[CF-metadata] Standard name(s) needed for satellite-based ice drift products

From: Thomas Lavergne <thomasl>
Date: Fri, 24 Oct 2008 15:08:03 +0000

Dear all,

I am lacking standard name(s) for the satellite-based ice drift product I am producing.
Basically, "satellite-based ice drift products are not velocities", and, specifically, they do
not scale as m/s but as m (distances). I thus cannot use standard names like:

direction_of_sea_ice_velocity
eastward_sea_ice_velocity
northward_sea_ice_velocity
sea_ice_x_velocity
sea_ice_y_velocity

I am not sure the "community" ever agreed on a correct wording. I have the feeling we only are at a
point where we start being conscious of that aspect. Anyway, the last time I discussed about it with
my "satellite ice drift" colleagues (2 weeks ago), the consensus was on "displacement".
"Satellite-based ice drift products are not velocities but displacement". The difference being that
an ice drift product based on the analysis of pairs of satellite images is, primarily, an indication
that a given point on the ice P0=(lat0,lon0) moved between two times (t0 and t1) to an other
location P1=(lat1,lon1). But such a product cannot say anything on the trajectory (from t0 and t1)
which advected P0 to P1. Not having the trajectory, we do not have access to velocities
(instantaneous m/s) but only to displacements from t0 and t1.

So, it would be:

eastward_sea_ice_displacement [m] (length of [lon0,lon1] on Earth surface)
northward_sea_ice_displacement [m] (length of [lat0,lat1] on Earth surface)
sea_ice_x_displacement [m] (length from P0 to P1, taken along the grid's X axis)
sea_ice_y_displacement [m] (length from P0 to P1, taken along the grid's Y axis)
sea_ice_displacement [m] (the length [P0,P1] on Earth surface)
direction_of_sea_ice_displacement [degrees] (the direction to North of the [P0,P1] vector)


I can clarify my point further when the discussion starts, if needed.

Have a nice week-end,

Thomas Lavergne
met.no - Oslo - Norway
Received on Fri Oct 24 2008 - 09:08:03 BST