[RADS] New models: which old ones can go?

Remko Scharroo remko at altimetrics.com
Wed May 21 03:00:39 CEST 2008

Dear RADS users,

Since you have come to expect a little bit more user-consultation from  
RADS than from the space agencies, I cannot but include you in the  
quandary of which models to drop after introducing new ones.

What follows here is a list of models that are due to appear in RADS  
in the following weeks and which ones may therefore become obsolete.  
Please make your voice heard if you do not like models to disappear  
that are on the "outgoing" list. Also, let me know if you want more  
models added now that I'm on the verge of making big data updates.

The EGM2008 gravity model is out in the form of spherical harmonics.  
While waiting for the "official" geoid grid, I've studied and tested  
the code that is delivered with it so that I can make that grid  
myself. I'll likely do that if it takes too long for the grid to appear.
EGM95 is the only geoid currently on the records. Does it harm anybody  
if I remove that one when EGM2008 comes in, or is there a strong  
desire to keep EGM95 (for a while)?

Our colleagues and RADS users at the Danish National Space Center have  
created as new set of surface models DNSC08. The DNSC08 MSS has a  
1'x1' resolution and could replace GSFC00.1, while I keep the more  
widely used MSS CLS01.

DNSC08 also includes a bathymetry grid made with the help of  
altimetry. This model surely is a major improvement over ETOPO2, and  
can thus replace it immediately.

Richard Ray developed a while ago the model GOT4.7, which reportedly  
is without competition in shallow water areas, surpassing both FES2004  
and GOT00.2. I suggest we pick up GOT4.7 (in anticipation of GOT4.8  
coming out later in the summer) and drop GOT00.2.

Eric Leuliette suggested to provide two separate fields with the long- 
period equilibrium tides and long-period non-equilibrium tides. I'm  
not going to take those two components out of the ocean tides, but  
rather provide them as separate fields for anybody to use separately.  
Those will probably be numbered 3901 and 3902.
The two components will come from the Cartwright-Tailor-Edden series  
and FES2004. FES2004 contains the equilibrium and non-equilibrium  
components of the weekly, fortnightly, semi-annual and annual tides.  
CTE contains the equilibrium tides of those waves and many others. So  
it will be a bit of work to split the two properly.

Eric also suggested to add the local mean of the MOG2D correction as  
an extra field in order to provide better comparison with tide gauges.

Just as on the Jason-1 data so far, I'll add the WW3 model output on  
all data from 2000 to 2005 (inclusive).

In short, NO reply is your CONSENT to:
REPLACE: EGM95 by EGM2008 geoid
REPLACE: GSFC00.1 by DNSC08 mean sea surface
REPLACE: ETOPO2 by DNSC08 bathymetry
REPLACE: GOT00.2 by GOT4.7 ocean and load tide
ADD: (non-)equilibrium long-period tides
ADD: mean MOD2D field
ADD: WW3 wind and wave model data to all data of 2000-2005.

Of course, I'll make sure to add ALIAS cards so that the removed  
fields will default to the new fields.


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