An extract of such file is given hereunder (note that the lines are not complete):

The files are column-oriented. The meaning of each column is.

1. decimal day (convention 1:0 = January 1st, current year, 00 UTC)
2. year
3. month
4. day of month
5. hour (UT)
6. minute
7. second
8. longitude (decimal degree, positive east of the Greenwich meridian)
9. latitude (decimal degree, positive in the Northern Hemisphere)
10. altitude (m)
11. pressure (Pa)
12. air temperature (K)
13. zonal velocity (m/s)
14. meridional velocity (m/s)