Estimating high-spatial resolution surface daily longwave radiation from the instantaneous Global LAnd Surface Satellite (GLASS) longwave radiation product

In this paper, time extension methods, originally designed for clear-sky land surface conditions, are used to estimate high-spatial resolution daily longwave (LW) radiation from the instantaneous Global LAnd Surface Satellite (GLASS) product. The performance of four methods were first tested by using ground based flux measurements that collected 141 global sites. Combined with accuracy LW estimated GLASS radiation, linear sine interpolation method performs better than other and was employed as follows: bias/Root Mean Square Error (RMSE) −6.30/15.10 W/m2 upward (LWUP), −1.65/27.63 downward (LWDN), 4.69/26.42 net (LWNR). We found lengths diurnal cycle longer durations between sunrise sunset we proposed increasing day length 1.5 h. accuracies improved after adjusting length. bias/RMSE −4.15/13.74 LWUP, −1.3/27.52 LWDN, 2.85/25.91 LWNR. producing long-term values