The Beautiful Roles of the Earth Rotation

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The Beautiful Roles of the Earth Rotation

• Climate presents abundant, beautiful, and
  colorful rhythms. Theoretically, its periods can
  be from zero to indefinitely long. Climate in a
  sense is so visible that every body can predict
  the coming mornings, months and seasons if one
  needs to know them for getting ready for them,
  which makes us feel safe. On the other hand, the
  weather and climate are such rhythm-abundant that
  no body can predict it exactly, and no body can
  go through the exactly same weather conditions in
  two days in ones life. This gives invisible charm
  to climate lest making us feel bored.
• The rotation of Earth plays basic roles in the
  climate rhythms by remembering forcing on
  multiple periods, maintaining orderly and stable
  motion of geophysical fluids, etc..
• ---- Capriccio from Physical Oceanography
• Zhiren (Joseph) Wang

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1. Sustaining Earth rotation

• 1-1.Rotation associated Coriolis force does not
  do the work on the objects (fluids) at any time
  therefore, the rotating Earth does not consume
  its energy and can keep its original angular
  momentum to
• rotate on and on.

Rotation-induced Coriolis force
Coriolis force is always perpendicular to
fluid motion at any moment, the work done to
fluids is
Where,
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• Similar force exists in magnetic field, but the
  bioelectricity inside our bodies should never be
  bothered by magnetic field.
• Force from a magnetic field ( ) exerted on a
  charged particle (q) with instantaneous velocity
  ( ) and forces work anytime are

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• 1-2.Rotation velocity does not change sensibly,
  and Earth does not shake terribly, even though
  bothered by abnormal mass
• distribution on the surface.

With the possible maximum unevenness of mass
distribution, e.g.,with 1 km of increased ice
sheet covering the whole hemisphere, I
established a simple model to compute obliquity
and rotation velocity
Schematic for basic parameters and relationships
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Obliquity changes no more than 3
Obliquity vs ice sheet thickness-extent.
Iso-lines indicate inertia momentum
Rotation velocity of Earth changes no more than
0.03
Rotation angular speed vs ice sheet thickness and
extent. Iso-lines indicate inertia momentum
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2. Rotation associated Coriolis force maintains a
relatively orderly and steady geophysical motion
and corresponding weather and climate.
This is done through geostrophic motion and Ekman
transport. Coriolis force balances most of
gradient force to produce geostrophic motion
moving along iso-bars, keeping most fluids from
moving from high to low pressure, only small
geostrophic departure moves from high to low
pressure through Coriolis force associated Ekman
transport to form weathers. If Earth did not
rotate, there would be no geostrophic motion,
fluids would move from high to low pressure
directly and quickly to erase the pressure
unevenness.
Schematic diagram for the jobs of Earth
rotation-induced geostrophic motion and departure
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3. The rotation of Earth plays the key role for
memory of forcings.
With the rotation of Earth, geophysical fluids
can memory forcings to have multi-period
oscillations. All the periods depend on the
Earth-rotation. Without the rotation, the memory
for both the basic and comprehensive periods
would totally lost Wang et al.,B. The basic
memorial periods for geophysical fluids to memory
forcings are
,
,
,
4. Rotation associated geostrophic motion
increases the predictability of geophysical
fluids as it causes geotrophic motion and waves
(Kelvin, Rossiby, etc.). Wang et al., A,C

