Jökull - 01.01.2009, Blaðsíða 7

Langjökull, energy balance and degree-day models
Figure 3. Energy budget at G500 dur-
ing the summer 2001 (a), in com-
parison with weather parameters (b-c)
and albedo (d), displayed as three-day
moving averages. The error is esti-
mated as ±20 W m"2 for Mc, ±7
W m"2 for R and ±19 W m"2 for
Hd + Hl. – Veður- og orkuþættir í 500
m y. s.
Table 3: Degree-day factors of the models DDM1 and DDM2 (locations of stakes are in Figure 1). After melt-
ing through the winter snow layer, the surface at 1100 m (around the ELA) consists of firn, and ice at 500–1000
m. The errors are given as one standard deviation of estimated annual variance of the ddf -parameters. – Stuðlar
í reynslubundnum líkönum.
AWS/stake Elevation ddf1 ddf2
(m a. s. l.) mm !C"1 mm !C"1
snow firn/ice snow firn/ice
G1100: Stake & AWS 1100 10.8± 0.9 11.5± 0.4 5.2 ± 0.5 6.3± 0.4
Stake 1000 10.9 13.5 5.5 6.7
Stake 900 11.1 12.3 5.6 6.7
Stake 700 10.0 11.3 5.9 6.7
G500: Stake & AWS 500 8.0 ± 1.6 11.1± 1.2 6.1 ± 0.3 7.5± 0.2
JÖKULL No. 59 7