New Numeric Data Packages from CDIAC

Atmospheric Carbon Dioxide Mixing Ratios from the NOAA Climate Monitoring and Diagnostics Laboratory Cooperative Flask Sampling Network, 1967-1993

NDP-005, ORNL/CDIAC-73 (1996)

The Climate Monitoring and Diagnostics Laboratory (CMDL) has measured CO₂ in air samples collected in glass flasks from a global network of sites since the late 1970s and from two stations since 1967. Whole-air samples are always collected in pairs once or twice a week. The samples are cryogenically dried during analysis. The CO₂ mixing ratios of those samples are measured by nondispersive infrared analysis and are reported in the World Meteorological Organization's X93 mole-fraction scale.

The flasks and the sampling and handling methods have been developed over time, and these improvements have produced a marked increase in the percentage of sample pairs agreeing within 0.5 ppm. When overlapped sampling was conducted at several sites, no offsets from the new flasks or sampling equipment were observed except for an offset of -0.3 ppm with the introduction of 3-L flasks at Barrow and Cape Kumukahi.

These measurements constitute the most geographically extensive, carefully calibrated, internally consistent atmospheric CO₂ data available. Because the database documents the global CO₂ distribution for the past several decades, it has been and can be used for many carbon-cycle- and global-change-related studies. Analysis of the database shows a long-term increase in atmospheric CO₂ mixing ratios since the late 1960s. Growth rates for individual sites and the global growth rate vary with time, and the database shows a hemispheric gradient that ranges from 2 to 5 ppm.

This NDP contains the monthly atmospheric CO₂ mixing ratios and CO₂ measurements obtained by the CMDL. Records of measurements at 40 land-based sites and of shipboard measurements covering 14 latitude bands in the Pacific Ocean and South China Sea and dating back to 1967 are provided. Approximately 60,000 individual flask CO₂ measurements are given, including those not considered indicative of regional background tropospheric conditions. Each measurement is flagged according to the degree it satisfies the CMDL data-selection criteria.

The NDP has 163 data files, totalling 8.5 MB. The data are provided on a variety of media, including 9-track magnetic tape, IBM- or Macintosh-formatted floppy diskettes, 8-mm tape, and 0.25-in. tape cartridges. This NDP may also be obtained from CDIAC's World Wide Web home page or anonymous FTP area or from the NOAA/CMDL anonymous FTP area on the Internet. The database may be subsetted or reformatted for users upon request.

United States Historical Climatology Network (U.S. HCN) Monthly Temperature and Precipitation Data

D. R. Easterling, T. R. Karl, E. H. Mason, P. Y. Hughes, and D. P. Bowman, National Oceanic and Atmospheric Administration, National Climatic Data Center, Asheville, North Carolina

NDP-019/R3, CDIAC/ORNL-87 (1996)

This data package constitutes the third revision of the United States Historical Climatology Network (U.S. HCN). This revision contains monthly temperature and precipitation data for 1221 stations in the contiguous United States. These data represent the best available data from the United States for analyzing long-term climate trends on regional scales. The data for most stations extend through December 31, 1994, and a majority of the station records are serially complete for at least 80 years. Unlike many regional data sets that have been used in past climate studies, these data have been adjusted to remove biases introduced by station moves, instrument changes, time-of-observation differences, and urbanization effects.

The NDP includes 27 data files, consisting of supporting data files, a descriptive file, and computer-access codes. The entire database takes 355 MB of disk space, with the largest file being 16 MB. The data are available on 9-track magnetic tape, 8-mm tape, and 0.25-in. tape cartridges. This database may also be obtained by accessing CDIAC's anonymous FTP area on the Internet. Because of the importance of this NDP, a World Wide Web home page has been developed specifically for this data; it is located at /ndps/ ndp019r3.html.

Total Carbon Dioxide, Hydrographic, and Nitrate Measurements in the Southwest Pacific During Austral Autumn, 1990: Results from the NOAA/PMEL CGC-90 Cruise

Marilyn F. Lamb and Richard A. Feely, Pacific Marine Environmental Laboratory, Seattle, Washington
Lloyd Moore and Donald K. Atwood, Atlantic Oceanographic and Meteorological Laboratory, Miami, Florida

NDP-052, ORNL/CDIAC-84 (1995)

The collection of data during the austral autumn of 1990 was designed to investigate the increase in chlorofluorocarbons and carbon dioxide in the thermocline waters since the previous expedition in 1984. Data were collected along two legs: Leg 1 ran along 170°W from 15°S to 60°S and then angled northwest toward New Zealand across the Western Boundary Current. Leg 2 included a reoccupation of some stations between 30°S and 15°S on 170°W and measurements from 15°S to 5°N along 170°W. The total CO₂ concentration in seawater (TCO₂), salinity, temperature, and nitrate were measured at 63 stations along the cruise track. In addition, potential density and potential temperature were calculated from the measured variables.

