1998] and RCM output such
as incoming and outgoing, short- and long-wave radiation,
temperature, water vapor pressure, and wind speed:
ETref ¼
0:408D Rn Gð Þ þ g 900T þ 273 u2 es eað Þ
Dþ g 1þ 0:34u2ð Þ ð3Þ
where ETref is reference evapotranspiration (mm d1), Rn is
net radiation at the crop surface (MJ m2 d1), G is soil heat
flux density (MJ m2 d1), T is mean daily air temperature
at 2 m
/media/loftslag/vanRoosmalen_etal-2009-WRR_2007WR006760.pdf