How δ¹⁸O in an ice core records temperature
PAPER IV — CHEMISTRY · QUESTION 31 OF 32
In plain terms: The free official archive of the ice-core measurements the question turns on.
The question as set
Explain how δ¹⁸O in an ice core records temperature, and state the assumptions the palaeothermometer hides.
The question in Paper IV · Its section on the reference page
The question in context
This is question 31 of the 32 set in Paper IV — Chemistry of The Truly Hardest Exam in the World, the examination of The College of All Minds. In the College’s subject index it is filed under Climate and the Earth system and Measurement and error. Like every question of the College, it carries three references of record, verified live at publication and described twice — technically, and in plain terms — so the ground can be judged before it is walked. The response required is an argument, not a survey, of at most three thousand words, as technical as the question demands and no more.
The references of record
Ice core palaeoclimatology — the data archive
The proxy series themselves: δ¹⁸O and δD records with their chronologies and accumulation corrections.
In plain terms: The free official archive of the ice-core measurements the question turns on.
The isotope thermometer explained: Rayleigh distillation, the spatial slope, and the assumption that it may be read temporally.
In plain terms: The free scholarly primer on how an isotope ratio becomes a temperature — and what has to be assumed on the way.
The correction literature: source-region effects, ice-sheet elevation change, and calibration against borehole temperatures.
In plain terms: The free open journal where the palaeothermometer’s hidden assumptions are argued and revised.