Data · dataset · 2026
Water isotopes during the Last Glacial Maximum: New General Circulation Model calculations
Listed in National Center for Atmospheric Research
The application of water isotopes to estimate the glacial-interglacial cycle of temperature (T) assumes the validity of the present-day spatial relationship between Ta and δ¹â¸O in precipitation (δ¹â¸Op) to estimate temporal changes of the temperature at a fixed location.
Description
We explored how and why the spatial relationship between annual mean Ta â δ¹â¸Op is different from the temporal relationship at one location.
Our general circulation-isotope model exhibits a spatial slope of 1.22â°/°C between annual mean temperature at the top of the inversion layer (Ti ) and δ¹â¸Op over Antarctica, comparable to the observed value of 1.25â°/°C from Dahe et al. (1999) and using the Phillpot and Zillman (1970) relationship between surface temperature and the temperature of the inversion layer. Over the Southern Ocean (45°â60°S), local evaporation accounts for 50% of precipitation, and this evaporative flux (mean δ¹â¸Oe of ~â1â°) increases the δ¹â¸O of vapor (mean δ¹â¸Ov of ~â16â°).
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During the Last Glacial Maximum (LGM; 21,000 years ago), the isotopic composition of the vapor near the ice edge (~60°S) is calculated to be similar to the present values because evaporative recharge also accounts for ~50% of the precipitation over the Southern Ocean. As a result, the isotopic composition of vapor during the LGM is close to the present values at the ice edge. The apparent temporal slope over eastern Antarctica is half of the observed spatial slope.
Our LGM experiment estimates an Antarctic mean annual temperature decrease of 13°C at Vostok, much larger than previous estimates. Our experiments with two specifications of LGM sea surface temperatures suggest that the value of the temporal slope is related to the temperature decrease over the Southern Ocean.
Links
Get the data
- Publisher page n2t.org/ark:/85065/d7n29x43 ↗
documentation · download · from data ucar edu
Where it is published
- data.ucar.edu /dataset/water-isotopes-during-the-last-glacial-maximum-new-gen… ↗
National Center for Atmospheric Research dataset page
landing page · from data ucar edu
Catalogue records · 1
- CKAN API data.ucar.edu/api/3/action/package_show?id=0bff6e38-d2fb-4828-aa03-f052b994d… ↗
metadata API · from data ucar edu
Topics
- From keywords
- Earth & Environmental Science · Ocean & Atmospheric Science
- Inferred from text
- Isotope geochemistry 79%
Provenance · 1 source records, 8 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| National Center for Atmospheric Research | 0bff6e38-d2fb-4828-aa03-f052b994d576 | 10 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| concepts[field].anzsrc:field:370303 | enrichment · data ucar edu | taxonomy-embedding@1.1.0 | title+keywords+description (79%) |
| concepts[field].local:field:earth-environmental | mapping · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| concepts[field].local:field:ocean-atmospheric | mapping · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| created_date | source · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| description | source · data ucar edu | connector:data_ucar_edu@1.0.0 | /notes |
| publication_date | source · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| title | source · data ucar edu | connector:data_ucar_edu@1.0.0 | /title |
| updated_date | source · data ucar edu | connector:data_ucar_edu@1.0.0 |