Sea-level pressure observations from Dutch ships 1854–1938 incorporated in COADS Release 1c climatology



The quality of the 5.7 million punched sea-level pressure observations from Dutch ships for 1854–1938 has been under debate due to ambiguities in the gravity correction. The observations were omitted from the 1985 COADS (Comprehensive Ocean–Atmosphere Data Set) Release 1 monthly summaries. We re-examined the Dutch data with the help of original meteorological ship logs. It is concluded that the Dutch procedure for pressure reduction was consistent throughout time. The Dutch data are incorporated in the recent (2001) COADS Release 1c. This increases the number of COADS pressure observations for 1854–1938 by about 28%. For the 1854–80 subperiod the increase is more than a factor two. Copyright © 2003 Royal Meteorological Society