The net radiation (Rn) is the difference between the incoming net shortwave radiation (Rns) and the outgoing net longwave radiation (Rnl).
cal_netRadiation(Rns, Rnl)
A vector for net radiation
incoming net shortwave radiation. From cal_netSolarRadiation().
outgoing net longwave radiation. From cal_netLongwaveRadiation().
Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. FAO Irrigation and drainage paper No. 56. Rome: Food and Agriculture Organization of the United Nations, 1998.