IAGOS estimates of climate-process costs for trans-Atlantic flights

IAGOS, or the In-service Aircraft for a Global Observing System project, is a European Infrastructure project consisting of scientific measurement packages attached to commercial aircraft. Operating since 1994, this programme provides a unique long-timeseries dataset of flight data across the globe, with thousands of flights per year providing a strong base for statistical studies.

Here, we use flight times derived from IAGOS metadata to quantify the role of the El Nino - Southern Oscillation (ENSO), the Quasi-Biennial Oscillation, the solar cycle and the North Atlantic Oscillation (NAO) on trans-Atlantic flight times. We do this both by subsetting the data in various ways and via regression methods. This allows us to statistically assess the effects of these large-scale atmospheric-dynamical processes on trans-Atlantic flight times. We also calculate the additional costs associated with these effects in terms of both carbon dioxide emissions and fuel costs, allowing us to understand how climate processes drive them.

Depending on season and direction of flights, we show that these four climate indices can explain as much as 1/3 of the total variance in trans-Atlantic flight times. At a flight-time level and particularly in winter, the NAO dominates flight times and is the most important factor in one-way fuel costs: flights at peak NAO+ can be as much as 83 minutes longer than the equivalent flight at peak NAO- when crossing the Atlantic. However, at a whole-dataset level, ENSO is shown to be much more important in driving net round-trip costs. We further estimate that the monthly cost of these four climate indices can be as high as 100 kT of additional CO2 or USD 20 million at 2023 flight volumes and fuel prices.