Plate (WDCGG No.22)

Plate 1
Variation of zonally averaged monthly mean CO2 concentrations, deseasonalized concentrations, and growth rates. Zonally averaged concentrations are calculated for each 20-degree zone. Deseasonalized concentrations and growth rates are derived as described in 2.2. Long-term increases and seasonal variations can be seen clearly. Growth rates are high in 1983, 1987/1988, and 1994/1995, but exceptionally low with negative values in 1992.
Plate 2 The same as Plate 1, except that this is for CH4; concentrations, deseasonalized concentrations, and growth rates. Long-term increases and seasonal variations can be seen. Growth rates decreased distinctly from 1980s to 1990s. Growth rates declined to negative values in 1992 in northern high latitudes and to around zero in 1996, but increased largely in 1998 in both hemispheres.

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