Saturday, October 27, 2012

Tropical Cyclones

Hurricane Isabel (2003)
A tropical cyclone is a storm system centered about an area of low atmospheric pressure.

Low pressure sets an air mass into motion. This motion would be experience by as wind - wind with measurable intensity and direction.
The term cyclone refers to cyclical wind flow. The direction of wind flow in cyclonic systems is:
  • Counter-clockwise in the Northern Hemisphere, and
  • Clockwise in the Southern Hemisphere,
due to a rotational deflection known as the Coriolis force.

The Coriolis force deflects moving objects when they are viewed in a rotating reference frame such as the earth's rotation. Wind undergoes an apparent deflection from its path because of the rotation of the earth.
Hurricane Sandy 10/26/2012
“There is no way that we can predict the weather six months ahead beyond giving the seasonal average”
Stephen Hawking, from Black Holes and Baby Universes
Tropical cyclones originate over tropical oceans in the equatorial regions of the earth. A cyclone derives its energy from condensed water vapor. Condensation occurs as warm, saturated air rises from the ocean surface (evaporation) and cools.
“One of the fellows called me 'Cyclone' but finally shortened it to 'Cy' and its been that ever since.”
"Cy" Young, Major League Baseball pitcher (1867 – 1955).
A tropical cyclone is also referred to as a hurricane, a typhoon, a tropical storm, a cyclonic storm, a tropical depression, or simply a cyclone, depending on the global region and wind-speed intensity.

Name Wind Speed Global Region
Tropical Depression 38 mph or less
Tropical Storm 40 to 72 mph
Hurricane 74 mph or greater Western North Atlantic and Eastern North Pacific
Typhoon 74 mph or greater Western North Pacific


REFERENCES


Saturday, October 20, 2012

Golden Ratio in Nature

In words, the golden ratio is:
The ratio of the sum of two quantities over the larger quantity is equal to the ratio of the larger quantity over the smaller one.
The golden ratio expressed as an equation is:

(a + b) / a = 1.618 = a / b

From the golden ratio, we get a mathematical constant - a number. It is the number 1.6 which, by convention, is represented by the Greek letter φ (pronounced "fee").

The number φ is a mathematical curiosity. Like the mathematical constant π, φ appears everywhere.
Ginkgo Leaf
The good, of course, is always beautiful, and the beautiful never lacks proportion.
Plato
The golden ratio is found in the proportions of leaves. I measured the golden ratio in the leaf of a ginkgo tree.

Using the typographical units of pica, I measured 28 pica from the notch to the base of the stem of a ginkgo leaf. I then measured 17 pica from the top of the stem to the base of the stem (length a).

The quotient of 28 pica over 17 pica yields the golden ratio 1.6.

Scientists have recently observed nanoscopic symmetry. The symmetry they observed had the attributes of the golden ratio, demonstrating this curious proportion at the quantum level.
The universe cannot be read until we have learnt the language and become familiar with the characters in which it is written. It is written in mathematical language, and the letters are triangles, circles and other geometrical figures, without which means it is humanly impossible to comprehend a single word.
Galileo Galilei
References

Saturday, October 13, 2012

Earth Rhythms

Autumn is a time for noticing changes and for witnessing life-cycles. It is also a time that lends itself to introspection. For many, Fall is the season when:
we look, rather than overlook.
Horse Chestnut leaves on
the banks of the River Wye.
We are melancholic, but pleasantly befuddled by the essence of our mortality.

Autumn Leaves is a wistful tune sung by Nat King Cole and many talented singers.
Autumn Leaves
Johnny Mercer

The falling leaves drift by the window
The autumn leaves of red and gold
I see your lips, the summer kisses
The sun-burned hands I used to hold

Since you went away the days grow long
And soon I'll hear old winter's song
But I miss you most of all my darling
When autumn leaves start to fall

Translated to English from the 1945 French song Les Feuilles Mortes, i.e., "The Dead Leaves", the lyrics of Autumn Leaves expresses the longing we have for what we might have lost and for what we are about to lose.

Autumn is a rhythm of life. The earth's rhythms are plentiful and rewarding to those who observe them.

Earth's Rhythms

The word rhythm derives from the Greek ῥυθμός—rhythmos, meaning "any regular recurring motion, symmetry".

Rhythm describes a regular recurrence or pattern in time. Earth's rhythms appear in cyclical phenomena from microseconds to millions of years.

Time Scales

The rhythm of night and day is a Circadian Rhythm. The word circadian was coined by scientist Franz Halberg in 1959. It comes from the Latin words circa (i.e., around) and diem (singular of dies).

Halberg was a pioneer in Chronobiology (the study of biological rhythms, such as daily, tidal, weekly, seasonal, and annual rhythms). In the context of living organisms, circadian rhythms are both built-in and adjusted to environmental cues. Environment cues are called zeitgebers (i.e., a German word meaning synchronizers). One zeitgeber is daylight.

