Instituto Tecnológico y de Estudios Superiores de Monterrey
Campus Guadalajara
Noctilucent Clouds
Roberto Javier Velázquez Valdéz 1083794
Aketzalli Valdivia Torres 1084534
Francisco Javier Delgadillo Casas 1084370
Integral Calculus
Group: AP
Gloria Faus Landeros
March 29th 2007
 What are Noctilucent Clouds?
Noctilucent clouds are a phenomena that have been seen since the 1800’s,
especially during the summer in Alaska and in the northern areas of the world,
like France. They appear in the mesosphere zone from 50 to 85 km; however,
these fantastic clouds stay at an altitude of 80 to 85 km. The temperature of this
layer of the earth can range from –125ºC to –163ºC, and furthermore, it is a
very dry zone.
There are many theories about these phenomena and one of the first ones
was that they were the result of a big eruption caused by the Krakatoa volcano
since these ashes reached a very high altitude. This theory was rejected
because the clouds started to appear in other different places around the world.
Nowadays, there are more Noctilucent Clouds in the world, but the main
problem is that there is no specific cause and consequence of these, so they
are still unknown for us.
 Problem Statement
Our main objectives are the following:
 To analyze the different theories related to the causes of Noctilucent
Clouds.
 To understand why they are seen more during the summer and in northern
locations.
 To know how the solar rays enter the Earth; what their incident angle is, and
how they are reflected during the summer in Alaska.
 To analyze how they contribute to the greenhouse effect.
 To think about the possible consequences of the Noctilucent Clouds.
** We are going to use Trigonometry, Calculus, Chemistry, Physics, Astronomy,
Geometry, and other sciences in order to make a math model that represents
this phenomenon that we can use to study and solve this enigma.
 Hypothesis
The Noctilucent Clouds are harming the atmosphere because they contribute to
the greenhouse effect. They provoke more damage during the summer because
the sun’s rays are stronger during this season, specially in the northern
industrialized countries of the world. For this reason, global warming is
increasing, which contributes to the melting of the polar glaciers.
 Comparison between the possible components of
Noctilucent Clouds and polluted clouds.
Polluted Clouds
 H2O

CO2 (Carbon
Dioxide)

Methane gas

Nitrogen Oxide

Ozone

Clour flour
Carbures

NLC
Methane gas=Ice
Crystals
 Why do the sunrays heat stronger during the
summer in Northern places?

The inclination of the Earth is 23.5º.

During summer the incident angle of the solar rays in the North Pole
are bigger than in other seasons.

When it is summer in the North Pole, it is winter in the South Pole,
because of the incident angles of the sun’s rays.

During this season in the North Pole, the days are longer.
Summer.
Because of the angle inclination of the Herat (23.5 º), during Summer the
north places of the world are being heat more than the south places; for this
reason, when is Summer in the North Pole, in the South Pole is Winter. Another
important thing is that the incident angle of the solar rays is 30 º so that the rays
hit more directed during this season.
Incident Angle of the solar rays during summer.
 Some Important Theories
 Methane gas

Production source:
o Human activities
o Germ from the rice crops.
o Biomass
o Digestion and defecation of the animals (cattle)
o Residual water.
o Anaerobic putrefaction.
o Decomposition of organic matter.
o Natural sources like marsh.
o Extraction of fossil combustibles.
Properties of Methane gas.
Boiling point: -161.6ºC
Melting point:: -182.5ºC
Temperature of the mesosphere: –125º to –163º
Given the high temperature of this zone of the Earth, the methane gas
changes its internal composition for its physical properties. Furthermore, the
density of the Methane gas is lower than the density of the air, so the methane
gas can range very high altitudes. As a result, small crystal particles are formed.
For this reason, the Noctilucent clouds shine very much.
According to Vladimir Shaidurov of the Russian Academy of Sciences
explained how changes in the amount of ice crystals at high altitude could
damage the layer of thin, high altitude clouds found in the mesosphere that
reduce the amount of warming solar radiation reaching the earth's surface.
 Meteorite’s theory
It is thought that when a meteorite is falling down to the Earth, the cosmic
dust stays in the mesosphere because it breaks apart and it forms small
particles that form the Noctilucent Clouds; It is supposed that they are made
of oxides of heavy metals.
 Water’s Theory
This theory is focused that the water evaporates, and it stays in the
mesosphere forming crystals of ice that later get together to form the
Noctilucent Clouds. We reject this theory because the mesosphere is a dry
zone, so it would be difficult that the evaporated water could reach up to this
zone, and it is a place with low atmospheric pressure. For this reason, we reject
this theory.
 Why do the solar rays contribute to the Greenhouse
Effect?
The solar rays are luminous energy.
“The first law of the conservation for energy states that the energy can not be created,
or destroyed, and that energy can be changed from one form to another”.
Solar rays
Luminous Energy
Thermal Energy
More
Heat
Greenhouse
Effect
Global
Warming
It is the same in a light bulb, since the luminous energy becomes in heat
which is thermal energy. For this reason, when the thermal energy stays a lot of
time in a place, it can cause a lot of problems since there could be an overheat,
and this thermal energy can be expanded for other places.
 Possible Consequences

Polar glaciers would melt.

Ocean levels would increase, and as a result, many small islands would
disappear.

Many animal and vegetable species would disappear.

Humans would have many problems, especially due to the variation of
the weather.

Other possible natural disasters could occur because of change in the
weather.


The amount of salt water in the oceans would increase.
Conclusion
Although the Noctilucent Clouds are attractive for human observation, they
are a consequence of contaminants, which causes their influence on the
greenhouse effect. Since the sun’s rays stay in specific points of the Earth
holding heat and causing damages to human lives, we need to solve this
important global problem.
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