Fig. S8.

Onset-relative composite time series of area-mean $\delta$D of water vapor in the free troposphere (750 to 348 hPa) (A) and the ABL (surface–825 hPa) (B) based on TES satellite retrievals from ascending ($\sim$13:30 local time) and descending ($\sim$01:30 local time) satellite overpasses. Data in B are shown for ascending overpasses only because TES is not sufficiently sensitive to ABL $\delta$D during descending overpasses (see also Materials and Methods and Fig. S9). The evolution of ABL $\delta$D over the tropical Atlantic (0–10°N, 30–55°W) is also shown for reference. Uncertainty bounds include statistical and measurement uncertainties propagated from individual TES measurements.