II
RELATIONSHIP BETWEEN OCEAN AND ATMOSPHERE
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4st
PART
Weekly height ocean surface
Around
our blue planet have been putting satellites into orbit satellites
(Jason, Topex-Poseidon...) orbit to measure the height of
the oceans with their altimeter at few centimeters near. It
is from this information it is possible to know what is going
on in depth : the density of water, salinity, temperature,
and therefore the currents.
So
from these data are provided and monitored the movement and
extent of El Nino or
La Nina.....
TOPEX-POSEIDON
and JASON I and II of the NASA / CNES are satellites that
measure the weekly height of the sea surface (SSH) with high
accuracy and oceanic currents. The instantaneous accuracy
average of the local estimate of the ocean level is better
than 5 cm, and the average precision on a month better than
2 cm.
Here are the main satellites
measuring or measured the level... of the oceans :

THE TOPEX-POSEIDON SATELLITE
FROM 10/08/1992 TO 12/07/2001

THE JASON SATELLITE I
FROM 15/09/2001 TO 2008

THE JASON II SATELLITE
FROM 20/06/2008 A 2013

These satellites measure the height
of the water. The radar signal transmitted by the satellite
is reflected by the surface. From round trip time the distance
is calculated from the satellite
relative to the ocean. Then a station sends a laser for the
satellite to determine its distance from
the station. It also receives signals from Doris marks. From
these satellite calculates its distance
in relation to the center of the Earth. After making the difference
between its distance in relation to
the center of the earth and the distance of the satellite
in relation to the ocean we get the ocean height.
Click
here to see an animation that explains how these satellites
measure the sea level
During El Niño and La Niña
(ENSO) in the Pacific
and the North Atlantic Oscillation (NAO)
weekly sea surface height anomalies were found from measurements
of the satellite Topex-Poseidon.

Calculation of the shift in sea level
in the North Atlantic (except seasonal
variations and turbulence) from the satellite Topex-Poseidon.
The variation
of the NAO index (in red) during
the same period is also shown. (Credits
Cnes)

It is thus that from Topex-Poseidon
data from 1993 to 2000, it has been possible
to notice that the sea level dropped and flowed in different
regions and not in the same way.

Click
here to see a video (9.30 MB) of the variation of the SSH
(height of the sea surface) over 5 years from September 1992
to September 1997 from the Topex-Poseidon measurements
.gif)
WARNING
Patricia
Régnier helped me correct mistakes, please you to visit
her
blog
Im not english speaker, some improprieties can appear
to english masters.
Could you help me reporting by mail any fault you read. Thank
you for all.
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