Project

General

Profile

Extrapolate into NaN areas when doing a remap

Added by Christian Stepanek almost 13 years ago

Hi,

I have a reconstruction of sea surface temperature that I would like to use to force ECHAM with. Due to a small mismatch in the land sea mask of the reconstruction and the model setup, there are some comparably small regions in coastal areas, where I need a temperature forcing, but have no information on the paleo sea surface temperature available.

It would be very convenient if there was an automatic way of increasing the area of the reconstruction during interpolation to the t31grid, by extrapolating into the NaN area. In the documentation of the most recent version of CDO I found that there is a switch called REMAP_EXTRAPOLATE. I would like to know how exactly one could do a remapcon or remapbil with extrapolating into NaN areas by using this switch. According to the documentation, for remapcon and remapbil REMAP_EXTRAPOLATE in general is switched off, therefore as a general rule no extrapolation into NaN areas is made - how do I switch it on to change this behaviour? Do I need to execute a command like 'export REMAP_EXTRAPOLATE=TRUE' in the shell at some point before invoking the cdo remap-procedure? I played around a little, but so far I did not find the "magic trick". Unfortunately I did not find an explanation in the online documentation of cdo.

Thanks a lot for any hint.
Christian


Replies (2)

RE: Extrapolate into NaN areas when doing a remap - Added by Ralf Quast almost 13 years ago

Hi,

I have looked into the source code because I am interested in solving the 'Missing Value interpolation problem' too. The correct option for activating the extrapolation switch is 'export REMAP_EXTRAPOLATE=on' but I do not know what the option actually implies.

RE: Extrapolate into NaN areas when doing a remap - Added by Ralf Mueller almost 13 years ago

I created an issue on this: #1105.

    (1-2/2)