Arctic lake sediment series have been an important component of recent multiproxy studies. These series have been discussed on many occasions at Climate Audit (tag), mostly very critical. PAGES 2017 (and related Werner et al 2017) made some interesting changes to the Arctic lake sediment inventory of PAGES 2013, which I’ll discuss today.
Some prior Climate Audit criticisms have resulted in withdrawal or major changes or lingering controversy, including:
There was some publicity this week on a paper by Young et al (Science Advances, 2015), which, according to Gifford Miller , whose work has been frequently discussed at CA (see tag), had supposedly put the “coup de grace on the Medieval Warm Period”, that had been so long wished for by the Team.
Since AR4, there have been a series of new multiproxy studies, several of which were cited in AR5 (Mann et al 2008; Ljungqvist et al 2010; Christiansen and Ljungqvist 2012; Shi et al 2013). A distinctive feature of these and other recent multiproxy studies is the incorporation of varve thickness and near-equivalent mass accumulation rate (MAR) series, in which varve thickness (positively oriented) is interpreted as a direct proxy for temperature.
In a previous post on PAGES2K Arctic, I pointed out that they had used the Hvitarvatn, Iceland series (PAGES2K version shown below), upside-down to the interpretation of the original authors (Miller et al), who had interpreted thick varves as evidence of the Little Ice Age. A few days ago, Miller and coauthors archived a variety of series from Hvitarvatn, prompting me to review this data.