Relationship between ethological terms and parts of the day.
Circadian rhythms for living organisms are further described by the period within the cycle where they are most active, that is:
  • Diurnal (daytime);
  • Nocturnal (night time); and
  • Crepuscular (dawn and dusk hours).
The term Matutinal describes the pre-dawn or early morning hours. The morning glory is a matutinal flower that unravels into full bloom in the early morning. The flowers begin to fade a few hours before it closes its blooms later in the day. Vespertine describes dusk and evening hours where animals like deer are most active.

Other Rhythms

Echelon flock formation
of migratory birds
There are many temporal patterns other than circadian rhythm including the non-24-hour Infradian and Ultradian rhythms:

Infradian rhythms are cycles longer than a 24-hour day. For example,
  • the annual migration of birds;
  • the varied reproductive cycles of animals; and
  • the human menstrual cycle.
Ultradian rhythms are shorter than 24 hours. For example,
  • the 90-minute REM cycle;
  • the 4-hour nasal cycle of congestion/decongestion, and
  • the 3-hour cycle of growth hormone production.
Other notable rhythms include the cycle of ocean tides and gene oscillations in living organisms.
Tide pool in Portugal

Tidal rhythms are cycles that emerge from the roughly 12-hour transition from high to low tide and back.

Gene oscillations describe a phenomena where genes are more active during certain hours of the day (acrophase) and less active in the time (bathyphase).
I'm so glad I live in a world where there are Octobers.
L.M. Montgomery, from Anne of Green Gables
Meditation

There is a measure of serenity in earth rhythms, the seemingly friction-less spin of the earth, and the earth's reliable orbit around the sun.
Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you, and the storms their energy, while cares will drop away from you like the leaves of Autumn.
John Muir
All existence seems a pulsating rhythm. I wonder if my heart pulsates in harmony the changing color of leaves. At some level, I think it does.
...if you become aware of the fact that you are all of your own body, and that the beating of your heart is not just something that happens to you, but something you're doing, then you become aware also in the same moment and at the same time that you're not only beating your heart, but that you are shining the sun. Why? Because the process of your bodily existence and its rhythms is a process, an energy system which is continuous with the shining of the sun, just like the East River, here, is a continuous energy system, and all the waves in it are activities of the whole East River, and that's continuous with the Atlantic Ocean, and that's all one energy system and finally the Atlantic ocean gets around to being the Pacific Ocean and the Indian Ocean, etc., and so all the waters of the Earth are a continuous energy system. It isn't just that the East River is part of it. You can't draw any line and say 'Look, this is where the East River ends and the rest of it begins.'
Alan Watts
References

Saturday, October 6, 2012

Polar Ice

Polar ice forms because as high latitude regions the poles receive less solar radiation than equatorial regions, resulting in lower temperatures.

Sea ice is frozen ocean water. Icebergs, glaciers, and ice shelves float in the ocean but originate on land. Sea ice cools the poles, but also moderates global climate.

Polar bears 280 miles from the North Pole
Polar bears 280 miles from the North Pole.
I seemed to vow to myself that some day I would go to the region of ice and snow and go on and on till I came to one of the poles of the earth, the end of the axis upon which this great round ball turns.
Ernest Shackleton (1874 – 1922), Polar Explorer

Self-Perpetuating


Recently the Arctic has warmed twice as quickly as the rest of the northern hemisphere. Some aspects of changing climate is self-perpetuating.

Reflection / Absorption of Sea Ice
Sea Ice Reflection/Absorption in
Admiralty Bay, King George Island
Most sea ice is blanketed by reflective snow cover. About 80% of the sunlight striking snow-covered ice is reflected back into space.

Further, when soot from smokestacks in Europe and Asia migrate to the Arctic then settle onto the snow and ice, the darker particles absorb rather than reflect solar energy.

When sea ice melts, it exposes the darker, non-reflective ocean surface. Instead of reflecting solar energy, ocean water absorbs 90% of the incident solar radiation.

As ocean water warms, arctic temperatures rise.

Data

Sea ice data from the National Snow and Ice Data Center in Figure 1, indicate the mean monthly sea ice coverage has decreased between the years 1979 and 2012.

Figure 1.
A plan view representation of sea ice extent is shown in Figure 2. The white region, representing the footprint of sea ice on October 2, 2012, is shown in comparison to the median footprint of sea ice during the period of 1979-2000 (orange outline).

Figure 2.
Science

Earth Scientists know from the geologic record that polar ice has changed over the last 12,000 years. Changes have occurred because of varied solar radiation and absorption. Further, on a geologic time scale, ice cover has grown or shrunk because of climate variation.

Sea ice is melting more dramatically each year. Scientists concur the melt is driven by climate change correlating to pollutants humans release into the atmosphere. A 2012 study of multi-decade sea ice variability concludes that 70 - 95% of the disappearance of Arctic ice since 1979 is due to human activity.

Within 10 years it will be impossible to travel to the North Pole by dog team. There will be too much open water.
Will Steger

References

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