摘要：Abstract. Low-level jets (LLJs) can be defined as wind corridors of anomalously highwind speed values located within the first kilometre of the troposphere.These structures are one of the major meteorological systems in themeridional transport of moisture on a global scale. In this work, we focus onthe southerly Great Plains low-level jet, which plays an important role inthe moisture transport balance over the central United States. The Gulf ofMexico is the main moisture source for the Great Plains low-level jet(GPLLJ), which has been identified as a key factor for rainfall modulationover the eastern and central US. The relationship between moisture transport from the Gulf of Mexico to theGreat Plains and precipitation has been well documented in previous studies.Nevertheless, a large uncertainty still remains in the quantification of themoisture amount actually carried by the GPLLJ. The main goal of this work isto address this question. For this purpose, a relatively new tool, theregional atmospheric Weather Research and Forecasting Model with 3-D watervapour tracers (WRF-WVT; Insua-Costa and Miguez-Macho, 2018) is used togetherwith the Lagrangian model FLEXPART to estimate the load of precipitable wateradvected within the GPLLJ. Both models were fed with data from ERA Interim. From a climatology of jet intensityover a 37-year period, which follows a Gaussian distribution, we select fivecases for study, representing the mean and 1 and 2 standard deviations aboveand below it. Results show that the jet is responsible for roughly70%–80% of the moisture transport occurring in the southern GreatPlains when a jet event occurs. Furthermore, moisture transport by the GPLLJextends to the north-east US, accounting for 50% of the total in areasnear the Great Lakes. Vertical distributions show the maximum of moistureadvected by the GPLLJ at surface levels and maximum values of moisture fluxabout 500m above, in coincidence with the wind speed profile.