The NDP consists of two oceanographic-data files (one listing the station locations, sampling dates, and sounding bottom depths for each station; the other giving the hydrographic, carbon dioxide, and nitrate data from the 63 stations), two FORTRAN 77 routines to read and print the data files, and a readme file (a detailed description of the cruise network and of the data and FORTRAN files), all totalling about 192 kB. The data are available from CDIAC's WWW home page or anonymous FTP area, on floppy diskette, and on 9-track magnetic tape.

Rattlesnake Mountain Observatory (46.4°N, 119.6°W) Multispectral Optical Depth Measurements: 19791994

N. R. Larson, Pacific Northwest Laboratory, Richland, Washington
J. J. Michalsky, Atmospheric Sciences Research Center, Albany, New York
B. A. LeBaron, Utah Bureau of Air Quality, Salt Lake City, Utah

NDP-053, ORNL/CDIAC-85 (1995)

Solar irradiance of the atmosphere was measured with a scanning photometer at the Rattlesnake Mountain Observatory in eastern Washington. It measures the attenuation of direct solar radiation at wavelengths suitable for monitoring variations in the total optical depth of the atmosphere. Rayleigh scattering and ozone absorption were subtracted to obtain total-column aerosol optical depths. The total aerosol optical depths were further decomposed into tropospheric and stratospheric components by calculating a robustly smoothed mean background optical depth for each wavelength from data obtained during periods of low stratospheric aerosol loading and subtracting that from the total aerosol optical depths. These estimates of the stratospheric aerosol optical depth may be used to monitor the long-term effects of volcanic eruptions on the atmosphere.

The NDP documentation describes the methods used for acquiring each variable, details of file contents and formats, and the restrictions and limitations of the data. The computer files consist of eight flat ASCII data files, one FORTRAN and one SAS^TM; retrieval file, and a descriptive file, all totalling 0.92 MB. The ASCII data files contain total optical depths for the 428-nm, 486-nm, 535-nm, 785-nm, and 1010-nm wavelength bands; total-column aerosol optical depths for each wavelength; and smoothed-background tropospheric aerosol optical depths. All files are available on floppy diskette or on the Internet via CDIAC's anonymous FTP and World Wide Web server.

Carbon Dioxide, Hydrographic, and Chemical Data Obtained in the Central South Pacific Ocean (WOCE Sections P17S and P16S) During the TUNES-2 Expedition of the R/V Thomas Washington, JulyAugust 1991

T. Takahashi, J. G. Goddard, S. Rubin, D. W. Chipman, and S. C. Sutherland, Columbia University, Lamont-Doherty Earth Observatory, Palisades, New York
C. M. Goyet, Woods Hole Oceanographic Institute, Woods Hole, Massachusetts

NDP-054, ORNL/CDIAC-86 (1995)

Total carbon dioxide (TCO₂), total alkalinity (TALK), and discrete partial pressure of CO₂ (pCO₂) were measured during the Research Vessel (R/V) Thomas Washington TUNES Leg 2 Expedition in the central South Pacific Ocean. Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in Papeete, Tahiti, French Polynesia, on July 16, 1991, and returned to Papeete on August 25, 1991. WOCE Zonal Sections P17S along 135°W and P16S along 150°W were completed during the 40-day expedition, and 97 hydrographic stations were occupied. The hydrographic and chemical measurements made along WOCE Sections P17S and P16S included pressure, temperature, salinity, and oxygen measured by conductivity, temperature and depth sensor; bottle salinity; oxygen; phosphate; nitrate; nitrite; silicate; CFC-12; CFC-11; TCO₂; TALK; and pCO₂ measured at 20°C.

The NDP consists of two oceanographic data files (653 and 7 kB), two FORTRAN 77 data-retrieval-routine files (1 and 2 kB), a readme file (60 kB), and printed documentation that describes the contents and format of all files and the procedures and methods used to obtain the data. The files are available on CDIAC's WWW home page and its anonymous FTP area; they are also available on 9-track tape, floppy diskette, 8-mm tape, and 0.25-in. tape cartridges.