Regarding the precipitation forcing in ROMS

[yadusharma]

Hi All,
I have a question regarding the precipitation forcing.
While preparing the Precipitation forcing file for my ROMS model, I am confused with the range of rainfall values between the TRMM and GPCP daily data. Both data files say that both are in units of mm/day.

Here I am attaching the comparison of daily rainfall for Jan 01 2013. I would be grateful if anybody can point out the possible reasons for this difference and so which data I should use for forcing.