Figure 8: Composite maps of water vapor column-integrated abundance and partitioning index. For the partitioning index, values higher than 0.5 (in green) indicate that more than 50% of the water vapor column is confined below 5 km, while lower values (in brown) indicate that water vapor is more evenly dispersed with altitude. The data has been averaged in bins of 2° latitude, 2° Ls and 4° longitude.
4.4 Deviances from the MCD
The synergistically retrieved column abundances and vertical confinement shown in Figure 8 contain significant differences from the MCD prior estimates. Figure 9 illustrates the deviance of the synergy from the MCD estimates as a relative difference with the MCD abundances as reference values (\(rel.diff.\ =\ \frac{SYN-MCD}{\text{MCD}}\)) , such that a deviance of 0 means the synergy and the MCD are equal, and instances where the synergy gives the larger values are positive. The relationship between the retrieved and prior CIA is shown in the left column, and of the retrieved and prior PI in the right column.
Figure 9 shows that, on the whole, the synergy has a tendency to retrieve column abundances lower than the corresponding MCD prior values. The sublimation peak in early summer (around Ls=110°), which controls most of the total atmospheric water vapor throughout the year on the whole planet, is significantly smaller than the MCD estimate, yet agrees somewhat better with the MCD than the surrounding observations. The total water content in the tropical fall is a good indicator of meridional transport of vapor from northern polar regions (Navarro et al., 2014), and this is where the model and synergy are most similar.