The South America Low-level jet: Form, Variability and Subseasonal Forcings

The South America Low-level Jet (SALLJ) is a climatological feature with a critical role in the spatiotemporal distribution of precipitation in South America. While previous studies have focused on the mechanisms and variability of the SALLJ in the central Andes (i.e., southeast Peru, Bolivia, and Paraguay), the occurrence of the low-level jet in the eastern slopes of the northern Andes (i.e., northeast Peru, Colombia, and Venezuela) and its linkages to the central region have been less explored. ERA5 reanalysis during November-March, 1979-2021 are used to investigate the form, variability and subseasonal forcings of the SALLJ along the entire eastern Andes. A new method identifies the spatial extent of northerly low-level jets in the eastern Andes and categorizes the jets into: central, northern and simultaneous occurrences. This presentation will discuss the different manifestations of eastern Andes low-level jets and transitions among the different types. Additionally, the associations between different SALLJs and precipitation will be shown. Lastly, equatorial and subtropical subseasonal forcings of the SALLJ will be discussed.