Law Dome Ice Core Oxygen Isotope Averages Over Two Millennia

LD2.1ky-grid4y provides a 2,100-year record of oxygen isotope ratios (d18O) from the Law Dome ice core in Antarctica, averaged into 4-year intervals. The dataset, developed by researchers including P.D. Jones and M.E. Mann, was used in key paleoclimate studies and last updated in April 2010. Each data point integrates between 4 and 40 individual ice core measurements, with age estimates derived from flow modeling and layer counting.

Use Cases

• Reconstructing past Antarctic temperature anomalies by applying a conversion coefficient (e.g., 0.44 per mille/degree C) to the d18O time-series.
• Calibrating and validating global climate models using the high-resolution 4-year averaged d18O record spanning 2100 BP to 1996.
• Analyzing the timing of climate events by examining the phasing of the annual isotope maximum, which conventionally marks the start of a calendar year in this dataset.
• Assessing age estimation uncertainty by comparing flow-model derived ages (for >700 BP) with layer-counted ages (for <700 BP) within the record.

Strengths

• Covers a 2,100-year temporal range from 2100 BP to 1996 AD.
• High data density with each 4-year average integrating 4 to 40 individual d18O measurements.
• Age estimates for younger sections (<700 BP) have an error of +/-1 year, scaling to zero error from 193-0 BP.

Limitations

• Dataset is temporally stale, with no updates recorded since 2010.
• Estimated age error at 2000 BP is on the order of a few decades.
• The appropriate d18O-to-temperature conversion coefficient (ranging from ~0.2 to 0.7 per mille/degree C) requires careful selection for analysis.

Provenance

Source

Australian Antarctic Data Centre (AU_AADC), associated with ASAC/AAS project 757.

Collection Method

Derived from the Law Dome ice core; d18O measurements averaged into 4-year intervals, with ages determined by flow modeling (older section) and layer counting (younger section).

Time Range

2100 years before present (BP, where present=2000 AD) to 1996 AD.

Freshness

Last updated on 2010-04-08; update frequency is unknown.

Geography

Law Dome, Antarctica.