The curvature force ( ,
) and friction are small ( is
other external forces). Coriolis force and
pressure gradient force are two major terms in
kinetic balance, which dwarf the nonlinear term
. Without Coriolis force, pressure
gradient force would be very small, nonlinear
term would stands up, making geophysical motions
much more unpredicable. Fortunately, the
equatorial region, where Coriolis force is zero
or very small, provides an open effective channel
to external forces from Sun and Moon and makes
climate from chaos, together with rotation.
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5. Earth rotation can muffle Sun-Moon
gravitation-induced flow and keep the geophysical
fluids from heaping onto a fixed direction.
For fluids of small viscidity the vertical speed
of which can increase by 29 (for Moon) to 365
(for Sun) times if without rotation Wang et al.,
B. This maybe is one of the reasons why there is
no fluids on Moons surface. For solids or fluids
of very big viscidity, rotation does not that
matter. Obviously, rotation avoids the solar
heating from being fixed at one Earth side for
too long and makes heating distribution even.
Schematic for cumulated motion induced by the
Sun-Moon attraction
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6. Further discussions
The sustaining Earth rotation together with
obliquity and revolution are maintained to
basically define the visible semi-diurnal,
diurnal, seasonal, and annual rhythm in weather,
climate, and the related astronomical phenomena.
Without consuming angular momentum of Earth,
Earth rotation maintains the geophysical fluids
with desirably stable and even high and low
systems, remembers the external drives with
multi-periods makes weather and climate charmy
and elegant of both linear and nonlinear,
quasi-geostrophic, quasi- and multi-periodical,
partially predictable, etc. produces
multi-waves and motions in abundant ways,
including Kelvin, Rossby, Ekman, initio,
inito-gravity, geostrophic, quasi-geostrophic,
cyclonic, anti-cyclonic, etc.. directly and
indirectly forms and changes various weather and
climate components ----in atmosphere, makes the
poleward motion turn to east and equator-ward
motion turn to west, forming multi-meridional and
zonal circulation cells (Hadley, Ferrel, polar,
Walker, ect.,), issuing various belts for wind,
rain, temperature, and pressure (trade winds,
midlatitue westerlies, polar systems,
inter-tropical convective zone, subtropical
highs, jets), guiding Monsoon, etc. ----in
ocean, even the wind-driven current and
thermohaline are very abundant Moonson-driven
Indian currents, equatorial currents systems,
intensified narrow western boundary currents,
broad weak eastern boundary currents, polar
currents, etc. avoids the solar heating from
being fixed at one Earth side for too long and
makes heating distribution even, keeps Earth
fluids from being attracted at a fixed direction
for too long and from escaping and son on. If
Earth did not rotate, or rotating rate were too
fast or too slow, or Earth rotated in the
opposite direction, the current beneficial
weather and climate would be changed, the fluids
would either exist on Earth in an odd (more
chaotic) way or escape from Earth. Both ways make
the non-rotational Moon have no fluids on its
surface, from the view of the intelligent design
or reality.
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• For instance, Earth rotated in the opposite
  direction with the same self-rotation angular
  speed and revolution period,
• then
• Solar day length would reduce from 24 hr to ,
  there would be 367.25 days within one year (2
  days more than current year). The periods for
  semidiurnal and diurnal signals and for the
  heating and tidal-forcing time on a fixed point
  would be shorter, caUse the changes in tidal,
  climate, biology,
• geology, and human activities.

Basic parameters Earth revolution period
T365.25days, number of sidereal days within 1
year Nstr366.25 days, length of 1 sidereal day
Tstr243600365.25/366.2586164 secs, Earth
rotation angular speed
.Earth rotation angular
speed relative to Sun
(1/s)
k-1 for current Earth rotation k1 for
opposite Earth rotation.
Length of 1 solar day
24hr for current Earth rotation, 23.87 hr
for opposite Earth rotation.
Number of solar days within 1 year
365.25 days for current Earth rotation,
367.25 days for opposite Earth rotation
Schematic diagram for solar and sidereal
day-lengths with Earth rotating (a) antilockwise
and (b) clockwise (with Earth-orbital velocity
unchanged,not plotted to scale).
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All the motions and waves that are controlled
under Earth rotation would change their
directions oppositely in both northern and
southern hemispheres, including geostrophic flow,
inertio-motion, gradient (cyclonic and
anti-cyclonic) flows, Ekman and other similar
transports, Kelvin wave, Rossby wave,
inertio-wave, inerto-gravity waves, tidal wave,
etc.. The concerned circulations would also
change their directions oppositely in both
northern and southern hemispheres, including
trade winds, Monsoon, jets (e.g., upper
troposphere jets, Somali jet stream), wind belts
(original westerlies/eastlies would be
easterlies/westerlies), Walker cells oceanic
current systems equatorial, polar,
west-boundary, east-boundary, Indian
etc.. Together with the given topography,
land-sea distribution, and astronomical
conditions (e.g., Moons motion), further weather
and climate changes would occur with the changes
in periods and directions listed above. The
inter-tropical convective zone (ITCZ), Monsoon,
and Walker cells would change. The original warm
pool would change into cold pool and the warmer
sea surface would shift to the east tropical
Pacific and west tropical Indian due to the
change of trade winds. Compared with the original
warm pool located in joint Indian-Pacific, the
two new warm pools would get weaker, Walker cells
would get weaker. Thermocline would weaken as it
would reverse its direction. The original strong,
warm, and narrow western-boundary poleward
currents (e.g., Kuroshio and Gulf stream) would
change into weak, cold, and broad currents toward
equator the weak, cold, and broad east boundary
equatorward current would be strong, warm, narrow
poleward current. Indian-Himalaya Monsoon driving
mechanism would change and even shift to the east
Pacific region with weakened intensity due to the
new atmospheric and oceanic circulation patterns.
The temperature and precipitation patterns
would correspondingly change. E.g., east coasts
would get drier and colder west coasts would get
warmer and moist. And the global climate
variations tend to be smaller with the weakened
ENSO and Monsoon. Ect..
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7. References
Wang, Zhiren, et al., A The basic wave
characteristics and climatological meanings of
Suns-Moons gravitation and solar radiation (to
be contributed). Wang, Zhiren, et al., B The
nonlinear response and multi-temporal scales of
cumulative momentum memory for geophysical fluids
to Sun-Moon gravitation (to be contributed). Wang
Zhiren,D.X. Wu , D. Chen, H.D.Wu, X.J.Song and
Z.H.Zhang, C Critical Time Span and Nonlinear
Action Structure Of Climatic Atmosphere and
Ocean. ADVANCES IN ATMOSPHERIC SCIENCES,
Vol.19,pp741-756,2002.