Study on carbon dioxide atmospheric distribution over the Southwest Indian Ocean islands using satellite data: Part 2 –the influence of meteorology and air transportation

Abstract

This investigation is a follow-up to the 3-dimensional distribution analysis of atmospheric CO2 and its surface temporal variation over the Southwest Indian Ocean (SWIO) islands (part 1). Here, we demonstrate the influence of meteorology and the associated air transport on CO2 spatial and vertical distribution determined in part 1. The Hybrid Single-Particle Lagrangian Integrated Trajectories (HYSPLIT) atmospheric model backward trajectories were used to determine the long-range air transport impacting on SWIO islands CO2 atmospheric loading, and to trace the origin of the air masses impacting on the atmosphere of SWIO islands. This study shows that meteorology and long-range air transport results in accumulation or dilution of atmospheric CO2 at various sites on the SWIO islands and this depends on the source region and type of air flow. Long-range air transport from different source regions at the upper atmospheric levels between the 700 and 500 hPa stable layers and the layer above 500 hPa is found to strengthen the inhomogeneity in the vertical distribution of CO2, caused by the decoupling effect of the upper atmosphere stable layers. This long-range air transport is also found to involve intercontinental air transport.