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A new look at the Law Dome proxy series provides some decidedly non-PC data on Antarctic temperatures.
[h=2]New Antarctic Temperature Reconstruction[/h]Nov 20, 2017 – 11:24 PM
Stenni et al (2017), Antarctic climate variability on regional and continental scales over the last 2000 years, was published pdf this week by Climate of the Past. It includes (multiple variations) of a new Antarctic temperature reconstruction, in which 112 d18O and dD isotope series are combined into regional and continental reconstructions. Its abstract warns that “projected warming of the Antarctic continent during the 21st century may soon see significant and unusual warming develop across other parts of the Antarctic continent [besides the peninsula]”, but no Steigian red spots of supposedly unprecedented warming.
Long-time CA readers will be aware of my long-standing interest in Antarctic ice core proxies, in particular, the highly resolved Law Dome d18O series. One of my first appearances in Climategate emails was a request for Law Dome data to Tas van Ommen in Australia, who immediately notified Phil Jones in Sauron’s Tower of this disturbance in the equilibrium of Middleearth. Jones promptly consulted the fiercest of his orcs, who urged that the data be withheld as follows: ” HI Phil, Personally, I wouldn’t send him [McIntyre] anything. I have no idea what he’s up to, but you can be sure it falls into the “no good” category.” I’ve discussed incidents involving Law Dome data on several occasions in the past. This is what the data looked like as of 2004: elevated values in the early first millennium, declining up to and including the 20th century.
Law Dome – Holocene Perspective
Recently, I’ve commented on many occasions on the benefits of looking at proxy data in a Holocene (10000 year context) rather than just the last 2000 years. A longer perspective permits one to see Milankovitch factors at work and this is true for Law Dome d18O as well. Although Law Dome d18O analyses were carried out nearly 20 years ago, results have been archived only for the deglacial period (~20000-9000 BP) and for the last 2000 years – shown in the graphic below. The inset shows (unarchived) Law Dome dD values over the Holocene, available only in a panel in a 2000 survey of Antarctic cores (Masson et al 2000). Though the data is frustratingly (and pointlessly) incomplete, the story is clear: d18O values were very low in the Last Glacial Maximum, then increased fairly steadily for 10000 years reaching a maximum ~9-10000 BP (in the early Holocene), then declined in the past 9000 years. Modern values are neither as high as in the early Holocene, nor as low as the Last Glacial Maximum. Variation over the past two millennia is relatively modest. . . .
[h=2]New Antarctic Temperature Reconstruction[/h]Nov 20, 2017 – 11:24 PM
Stenni et al (2017), Antarctic climate variability on regional and continental scales over the last 2000 years, was published pdf this week by Climate of the Past. It includes (multiple variations) of a new Antarctic temperature reconstruction, in which 112 d18O and dD isotope series are combined into regional and continental reconstructions. Its abstract warns that “projected warming of the Antarctic continent during the 21st century may soon see significant and unusual warming develop across other parts of the Antarctic continent [besides the peninsula]”, but no Steigian red spots of supposedly unprecedented warming.
Long-time CA readers will be aware of my long-standing interest in Antarctic ice core proxies, in particular, the highly resolved Law Dome d18O series. One of my first appearances in Climategate emails was a request for Law Dome data to Tas van Ommen in Australia, who immediately notified Phil Jones in Sauron’s Tower of this disturbance in the equilibrium of Middleearth. Jones promptly consulted the fiercest of his orcs, who urged that the data be withheld as follows: ” HI Phil, Personally, I wouldn’t send him [McIntyre] anything. I have no idea what he’s up to, but you can be sure it falls into the “no good” category.” I’ve discussed incidents involving Law Dome data on several occasions in the past. This is what the data looked like as of 2004: elevated values in the early first millennium, declining up to and including the 20th century.
Law Dome – Holocene Perspective
Recently, I’ve commented on many occasions on the benefits of looking at proxy data in a Holocene (10000 year context) rather than just the last 2000 years. A longer perspective permits one to see Milankovitch factors at work and this is true for Law Dome d18O as well. Although Law Dome d18O analyses were carried out nearly 20 years ago, results have been archived only for the deglacial period (~20000-9000 BP) and for the last 2000 years – shown in the graphic below. The inset shows (unarchived) Law Dome dD values over the Holocene, available only in a panel in a 2000 survey of Antarctic cores (Masson et al 2000). Though the data is frustratingly (and pointlessly) incomplete, the story is clear: d18O values were very low in the Last Glacial Maximum, then increased fairly steadily for 10000 years reaching a maximum ~9-10000 BP (in the early Holocene), then declined in the past 9000 years. Modern values are neither as high as in the early Holocene, nor as low as the Last Glacial Maximum. Variation over the past two millennia is relatively modest. . . .
