by Bernie McCune
This whole discussion began with a posting on Watts Up With That by Hartmut Hoecht posted on July 11, 2018.
It is worth reading the whole thing but I will summarize it here. Various ways of measuring ocean temperatures from long ago until present times are discussed and questions of uncertainty and errors are raised. Recent and even very old reports on sea surface temperature (SST) values are often given in fractions of a degree. In reality, until very recently, the collection process had obvious errors that were greater than one degree.
Cooling periods in the SST records seen in the 1940s and 1970s of 0.3º C were noted in the data with some concern about collection methods but this period is known to be a AMO[efn_note]Atlantic Multi-Decadal Oscillation (AMO) is a climate cycle index that has a roughly 60 year period. The natural variation of the average sea surface temperature of the North Atlantic Ocean basin from the equator to 80o N is used to produce this index.[/efn_note] (and with less influence PDO[efn_note]Pacific Decadal Oscillation (PDO) is another climate cycle index that also has about a 60 year period. It is related to the El Nino Southern Oscillation (ENSO) and is a robust, recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20°N. It was named by biologist Steven R. Hare in 1997 when he noticed it while studying salmon production pattern results in the North Pacific Ocean. This climate pattern also affects coastal sea and continental surface air temperatures from Alaska to California.[/efn_note]) 30 year cooling period. In order to discern these 0.3º C changes in the data, instruments with an accuracy of 0.1º C must be used. The rule of thumb noted that the instrument must have better than three times the accuracy of the targeted Continue reading “Systematic Temperature Error in the Climate Change Discussion”