Skip to Main Content
The mean depth–time curves and the mean density–time curves are given in Figure 5 (below 1,400 m a.s.l.) and Figure 6 (1,400–2,000 m a.s.l.). Mean and σ of ρ are calculated using the moving window averaging technique (±16 days) including all data from the respective elevation zone. When the number of records drops below 50 in May (see Figures 5(b) and 6(b)) no mean HS and ρ values are given after 7 May (below 1,400 m a.s.l.) and after 25 May (1,400–2,000 m a.s.l.). In the lower elevation zone, mean HS starts with 0.23 m and the peak of the mean HS curve (0.5 m) is reached at the end of February. Mean ρ starts with 160 kg m−3 and rises up to 350 kg m−3 in mid-April. After that, mean ρ decreases due to late season records with ephemeral snow covers (Figure 5). In contrast, data from above 1,400 m a.s.l. result in a rising ρ until mid-May. While ρ below 1,400 m a.s.l. rises in an almost linear manner throughout the season, densification shifts to a higher rate in the upper elevation zone in March. The shift of the densification rate goes hand in hand with a flattening of the mean HS curve at approximately 0.9 m (Figure 6). Simultaneously, the range of mean HS ±1σ becomes largest. Daily densification rates show a large noise and, therefore, monthly mean values are calculated (Table 2). Below 1,400 m a.s.l., densification rates have a low variability, with monthly values ranging from 0.9 kg m−3 d−1 in January to 1.35 kg m−3 d−1 in March. Above 1,400 m a.s.l., densification rates are around 0.6 kg m−3 d−1 from November to January. After a transition phase in February, densification reaches its maximum rates in March and April (1.8–1.89 kg m−3 d−1).
Table 2

Monthly mean values of daily densification rates of the Tyrolean station data

 Densification kg m−3 d−1
< 1,400 m a.s.l.> 1,400 m a.s.l.
Nov 0.96 0.61 
Dec 1.06 0.59 
Jan 0.93 0.62 
Feb 1.12 1.20 
Mar 1.35 1.89 
Apr 0.84* 1.80 
May – 1.34 
 Densification kg m−3 d−1
< 1,400 m a.s.l.> 1,400 m a.s.l.
Nov 0.96 0.61 
Dec 1.06 0.59 
Jan 0.93 0.62 
Feb 1.12 1.20 
Mar 1.35 1.89 
Apr 0.84* 1.80 
May – 1.34 

*Mean value for daily densification rates between 1 April and 20 April as density decreases afterwards.

Figure 5

Long-term mean (1952–2010) of (a) snow depth–time curves and (c) density–time curves of Tyrolean station data of the elevation zone below 1,400 m a.s.l. The number of records available for calculating the mean values is given in (b).

Figure 5

Long-term mean (1952–2010) of (a) snow depth–time curves and (c) density–time curves of Tyrolean station data of the elevation zone below 1,400 m a.s.l. The number of records available for calculating the mean values is given in (b).

Close modal
Figure 6

Long-term mean (1952–2010) of (a) snow depth–time curves and (c) density–time curves of Tyrolean station data of the elevation zone 1,400 m a.s.l. to 2,000 m a.s.l. The number of records available for calculating the mean values is given in (b).

Figure 6

Long-term mean (1952–2010) of (a) snow depth–time curves and (c) density–time curves of Tyrolean station data of the elevation zone 1,400 m a.s.l. to 2,000 m a.s.l. The number of records available for calculating the mean values is given in (b).

Close modal
Close Modal

or Create an Account

Close Modal
Close Modal