Shifts in maritime trade routes as a result of Red Sea Shipping Crisis
detected in TROPOMI NO2 data
Abstract
Observations from space-borne spectrometers have been lately used to
quantify shipping emissions of nitrogen oxides (ΝΟΧ). Here we present a
method that enhances the shipping signal of NO2 TROPOspheric MOnitoring
Instrument (TROPOMI) satellite sensor observations in order to assess
the impact of the Red Sea ship attacks on NO2 levels in three important
shipping routes along the Red Sea, the Cape of Good Hope, and the
Gibraltar Strait. Major shipping carriers, sailing usually via the Red
Sea, have responded to the attacks by transiting their fleet around the
African continent. The shipping signal from TROPOMI declines by
~50% in the Red Sea and ~10% in the
Gibraltar Strait while an increase of ~40% is found off
the South African coast between January-March 2024 and the same period
in 2023. These changes correlate well with vessel statistics,
demonstrating the ability to track abrupt changes in NO2 shipping levels
with satellite measurements.