Abstract.
From NASA’s Atmospheric Tomography (ATom) mission, we calculate the
average production/loss of O3 and CH4for 10s air parcels along profiling transects through the
Pacific/Atlantic Oceans for four seasons. We find photochemically hot
air masses on all scales from 2 to 2000 km. Tropical production of
O3 is high (~2 ppb/day) throughout the
ATom profiles (0–12 km). In the
Eastern Pacific we find large coherent air masses of extremely high
reactivities in August (monsoonal) and May (biomass burning).
The tropics dominate the
O3 and CH4 budgets.
Sensitivity analysis identifies
only five critical species (NOx, O3,
CH4, CO, and H2O) responsible for
driving the budgets. Sensitivity analysis shows large
2nd-order effects for coupled perturbations,
indicating that 1st-order sensitivities cannot simply
be added. Feedback analysis
indicates a slower-than-expected timescale for decay of
O3 perturbations. ATom data shows how global
tropospheric chemistry is constructed from a myriad of fine and large
scales.