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Tristan Abbott

Publications and source records attributed to Tristan Abbott.

2 recordsLinked to original sources

Efficacy of Scalable Airline-led Contrail Avoidance

Contrails account for a large portion of aviation's contribution to anthropogenic climate change. Navigational contrail avoidance is a promising solution to mitigate the warming caused by contrails. Prior trials testing navigational contrail avoidance have relied on bespoke integrations of contrail forecasts into airline operations. Here, we use a randomized control trial to test the feasibility of dispatcher-led contrail avoidance integrated into standard flight planning operations using a workflow that scales to an airline's entire network. We validated the efficacy of this intervention using satellite imagery and an automated flight-contrail attribution algorithm. Using this system, we observed an 11.6% reduction in contrail formation rate for the 1232 flights marked as eligible for contrail avoidance (intent-to-treat) relative to the flights in the control group (p = 0.011). In the 112 flights that flew contrail avoidance as planned (per-protocol flights), we observed a 62.0% lower contrail formation rate relative to the flights in the control group (p < 0.001). No statistically significant difference in fuel usage was observed between the two groups.

physics.ao-ph

Comparing Convective Self-Aggregation in Idealized Models to Observed Moist Static Energy Variability near the Equator

Idealized convection-permitting simulations of radiative-convective equilibrium (RCE) have become a popular tool for understanding the physical processes leading to horizontal variability of tropical water vapor and rainfall. However, the applicability of idealized simulations to nature is still unclear given that important processes are typically neglected, such as lateral vapor advection by extratropical intrusions, or interactive ocean coupling. Here, we exploit spectral analysis to compactly summarize the multi-scale processes supporting convective aggregation. By applying this framework to high-resolution reanalysis data and satellite observations in addition to idealized simulations, we compare convective-aggregation processes across horizontal scales and data sets. The results affirm the validity of the RCE simulations as an analogy to the real world. Column moist static energy tendencies share similar signs and scale-selectivity in convection-permitting models and observations: Radiation increases variance at wavelengths above 1,000km, while advection damps variance across wavelengths, and surface fluxes mostly reduce variance between 1,000km and 10,000km.

physics.ao-ph