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\f0\fs26 \cf0 Note date 2013-03-18\
\
1) Monthly GRACE gravity fields are available for the January 2013 \
   and February 2013 in the following files:\
\
   GSM-2_2013001-2013031_0030_JPLEM_0000_0005   2013   JAN (see 1.b)\
   GSM-2_2013032-2013057_0026_JPLEM_0000_0005   2013   FEB (see 1.b)\
\
     REMARKS:\
     1.a - For each of those months, an unconstrained 90x90 field is provided.\
     1.b - For each of those month, an unconstrained 60x60 field is provided.\
     1.c - The standard deviations of the harmonics included in the GSM-2*\
           products represent ONLY formal (NOT calibrated) errors of the\
           estimate.\
     1.d - These filenames end with the string "_0000_0005", denoting \
           the Release 5 Level-2 products.\
     1.e - Due to the increasing errors in the monthly fields at higher\
           degrees, users are cautioned against using spherical harmonic\
           coefficients past approximately degree 70 in the monthly fields.\
     1.f - The principal difference of these products relative to the \
           Release-04 are significant upgrades to the background gravity\
           Model (now GIF48), updated ocean tides, RL05 atmosphere and ocean\
           de-aliasing product, the use of version 2 L-1 data,\'caand a change\
           to the processing strategy which\'caeliminates some of the regional\
           biases (primarily Greenland and the North Atlantic) present in \
           RL04.1, although with a small increase in solution "stripiness".\
           These model upgrades are described in the JPL Level-2 Processing \
           Standards Document - version 5.0. Changes to the parameterization \
           are also described in that document.\
     1.g - The rate of low degree and order gravity harmonics coefficients\
           were removed from the processing of the GRACE data. The details \
           of background models for GRACE data processing can be found in \
           the "JPL L2 Processing Standards Document for Level-2 Product \
           Release 05".\
     1.h - The value of C20 derived from GRACE in RL05 (as with many of the \
           Analysis centers) is less well observed. Users should substitute the \
           SLR values for best results.\
\
2) For each month six product files are available. For example, the available\
   products for January 2008 are:\
\
     GSM-2_2008001-2008031_0031_JPLEM_0000_0005\
     GSM-2_2008001-2008031_0031_JPLEM_0000_0005.README\
     GAA-2_2008001-2008031_0031_JPLEM_0000_0005\
     GAB-2_2008001-2008031_0031_JPLEM_0000_0005\
     GAC-2_2008001-2008031_0031_JPLEM_0000_0005\
     GAD-2_2008001-2008031_0031_JPLEM_0000_0005\
\
     REMARKS:\
     2.a - The monthly GAA, GAB, GAC, and GAD files are the monthly averaged\
           harmonics from AOD (RL05).\
     2.b - The zero-th and first degree terms in GAA, GAB, GAC, and GAD \
           products have not been applied in the level-2 gravity recovery \
           process.\
     2.c - The averaging of GAA, GAB, GAC, and GAD are carried out over a \
           whole number of days, regardless of whether full or partial day's \
           data were used in creating the GRACE monthly solution.\
     2.d - The header information in these files contain slightly different \
           values of GM (Earth gravitational parameter) and Ae (Earth \
           equatorial radius) - when compared to the values in the headers of \
           the geopotential product files GSM*. All analysis has been done with \
           the values using the GM and AE values in the headers of the GSM* \
           files.}