In February 1968, when the incident flow was 60 cm/sec toward the northwest, a wake resembling a von Kármán vortex street was present in the ocean downstream of Johnston Atoll (16°45'N, 169°31'W). In October 1968, when the incident flow was 15 to 20 cm/sec, no wake was detected....
Barkley, Richard A.. 1972. "Johnston Atoll's wake." Journal of Marine Research 30, (2). https://elischolar.library.yale.edu/journal_of_marine_research/1239