Precise and continuous measurements of atmospheric CO 2 concentration have been continued at Syowa Station (69°00′S, 39°35′E), Antarctica since February 1984. Diurnal CO 2variation was hardly observable throughout the year. The secular CO 2 trend was variable with time, showing slow increase in 1984, 1986 and 1988 and rapid increase in 1985 and 1987. The annual CO 2 increase was remarkable, especially in 1987, which may have been related to the 1987 ENSO event. The average rate of annual CO 2 increase over the last 5 years was about 1.6 ppmv yr -1. The average seasonal CO 2 cycle showed minimum and maximum concentrations in mid-April and in early October, respectively. Its peak-to-peak amplitude was about 1.1 ppmv for the period 1984-1988. The seasonal cycle was variable from year to year, but there was no indication of long-term amplitude increase. It was found that irregular CO 2 variations with amplitudes of about 0.2 ppmv and with periods of a few tens of days have high correlation with air mass exchange by synoptic scale weather disturbances.
|Number of pages||16|
|Publication status||Published - 1997 Dec 1|
ASJC Scopus subject areas
- Aquatic Science
- Earth and Planetary Sciences(all)