Initial measurements of CO2 concentrations (1530 to 1940 AD) in air occluded in the GISP 2 Ice Core from central Greenland

Initial measurements of CO2 in the air of bubbles in the GISP 2 (Greenland Ice Sheet Project 2) ice core were performed using a dry extraction technique and tunable diode laser absorption spectroscopy. The record spans the years 1530 to 1940, and includes part of the little ice age. Absolute dating of the air was obtained from the location of the 14CO2 bomb peak in the bubble air, relative dating from the seasonal variations of H218O and electro-conductivity. The results for preindustrial times indicate constant atmospheric CO2 levels of 280±5 ppmv between 1530 and 1810 AD. Thereafter the concentrations rise rather abruptly. The record smoothly connects to the direct atmospheric observations from Mauna Loa.

[1]  E. Mosley‐Thompson,et al.  The Little Ice Age as Recorded in the Stratigraphy of the Tropical Quelccaya Ice Cap , 1986, Science.

[2]  H. Oeschger,et al.  CO2 record in the Byrd ice core 50,000–5,000 years bp , 1988, Nature.

[3]  H. Oeschger,et al.  Past atmospheric composition and climate, gas parameters measured on ice cores , 1978, Nature.

[4]  D. Raynaud,et al.  An Antarctic ice core reveals atmospheric CO2 variations over the past few centuries , 1985, Nature.

[5]  H. Oeschger,et al.  Biospheric CO2 emissions during the past 200 years reconstructed by deconvolution of ice core data , 1987 .

[6]  H. Craig,et al.  Methane: The record in polar ice cores , 1982 .

[7]  H. Oeschger,et al.  Enclosure of Air During Metamorphosis of Dry Firn to Ice , 1985, Annals of Glaciology.

[8]  A new dry extraction system for gases in ice , 1984 .

[9]  C. Lorius,et al.  Ice-core record of atmospheric methane over the past 160,000 years , 1990, Nature.

[10]  B. Stauffer,et al.  Age difference between polar ice and the air trapped in its bubbles , 1984, Nature.

[11]  H. Oeschger,et al.  CO2 measurements from polar ice cores: more data from different sites , 1991 .

[12]  H. Oeschger,et al.  Comparison of CO2 measurements by two laboratories on air from bubbles in polar ice , 1983, Nature.

[13]  J. A. Matthews.  ‘Little Ice Age’ palaeotemperatures from high altitude tree growth in S. Norway , 1976, Nature.

[14]  C. Lorius,et al.  Vostok ice core provides 160,000-year record of atmospheric CO2 , 1987, Nature.

[15]  John A. Eddy,et al.  The Maunder Minimum , 1976, Science.

[16]  H. Oeschger,et al.  CO2 measurements on 1-cm3 ice samples with an IR laserspectrometer (IRLS) combined with a new dry extraction device , 1982 .

[17]  H. Oeschger,et al.  Evidence from polar ice cores for the increase in atmospheric CO2 in the past two centuries , 1985, Nature.

[18]  U. Siegenthaler,et al.  Stable-Isotope Ratios and Concentration of CO2 in Air from Polar Ice Cores , 1988, Annals of Glaciology.

[19]  D. Etheridge,et al.  Evidence of changing concentrations of atmospheric CO2, N2O and CH4 from air bubbles in Antarctic ice , 1986, Nature.

[20]  D. Donahue,et al.  AMS carbon-14 dating of ice: progress and future prospects , 1990 .

[21]  M. Legrand,et al.  Polar ice evidence that atmospheric CO2 20,000 yr BP was 50% of present , 1980, Nature.

[22]  H. Oeschger,et al.  Ice core sample measurements give atmospheric CO2 content during the past 40,000 yr , 1982, Nature.

[23]  Michael M. Herron,et al.  Firn Densification: An Empirical Model , 1980, Journal of Glaciology.

[24]  H. Oeschger,et al.  Increase of Atmospheric Methane Recorded in Antarctic Ice Core , 1985, Science.