Notes on the annual and seasonal averages of atmospheric convection and changes during the development of strong El Niños

ERA5 reanalysis data is used to investigate the annual and seasonal average distribution of deep convection in the atmosphere and the changes that occur, especially in the Pacific, during the development of strong El Niños.The results show that, in normal years, the Inter-Tropical Convergence Zone makes the greatest contribution to the vertical flux at low levels of the atmosphere, but the flux is reduced above 500 hPa. The flux in the Island Continent region is initially lower, but it increases with height so that towards the tropopause the Island Continent becomes the dominant convective region. During the northern summer, prior to strong El Niños, a much larger fraction of the ITCZ convection penetrates high in the atmosphere. At the same time the vertical flux in the Island Continent region almost halves.