AR ▁Re analysis ▁main ▁data ▁page . ▁ ▁Us es ▁▁ ▁Initial izing ▁a ▁smaller ▁scale ▁atmos pher ic ▁model ▁ ▁Cl imate ▁assess ment ▁ ▁Sub sequ ent ▁updates ▁ ▁Since ▁then ▁N CE P - DO E ▁Re analysis ▁ 2 ▁and ▁the ▁N CE P ▁C FS ▁Re analysis ▁are ▁released . ▁The ▁former ▁focus es ▁in ▁fixing ▁existing ▁bugs ▁with ▁the ▁N CE P / NC AR ▁Re analysis ▁system ▁– ▁most ▁not ably ▁surface ▁energy ▁and ▁usage ▁of ▁observed ▁precip itation ▁forcing ▁to ▁the ▁land ▁surface , ▁but ▁otherwise ▁uses ▁a ▁similar ▁numerical ▁model ▁and ▁data ▁assim ilation ▁system . ▁The ▁latter ▁is ▁based ▁on ▁the ▁N CE P ▁Cl imate ▁Fore cast ▁System . ▁ ▁See ▁also ▁ ▁EC MW F ▁re - analysis ▁Re anal ys es . org ▁website ▁Cl imate ▁Data ▁Guide ▁ ▁References ▁▁▁ ▁K ist ler , ▁R ., ▁E . ▁Kal n ay , ▁W . ▁Collins , ▁S . ▁Sah a , ▁G . ▁White , ▁J . ▁W ool len , ▁M . ▁Ch ell iah , ▁W . ▁E bis uz aki , ▁M . ▁Kan am its u , ▁V . ▁K ous ky , ▁H . ▁van ▁den ▁D ool , ▁R . ▁J enne , ▁and ▁M . ▁F ior ino , ▁ 2 0 0 1 : ▁The ▁N CE P - NC AR ▁ 5 0 - Year ▁Re analysis : ▁Month ly ▁Me ans ▁CD - ROM ▁and ▁Document ation . ▁Bull