Reconciliation of Temperature-Depth Profiles in Polar Ice Sheets with Past Surface Temperatures Deduced from Oxygen-Isotope Profiles

Abstract

ABSTRACT. In ves tigati ons of isotopi c a nd tempera ture pro fil es in polar ice sh ee ts were mostly carri ed out inde p endently of one a nother until 19 73 whe n a workshop d ealing with both topics was held in Ca mbridge. Studies of temperature profi les show the a pproximate validity of theoreti call y d e rived tempera ture d istributio n s for stead y-state models of ice sh eets, whi le other a na lyses h elp to determin e d e partures from the s tead y sta te . The rev iew gives some idea of the d egree of accuracy of various solution s arising from studies of the hea t Aow a nd temperature distributio n of ice sheets. Much of this knowledge is directly applicable to interpre tatio n of isotopic profi les if a direct co rrespond ence be tween m ean isotopi c (5 values and mea n a nnual te mpe ra tures can be es tablished. The paper therefor e reviews vari ous methods of comparing IJ values and te mpe ra tures, and shows tha t for cen t ra l regions of polar ice sh ee ts a reaso n a b ly consistent rel ationship b e tween these fa ctors does exist. RESUME . Compatibilite des profils tempiratures-prqfondeurs dans les calottes polaires avec les temperatures passees de la surface telles qu'on les deduit des profils de teneur en isotope de l'oxy gene.Les rech erch es sur les profils en iso topes e t e n temperatures dans les calottes po laires ont sunout ete m e n ees independem m e nt l'un e de l'autre jusqu 'en ZUSAMMENFASSUNG. ZusammenJiihnmg von T emperatur-T ie.fen-Profilen ill polaren E isdecken und JnlherellOberjlachentel7lperaturen, hergeleitet aus Sauerstoifisotopell-Profilell. Untersu chungen von l so to p en-und T emperaturpro fil e n in polaren Eisdecken wurd en m e ist unabha ngig vonein a nder durchgefuhrt, bis im J ahre 1973 e in Se minar uber beide V e rfa hren in Cambridge a bgehalten wurde. Studien d er T e mperaturprofi le zeigen di e a nge n a h erte Gultigke it theoretisch a bgele iteter T emperaturve rteilungen fur stationare Mod ell e von E isd ecken, wahrend an d ere Analysen z ur Bes timmung d e r Abweichungen vom stationa ren Zusta nd b e itragen. D ie Zusammenstellung gibt ei n e n Eindruck von d el' Genauigkeit verschied ener Ansatze fur die Verteilung des Warm e Ausses und del' T e mpe ra tur in Eisdecken. Viele dieser Einsichten sind fur die D eutung vo n I sotopen-Profilen unmittelba r a nwe ndbar, wenn ein dire kte r Zusammenhang zwischen den mittle ren iso to pisch en (5-vVerten und del' mittl e re n Jahres tempera tur fes tzustellen ist. Die Arbeit diskuti ert d a h er verschi ed ene M ethode n d es Vergleich s von (5-Werten und T empera turen und weist nach , dass im Zentralb e re ich von polare n Eisd ecken zwisch e n di esen beid en Faktoren eine a usreich e nd konsistente Bez iehung besteht.] NTROD UCTION

Depth–age and temperature prediction at Dome Fuji station, East Antarctica

“…However, spatial and temporal estimates of the slope C T are different, and the latter appear consistently (up to 50%) lower and dependent on the time-scale under consideration (Jouzel and others, 1997). Deep-borehole temperature profiles provide information on past climate changes that is important for calibrating the isotopic paleothermometer (Robin, 1976; Cuffey and others, 1995; Johnsen and others, 1995; Salamatin and others, 1998b). the main difficulty arising here is that the non-stationary temperature–depth distributions in ice sheets result from the past surface temperature variations δT s that cannot be directly identified with δT i in general.…”