Phys.org July 31, 2024 Despite common background La Niña conditions, Australia was very dry in November 2020 and wet in November 2021. Researchers in Australia examined the El Niño Southern Oscillation, Indian Ocean Dipole, Southern Annular Mode and Madden Julian Oscillation, but they did not find obvious clues. They found that the absence (in 2020) or presence (in 2021) of an enhanced thermal wind and subtropical jet over the Australian continent contributed to the rainfall anomalies. In November 2021 the warm sea surface temperatures led to an enhanced meridional temperature gradient and subtropical jet over Australia. The enhanced jet provided […]
Tag Archives: Global weather
‘New El Niño’ discovered south of the equator
Phys.org July 22. 2024 An international team of researchers (India, Japan) simulated Interannual sea surface temperature (SST) variations in the subtropical-midlatitude Southern Hemisphere which are often associated with a circumpolar wavenumber-4 (W4) pattern. They found that incoming climatological solar radiation goes into a thinner (thicker) mixed layer, the shallower (deeper) mixed layer promotes surface warming (cooling) leading to positive (negative) SST anomalies, developing the SST-W4 pattern during austral summer. Due to the temperature difference between the mixed layer and the water below the mixed layer, anomalous latent heat fluxes, and disappearance of the overlying atmospheric W4 pattern cause the decay […]