how can I modify the date in a dump file

[jcrook]

I want to take start dumps from HadGEM2 10 days apart and make them look like they all have the same date in them so I can then start an ensemble of simulations. Is there a utility to change the date in dump files? I can use xconv to convert the dump to netcdf then modify the date but how can I turn the netcdf back to a dump file?

[grenville]

Please see the last line of the web page:

http://cms.ncas.ac.uk/wiki/ToolsAndUtilities/UmFileTools

where it refers to the change_dump_date utility.

To run it (courtsety of Jeff Cole),

change_dump_date dumpfile year month day hour minute second

all the date/time arguments are optional

For example

jasmin1:jeff$ change_dump_date dumpfile 1999 12 1
file dumpfile is a byte swapped 64 bit ieee um file
Changing dump file date to 1999/12/01:00.00.00

jasmin1:jeff$ change_dump_date dumpfile 1999 12 1 12
file dumpfile is a byte swapped 64 bit ieee um file
Changing dump file date to 1999/12/01:12.00.00

jasmin1:jeff$ change_dump_date dumpfile
file dumpfile is a byte swapped 64 bit ieee um file
Changing dump file date to 0000/01/01:00.00.00

It actually changes the fixed length header values 28-33 but not the pp header values. This means the file will still have the old date if you look at it with xconv but when run in the UM it will use the new date value.

Grenville