Linear Analysis of Moisture Transport Due to Baroclinic Waves

In this talk, the effects of rainfall speed and meridional/vertical moisture gradients on the meridional moisture transport are examined in the context of mid-latitude baroclinic waves. These effects are investigated using an idealized quasi-geostrophic model with simplified microphysics that give rise to a moist Eady problem. Specifically, single-phase dynamics are considered for three fundamental moisture regimes: unsaturated, saturated with no rainfall speed, and saturated with rainfall speed. It is shown that the meridional moisture flux, as a function of height, has a mid-tropospheric maximum in the case of no rainfall speed and a maximum in the lower troposphere or at the surface for sufficiently large values of rainfall speed. These results for different rainfall speed values are then discussed in the context of meridional moisture transport in observational data.