The new historical flood of 2021 in the Amazon River compared to major floods of the 21st century: Atmospheric features in the context of the intensification of floods

As documented in the previous major floods of the 21st century (2009 and 2012), the 2021 flood also occurs under La Niña conditions in the central equatorial Pacific; however, in 2012 flood conditions are observed early over northwestern Amazon tributaries, since October 2011. In addition, warm conditions are observed over the tropical Atlantic during December 2020–March 2021. In accordance with this feature, increased atmospheric water vapor is imported by easterly winds from this oceanic region into the northern Amazon Basin.