The future of the low-level jets in northern South America and the Caribbean

Low-level jets are an important moisture transport and dynamic mechanism that influences climate over the Caribbean, Central America, and northern South America. The Caribbean low-level jet (CLLJ) and the western Colombia low-level jet (a.k.a Choco jet) are among the most prominent features of the low-level circulation in the region. In particular, the Choco jet is the result of a combination of several land-ocean-atmosphere regional features, including sea level pressure and surface temperature local gradients, orographic lifting on the Andes, and interactions with other jets, such as the CLLJ. These processes help to explain the high precipitation values experienced over the Colombian Pacific coast, ranging between 8.000 and 13.000 mm per year. Our previous work allowed us to identify the models included in the Coupled Model Intercomparison Project phase 5 (CMIP5) with the best historical simulations of the main features of this low-level jet (seasonal cycle, spatial distribution and location, vertical structure and intensity). Here, we analyze the projections of this low-level jet by the late 21st Century, provided by the CMIP5 models under an RCP8.5 scenario. Although there are several previous studies addressing the CMIP5 simulation and future projections of other low-level jets in America (e.g., CLLJ, Great Plains low-level jet), the future projections of the Choco low-level jet has not been widely evaluated. A coherent representation of this low-level jet in northern South America by the current generation of climate models and an adequate evaluation of their possible future under a global warming scenario is mandatory in order to propose mitigation and adaptation strategies by the communities within the regions most affected by this low-level circulation.