A 
T. Spangehl et al.: Intercomparing the quality of recent reanalyses for offshore wind farm planning 
REA6 @FINO1, 100 m, 2004-2009 
(a) 
50 
A} 
251050 
151025 
01015 
31010 
5108 
4106 
0la4 
Imys) 
a 
ERAS @FINO1, 100 m, 2004-2009 
{c) 
15% 
‘251050 
151025 
191015 
31010 
5108 
1106 
004 
Im) 
f 
X 
Fa 
25 10 50 
151025 
101015 
31010 
ib8 
106 
do4 
'nvs) 
HoKlISim-De @FINO1, 100 m, 2004-2009 
(d) 
P 
25 to 50 
151025 
101015 
31010 
108 
106 
üt04 
mnvs) 
FINO1, 102 m, 2004-2009 
{e) 
15%. 
25 1a 50 
'51025 
‘01015 
31010 
5108 
4106 
0104 
Im) 
Figure 3. Wind rose of hourly wind speed and direction at 100m for model based products at FINO1 grid points. Results are shown 
for (a) COSMO-REAG, (b) CERRA-fc, (c) ERA5 and (d) HoKliSim-De. Results obtained from (e) hourly FINO1 measurements (10 min 
averages) of wind speed at 102 m and wind direction at 91 m are additionally shown. The time period is 2004-2009. 
quencies are apparent decreasing from 6 % at W to about 5 % 
at NNW. Most of the sectors from N over E to S show relative 
frequencies of less than 5%. Here only the S sector and the 
E sector show values slightly above the 5% level. Sector E 
depicts a secondary maximum of about 6 %. 
The wind rose of COSMO-REAG6 (Fig. 3a) is in line with 
observations (Fig. 3e). Differences of less than 1 percent 
are seen for most sectors. COSMO-REAG6 slightly underesti- 
Adv. Sci. Res., 20. 109-128, 202, 
mates the frequent occurrence of the south-westerly wind di- 
rections seen in observations, especially for sector SSW. By 
contrast, the occurrence of wind directions at sectors W to 
NNW is somewhat more frequent in COSMO-REA6. In ad- 
dition, the relative maximum at sector E is less pronounced 
in COSMO-REAG6 and shifted to sector ESE. Wind speeds 
above 15m s”7! are predominately found for south-westerly 
https://doi.org/10.5194/asr-20-109-2023