The distribution of wave-antiwind offsets for the different period ranges, each panel showing a different range of time and day of year. Summer is defined as day of year between 90 and 270 inclusive, whereas winter includes all days after day of year 270 and before day of year 90. Pre and post reversal refer to before and after 15:30 UT respectively. Winds are taken at an altitude of 220 km. The colours indicate the proportion of waves within the given period bin which fall into each 10° wide azimuth bin.