Inconsistent precision in MSIS_coeff.nc file

[Ian Culverwell]

Kjartan Kinch (DMI) discovered that these coefficients are being held at different precision in OCC (8 decimal places, from ascii file) and ROPP (read in from ascii file as single precision, then promoted to double precision before being written out as DP vars to netCDF file).

By reading them in as DP variables in ropp_pp/msis_bangle/MSIS_ascii2netcdf.pro we obtain a netcdf file at equivalent precision. For example:

ba_Ac0(1, 1, 1) from ascii ropp_pp/data/dabcs01.asc =

0.32796969E+02

ba_Ac0(1, 1, 1) from original ropp_pp/data/MSIS_coeff.nc =

3.27969703674316406250e+01

ba_Ac0(1, 1, 1) from revised ropp_pp/data/MSIS_coeff.nc =

3.27969689999999971519e+01

Unfortunately, it doesn't fix the original problem, but at least it's one less known difference between OCC and ROPP.

This change will be introduced at ROPP5.0.