Description
The authors analyzed diatom data they obtained from core MD992271 (66°30'05"N, 19°30'20"W) on the North Icelandic shelf to derive summer sea surface temperatures (SSTs) for that location based on relative abundances of warm and cold water species, after which they compared the results they obtained with results of similar analyses of nearby cores HM107-03 (66°30'N, 19°04'W) and MD992275 (66°33"N, 17°42'W). In the words of Jiang et al., "the Medieval Warm Period and the Little Ice Age are identified in the record," which from our visual assessment of their SST history appears to have prevailed between approximately AD 950 and 1250. Unfortunately, the MD992271 record ends in the midst of the Little Ice Age and therefore does not reveal any 19th- or 20th-century warming. The HM107-03 record, on the other hand, extends to within about 50 years of the present; but it too shows no evidence of warming at its end. However, core MD992275 does extend to the present; and it suggests that the temperature at the end of the 20th century was at least three-quarters of a degree Centigrade cooler than the peak temperature of the Medieval Warm Period.