Basic Data Analysis for Time Series with R

20 VOSTOK ICE CORE DATA

20.1 SOURCE OF THE DATA

The Vostok ice core data is stored at the National Oceanic and Atmospheric Administration at these locations:

• ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/vostok/deutnat.txt
• ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/vostok/co2nat.txt. ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/vostok/dustnat.txt

The original source (updated 11/2001) for this data is due to Petit et al. (1999).

The first file listed above contains a second column that is the estimated age of the reading and the last (fourth) column that is the temperature as deviations from a baseline level. The units for temperature are Celsius. A header in the original file explains each column in a lot more detail. Some of the first few rows of data in the file are presented in Table 20.1.

TABLE 20.1 Temperature Data (“Vostok temps.txt” in the Vostok Folder)

Depth_corrected	Ice_age(GT4)	deut	deltaTS
0	0	−438	0.00
1	17	−438	0.00
2	35	−438	0.00
…
10	190	−435.8	0.36
11	211	−443.7	−0.95
12	234	−449.1	−1.84
13	258	−444.6	−1.09
14	281	−442.5	−0.75, etc.

This data is in the Vostok folder from the data disk and is denoted “Vostok temps.txt.” Obviously, the file must be brought into R using read.table() (with header = T), not scan().

The second files from NOAA contains the ice core CO₂ measurements in ppmv (parts per million by volume). There are only two columns, the first is the estimated age and the ...