60

KLIWA$ 60

ICTP  REGCM3  KNMI  RACM02  METNO  HIRHAM  HC  HodRM3Q0
HC  HadRM3Q16  HC  HodRM3Q3  MPI  REMO  SMHI  RCA
Relative  frequency  of  wind  speed  classes
(=  length  of  spoke)
0  5  .0 t  '

Fig.  3.4.2.:  Wind  roses  from  ERA-40  data  (orange)  compared  to  RCM-data  (blue)  in  the  northwestern  area  of  the  North  Sea  area  for  the  period  1971-2000.
Length  of  each  branch  is  related  to  the  frequency  of  occurrence  of  the  respective  wind  direction,  see  legend  for  relation  between  frequencies  and  lengths.
Width  of  each  branch  broadens  with  increasing  speed  range.  Numbers  in  circles  denote  frequencies  of  calm  winds.