Documentation 
The specifications of the globally gridded meteorological data are:
Time resolution: 6 hours, 00/06/12/18 UTC Horizontal resolution: 1 deg spacing in latitude and longitude Vertical disretization: 19800101  20011231: 23 pressure levels from ERA40reanalysis 20020101  20071105 (06 UTC): 21 pressure levels from operational data 20071105 (12 UTC)  now: 25 pressure levels from operational data, in [hPa]: 1/2/3/5/7/10/20/30/50/70/100/150/200/250/300/400/ 500/700/800/850/900/925/950/1000
Preprocessing the ECMWF data for the calculation of AAM involves the following models:
Digital elevation model: ETOPO5 (http://www.ngdc.noaa.gov/mgg/global/etopo5.html) Geopotential model: EGM96 (Lemoine et. al, 1998). Geoid undulations are determined up to degree and order 360, for gravity values the expansion is truncated at degree 2.
Consistently, WGS84 is employed as horizontal datum and the height system is orthometric. The node data of each meteorological parameter are averaged to a mean value for every 1 deg cell.
The three components of AAM are split up into matter (components c12, c23, c33 of the inertia tensor, units [kg m2]) and motion terms (relative angular momentum, units [kg m2 / sec]). Depending on the calculation scheme applied for numerical integration, two files are available for each day: yyyymmdd_ps_vxxx.aam and yyyymmdd_dp_vxxx.aam, where vxxx refers to the version number of the produced files.
Columns 16 have the same content in both files: 14: Year, month, day, hour of the initialization epoch 5: Forecast step in hours 6: mjd of the forecasted epoch Remaining columns in yyyymmdd_ps_vxxx.aam: 79: nonIB mass terms, determined as double integral over surface pressure 1012: IB mass terms, //
Remaining columns in yyyymmdd_dp_vxxx.aam: 79: nonIB mass terms, determined as volume integral over pressure increments 1012: motion terms, //
http://ggosatm.hg.tuwien.ac.at/ROTATION/AAM/VERSION1/readme_aamv1.txt

Data 
YYYY MM DD HH, forecast hours, MJD, nonIB mass terms (x,y,z), IB mass terms (x,y,z)
