Since version 3.6, REGRID can process fractional seaice data as well.
Fractional seaice data is used in MM5 if the polar physics option is
activated with IPOLAR = 1 in configure.user.

The source used for the fractional seaice data is:
National Snow and Ice Data Center, Boulder, CO, USA

This data can be obtained by anyone from the National Snow and Ice
Data Center at no charge (They only require users to register
with them before downloading data).

To download data, first register at:
http://nsidc.org/data/nise1.html (Near the top it says "Register for Data")
Once you are a registered user, you will be supplied with a user name
and password to download data.

If you use the data, there is a citation at the bottom of the 
same web page that you should stick in your references:
Nolin, A., R.L. Armstrong, and J. Maslanik. 1998 - [insert date of data acquisition]. 
Near Real-Time SSM/I EASE-Grid Daily Global Ice Concentration and Snow Extent. 
Boulder, CO, USA: National Snow and Ice Data Center. Digital media.

Questions about the original data?
nsidc@nsidc.org
(303) 492-6199

Where do you get the HDFEOS fractional seaice data?

Once you have registered, use the user name and password provided to go
to their ftp site:

ftp sidads.colorado.edu
user: provided-user-name
passwd: provided-pass-word

get the NISE_SSMIF13*.HDFEOS file for that date (name as of Nov 2002)

How to run?
1) Fill in the date in the namelist.input file.
2) Put the NISE*HDFEOS file in the current working directory.
3) Run the sea ice fraction executable:
	# seaicefr
4) Move the generated file (SEAICEFR_FILE:YYYY-MM-DD_HH) up a 
directory
	# mv SEAICEFR_FILE:* ..
5) This file is to be used as one of the "CONSTANTS_FULL_NAME"
files in the regridder namelist.input file.  

Only when the MM5 polar mods are used is fractional seaice required. 

Note that this conversion program only converts one date at
a time. This is normally enough, since regridder only needs
one time period of SEAICEFR data. (This data is ingested by
regridder via the "constants_full_name" variable in
regridder/namelist.input.)

If desired a user may use more than one time for SEAICEFR as input.
In this case, the pregrid/nise converter needs to be run separately for
each time period, and the data must be supplied to regridder via the
"root" variable in regridder/namelist.input.


Questions about use of the data in the MM5 system?
mesouser@ucar.edu
