Ice core data

The estimated response time of CaCOa compensation, on the order of a few thousand years, is a serious problem because the ice core data do not show such a long delay in atmospheric CO2 changes with respect to temperature changes. Such a long delay may preclude CaCOa compensation as an important process in predicting atmospheric CO2 in the next few centuries. 

Siegenthaler, U. and Oeschger, H. (1987). Biospheric CO2 emissions during the past 200 years reconstructed by deconvolution of ice core data, Tellus 39B. 

Fig. 18-11 Records of atmospheric CO2 in Antarctica for the past 1000 years. Open circles are ice-core data from Law Dome, on the coast of east Antarctica (Etheridge et al., 1996). Plus signs are direct measurements of CO2 in air samples collected monthly at the South Pole (NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, Colorado).

Fig. 9.7 Isotope records of abrupt climate change at the Younger-Dryas Preboreal transition 11,600 years BP taken from Greenland ice core data. The 8lsO, 815N2, and 840Ar isotopic records are plotted from top to bottom (Reprinted from Grachev, A. M. and Severinghaus, J. P. Quat. Sci. Rev. 24, 513 (2005), copyright 2005, with permission from Elsevier)...

Fig. 3.47 Dansgaard-Oeschger events in the time period from 45000 to 30000 years before present from GRIP and NGRIP ice core data (http //en.wiMpedia.0rg/wiId/Image Grip-ngrip-dol 8-...

Haan, D., P. Martinerie, and D. Raynaud, Ice Core Data of Atmospheric Carbon Monoxide over Antarctica and Greenland during the Last 200 Years, Geophys. Res. Lett, 23, 2235-2238 (f996). 

Figure 14.13 shows C02 concentrations measured in ice cores at the Byrd Station in Antartica from 5000 years before the present (bp) to 40,000 years bp (Anklin et al., 1997). The use of ice core data for elucidating atmospheric composition is discussed by Delmas (1992) and in more detail in Section E.l. As seen in Fig. 14.13, atmospheric C02 concentrations about 5000 years ago were only 280 ppm. (Note that interpretation of such ice core data must be carried out with care since there is evidence that in some cases, C02 can be produced in the ice from decomposition of carbonate e.g., see Smith et al., 1997.)... 

The first major link between the indirect effects of aerosol particles and climate is whether there has been an increase in particles and in CCN due to anthropogenic activities. As discussed in Chapter 2, anthropogenic emissions of particles and of gas-phase precursors to particles such as S02 have clearly increased since preindustrial times, and it is reasonable that CCN have also increased. Ice core data provide a record of some of the species that can act as CCN. Not surprisingly, sulfate and nitrate in the ice cores have increased substantially over the past century (Mayewski et al., 1986, 1990 Laj et al., 1992 Fischer et al., 1998). For example, Figure 14.43 shows the increases in sulfate and nitrate since preindustrial times in an ice core in central Greenland (Laj et al., 1992). Sulfate has increased by 300% and nitrate by 200%. This suggests that sulfate and nitrate CCN also increased, although not necessarily in direct proportion to the concentrations in the ice core measurements. 

The five warmest years for which there are surface temperature records have all been since 1990 (Jones et al., 1998), with the most recent year for which there are data (at the time of writing), 1997, being the warmest in the past century (see Kerr, 1998, and references therein). Mann et al. (1998) have used a variety of indirect indicators for temperature (e.g., ice core data see later) over the past 600 years in the Northern Hemisphere and report that mean annual temperatures for three of the eight years up to and including 1995 are higher than any since 1400 A.D. 

J. R. Petit, et al Vostok Ice Core Data for 420,000 Years, NOAA/NGDC Paleoclimatolo-gy Program, IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series 2001-076, Boulder, CO, 2001. 

Fawcett P. J., Agustdottir A. M., Alley R. B., and Shuman C. A. (1997) The Younger Dryas termination and north Atlantic deepwater formation insight from climate model simulations and Greenland ice core data. Paleocanography 12, 23-38. 

Martinerie P., Brasseur G. P., and Granier C. (1995) The chemical composition of ancient atmospheres a model study constrained by ice core data. J. Geophys. Res.-Atmos. 100, 14291-14304. 

The Holocene spans the past 11,500 years. Much of the Holocene time scale is obtained from Greenland and Antarctic ice-core data, from stratigraphic pollen records, and other records of floral, faunal, and landscape changes. Records younger then 45,000 years are also within the range of radiocarbon dating. The recent Holocene is the historic period when some written records are available and finally the past century or so, the contemporary period, where directly measured climatic data are available for comparison. 

Chappellaz, J., and Jouzel, J., 1992, Vostok Ice Core Data Set IGBP PAGESAVorld Data Center-A for Paleoclimatology, Data Contribution Series 92-018. 

Atmospheric CO2 concentrations and global temperatures are strongly correlated, as established by ice core data. 

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