The concentration of atmospheric carbon dioxide at the Japanese Antarctic Station, Syowa

Abstract

Precise and continuous measurements of the atmospheric CO2 concentration have been made at Syowa Station, Antarctica since February 1984. The diurnal CO2 variation was hardly observable throughout the year. The secular CO2 trend was variable with time, showing slow increase in 1984, 1986 and 1988 and rapid increase in 1985 and 1987. The annual CO2 increase was especially large in 1987, which may be related to the 1986/1987 ENSO event. The average rate of annual CO2 increase over the last 5 years was about 1.6 ppmv yr−1. The average seasonal CO2 cycle showed minimum and maximum concentrations in mid‐April and early in October, respectively, and its peak‐to‐peak amplitude was about 1.1 ppmv. The measured seasonal cycle was variable from year to year, but there was no indication of a long‐term increase of the amplitude. It was found that irregular CO2 variations with amplitudes of 0.2 ppmv at most and periods of a few weeks show high correlation with airmass exchange by synoptic scale weather disturbances. The results from Syowa are compared with those from the South Pole and Cape Grim, Tasmania.

Numerical Study of the Relationships between Climate and the Carbon Dioxide Cycle on a Regional Scale

“…The rapid increase of the carbon dioxide concentration (CDC) in 1988 was also observed at other observatories (Nakazawa et al 1991;Conway et al 1994;Lambert et al 1995). The relationship between the variations of the carbon dioxide growth rate and ENSO events has been examined.…”

“…For the most influential factor of the interannual variations, the relationship between the variations of carbon dioxide growth rates and the El Nino/Southern Oscillation (ENSO) events have been examined (Keeling et al 1985;Elliott et al 1991;Nakazawa et al 1991;Nakazawa et al 1993;Conway et al 1994;Winguth et al 1994;Francey et al 1995;Keeling et al 1995;Lambert et al 1995). However, the mechanisms of the relationship between the variations of CDCs and ENSO events have not yet been clarified.…”

“…In connection with the global warming resulting from increases of radiatively active gases in the atmosphere, measurements of the carbon dioxide concentration (CDC) in the atmosphere have been performed at many sites around the world (Nakazawa et al 1991;Nakazawa et al 1993;Conway et al 1994;Lambert et al 1995). Estimates of the carbon dioxide budget are of great importance in taking the proper steps to deal with increased concentrations due to anthropogenic emissions, and in predicting future concentration levels.…”

Cryogenic Air Sampling System for Measurements of the Concentrations of Stratospheric Trace Gases and Their Isotopic Ratios over Antarctica.

“…Indeed, systematic measurements of their concentrations are currently in process at several sites in the Antarctic region and high quality data of the concentrations have been accumulated (Nakazawa et al, 1991;Aoki et al, 1992;Boden et al, 1994). However, the interpretation of observed variations of the concentrations of greenhouse gases is still insufficient .…”

Influence of continental air mass transport on atmospheric CO2 in the western North Pacific

“…[3] Temporal and spatial variations of atmospheric CO 2 have been observed by using ground-based monitoring stations [e.g., Tanaka et al, 1987a;Nakazawa et al, 1991a;Conway et al, 1994], aircraft [e.g., Tanaka et al, 1989;Nakazawa et al, 1991b;Matsueda et al, 2002], and ships [e.g., Tanaka et al, 1987b]. Most of the data from these observations were collected weekly or biweekly using flasks.…”