RichardT, thanks, I can now understand your point. The abstract points to the modern marine environment starting about 5.1 kyears BP in this ocean area, which I would assume would make intra comparisons during this time period more legitimate. I know that Steve M has commented about the upwelling regions of some of these core areas as being problematic. Do you have other references giving details of the oceanic history of other individual core areas used in the Kim and Lorenz papers?

Before I become too apologetic, I must submit what I found on further investigation of the core samples (alkenones) used in the Lorenz et al. (2006) and the Kim et al. (2004) papers. Looking at the cores identified specifically in the Lorenz paper and comparing them with those in the Kim paper I found 15 of 20 identified in the Lorenz were also indentified in the Kim paper. When I finally looked at the source of the core samples used in both papers (Lorenz et al. (2006) and Kim et al. (2004)) I found they all came from Kim and Schneider, 2004. So both papers use the same core samples, but use them in different ways to make somewhat different points. These core sample papers remind me some of the papers produced by the Mann and progeny temperature reconstructions.

I was confused by my laziness not to check the Kim graphs with those in Lorenz (2006). I thought they overlapped but on checking back to Lorenz I see that only two graphs were in common (ODP 1019C and 17940-2). Actually the graphs are presented with Kim starting at present and Lorenz starts in the Holocene time. I have to take back my comment that they were from the Lorenz and showing tropic/extratropic differences.

While some of these plots (both from Lorenz and Kim) show almost linear drops or rises from the Holocene to presnt or near present, others do show significantly more oscillations indicating that one may not be able to attribute the lack of resolution to the general method.

This coastal core has a rather complex history. It was brackish & estuarine till 6kBP, so the MWP and the early Holocene may not be directly comparable.

RichardT, could you explain why the 3 distinct periods may not be directly comparable? The graph would imply that the authors of the paper thought differently or at least I could not find their warning of the complications.

Steve M, when I first read the Lorenz paper I found the trend lines confusing to the point of losing important details of the temperature anomalies flucuating over the time period presented. I take it that these graphs with trend lines represent the tropical areas that supposedly went against the Holocene Maximum to present cooling trends in the extratropic areas. Those graphs that appear to extent into the current times all show maximum temperatures that occur before present times. That perhaps is not what Lorenz was attempting to show — thus the trend lines distraction.

http://doi.pangaea.de/10.1594/PANGAEA.438838?format=textfile&charset=ISO-8859-1

They used a hidden form.. had to read the page source.