[Parameters: Topic='PALEOCLIMATE', Term='ICE CORE RECORDS', Variable_Level_1='ISOTOPES']
Law Dome d18O data 2100BP to 1996 as 4-year averagesEntry ID: ASAC_757_LD_d18O
Abstract: LD2.1ky-grid4y - Law Dome d18O data 2100BP (Present=2000AD) to 1996 as 4-year averages.
Data set used in:
Jones, P.D. and M.E. Mann, Climate Over Past Millennia, Rev. Geo. 42(2), RG2002, doi:10.1029/2003RG000143,
Mann, M.E. and Jones, P.D. Global Surface Temperatures over the Past Two Millennia, GRL 30(15), 1820, doi: 10.1029/2003GL017814
Records for this site are in active development: ... check with firstname.lastname@example.org for information on updated or improved Law Dome isotope data sets.
Ages older than 700BP estimated from flow-model constrained by layer-thickness data (similar to Morgan et al., J. Glaciol, 43(143), 3-10, 1997).
Estimated error at 2ky BP on the order of a few decades.
Ages younger than 700BP from layer counting. Estimated error +/-1 year at 700BP scaling to absolute (zero error) from 193-0BP.
d18O values in permille. Approximate accuracy of individual measurements 0.1 permille, but each datum presented here is an integration of between 4 and 40 individual measurements, dependent upon age and sampling scheme.
For conversion to temperature, values of ~0.2-0.3 permille/degreeC are deduced from short-term comparisons. Longer term comparison of seasonal amplitude (van Ommen and Morgan, JGR, 102(D8), 1997) indicates conversion coefficient of 0.44 permille/degree C. Spatially derived conversion coefficients are on the order of 0.6-0.7 permille/degree C, but are unlikely to be appropriate.
Note on annual phasing:
A year for the purposes of averaging of the resolved-annual cycles, is by convention marked by the isotope maximum. Thus, calendar year 1994, for example, starts with the isotope peak in the Austral summer of 1993/1994 and concludes at the 1994/1995 peak. Studies show that on the average, the isotope peak occurs around January 10 (van Ommen and Morgan, JGR, 102(D8), 9351-9357, 1997).
This work was completed as part of ASAC/AAS project 757.
This data set description is a member of a collection. The collection is described in
Start Date: 2010-04-08Stop Date: 2010-04-08
Paleo Temporal Coverage
Paleo Start Date: 2100 YBP
Paleo Stop Date: 1996
Quality This is an older dataset that is actively being updated. It is therefore recommended that users contact the investigator before using these data to check if a more up-to-date version is available.
Access Constraints These data are publicly available for download from the provided URL.
Use Constraints This data set conforms to the PICCCBY Attribution License
Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_757... when using these data.
Data Set Progress
Distribution Media: HTTP
Distribution Size: 4 kb
Distribution Format: text
Role: TECHNICAL CONTACT
Phone: +61 3 6226 2981
Email: tas.van.ommen at utas.edu.au
Antarctic Climate and Ecosystems CRC University of Tasmania Grosvenor St
City: Sandy Bay
Province or State: Tasmania
Postal Code: 7005
Role: DIF AUTHOR
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: dave.connell at aad.gov.au
Australian Antarctic Division 203 Channel Highway
Province or State: Tasmania
Postal Code: 7050
Jones, P.D. and M.E. Mann (2004), Climate Over Past Millennia, Reviews of Geophysics, 42, 2, 42, doi:doi:10.1029/2003RG000143, RG2002
Mann, M.E. and Jones, P.D. (2003), Global Surface Temperatures over the Past Two Millennia, Geophysical Research Letters, 30, 15, 1820, doi:doi: 10.1029/2003GL017814
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2010-04-08
Last DIF Revision Date: 2014-01-10