink
This
site has more information on the greenhouse
effect:Greenhouse |
Answer 3:
Certain types of pollution can affect weather in
the long term. For example, green house gases
(some indirectly caused by pollution and others
are a direct result of pollution) work by trapping
more of the sun's heat energy than normal in our
atmosphere, thus warming the planet (global
warming). This causes global weather changes.
For example, scientists believe that El Nino might
be caused by pollution in an indirect way via
global warming. Also, the severity and frequency
of hurricanes has been steadily increasing in the
last several years and scientists believe that
also might be due to global warming. However, I am
not aware of how pollution can cause immediate
effects on weather or very specific effects, such
as the generation of a specific hurricane. The
greenhouse gases that have been found to be in
increased concentrations include carbon dioxide,
methane, and even water. Why do you think carbon
dioxide levels might be increasing in the past
~100 years?
|
Answer 4:
I don't know anything about air pollution causing
hurricane Mitch, but if is true that pollution can
affect weather. The best example of this is that
carbon dioxide from power plants and cars has
caused Earth's surface temperature to warm about 1
degree Fahrenheit. We know for sure that the
earth's surface is getting warmer, and we know for
sure that we have polluted the atmosphere with
extra amounts of carbon dioxide, but we don't
know for sure that the higher carbon dioxide is
what is causing the global warming. Computer
models, however, make a very good argument for
carbon dioxide being the cause. Air pollution
in the form of dust and smoke particles can help
clouds to form, and that, too, can have an effect
on weather. I hope this helps.
Click Here to return to the search form.
|