##############################DESCRIPTION OF THE MDT_CNES-CLS09_v1.1.ascii file ############################################
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The MDT_CNES-CLS09_v1.1.ascii file contains the values of the CNES-CLS09 Mean Dynamic Topography (v1.1 release) computed in the framework of 
the SLOOP project from the French Space Agency CNES. 
It was computed using a similar method than for the RIO05 MDT solution (Rio and Hernandez, 2003; Rio et al, 2005): 
First, a large scale Mean Dynamic Topography is obtained from the CLS01 altimetric Mean Sea Surface and a geoid model.  
Then, altimetric sea level anomalies are subtracted from in-situ measurements of the ocean state (dynamic heights and 
geostrophic surface velocities) to compute synthetic estimates of the MDT and the corresponding geostrophic mean currents. 
Finally, the synthetic estimates, and associated errors, are inversed through a multivariate objective analysis method to 
map the Mean Dynamic Topography on a ¼° resolution grid.

Compared to the previous RIO05 MDT, the main improvements are:
-	The use of the recent EIGEN-GRGS.RL02.MEAN-FIELD based on 41/2 years of GRACE data
-	The use of an updated dataset of drifting buoy velocities (1993-2008) and dynamic heights (1993-2007), including 
	the ARGO data.
-	The use of an improved Ekman model to extract the geostrophic component of the buoy velocities 
-	The use of an improved processing method of the dynamic heights allowing to make use of T/S profiles to different 
	reference depths.
-	Estimation was done on a ¼° resolution grid (instead of ½° for RIO05).

Warning : The CNES-CLS09 MDT is an estimate of the ocean MDT for the 1993-1999 period. 
The ocean MDT for a different time period P can be easily deduced using altimetric Sea Level Anomalies referenced to the 
1993-1999 period :

MDTP=MDT93-99+<SLA93-99>P

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Contact : Marie-Hélène Rio 	email=mrio@cls.fr
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Reference : Rio, M-H, P. Schaeffer, G. Moreaux, J-M Lemoine, E. Bronner (2009) : A new Mean Dynamic Topography computed 
over the global ocean from GRACE data, altimetry and in-situ measurements . Poster communication at OceanObs09 symposium, 
21-25 September 2009, Venice.  
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The MDT_CNES-CLS09.fic  ASCII file contains the values of the mean heights and corresponding geostrophic velocities on a 
regular ¼° global grid.

The format of the file is the following  (9 columns) :

LON	LAT	H	U	V	ErrH	ErrU	ErrV	Flag

Where :

LON	=	Longitude of the grid point, ranging between 0.125°E and 359.875°E
LAT	=	Latitude of the grid point, ranging between 79.125°S and 80.625°N
H	=	Mean Dynamic Topography (unit=meter) ranging between -1.695m and 1.807m
U	=	Zonal component of the mean geostrophic velocity (unit= m/s) , ranging between -1.32 m/s and 1.23 m/s
V	=	Meridian component of the mean geostrophic velocity (unit= m/s) , ranging between -1.11 m/s and 1.40 m/s
ErrH	=	Error on the Mean Dynamic Topography (unit=meter), ranging between 0.0 and 0.14 m
ErrU	=	Error on the mean zonal velocity component (unit=m/s) , ranging between 0.0 and 0.97 m /s
ErrV	=	Error on the mean meridian velocity component (unit=m/s) , ranging between 0.0 and 0.66 m/s
FLAG	=	Flag indicating the availability (flag=0) or not (flag=1) of synthetic observations for 
		the MDT inversion. If Flag=1, values are from the MDT first guess computed from the CLS01 MSS and 
		GRACE geoid.

Default value is 9999.0000

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