About a year ago the Sea Weather: Office issued a small publication on wave statistics as the first result of wave observations by weather ships in the North Atlantic. This was done to overcome the existing need for information on the frequency of the various sea states in the North Atlantic.
The present publication is to be considered as complementary to the above-mentioned research. The basic period of the observations has been increased from one to two years; to wit from 1 November 1950 to 31 October 1952. In addition to giving the frequency distributions of wave heights and wave periods (viz. lengths) subdivided as in the previous publication, we have tried to derive the frequency distribution for specific combinations of both variables. On the basis of this representation, it is possible to make certain statements as to the wave steepness.
The observed data have been taken from the weather radio messages of the North Atlantic weather ships. Because the original logbook observations have not been published as yet, it has been necessary to take into account the reduction inaccuracy of the data due to the coding as well as the possibility of errors in transmission which always exist with the radio messages. However, spot checking of the original data against the radio messages have a good agreement, and the confidence in the weather news service has so increased that the possibility of transmitting errors can be considered as negligible.