Dust-infused Baroclinic Cyclone Storm Clouds: the Evidence, Meteorology, and Implications

Desert mineral dust is a critical yet still poorly understood component of atmospheric composition, weather and climate. The regional and global implications of mineral dust in the climate system are the focus of long-standing and continuing scientific exploration. Widespread global distribution of desert dust from point sources is well known yet there remain fundamental uncertainties regarding the pathway from the desert floor to the free troposphere. Here we will show that a recurrent pathway for mineral dust into the uppermost troposphere routinely involves passage through an extratropical baroclinic cyclone's cloud system. The evidence derives from a synergistic use of satellite-based, multi-spectral nadir-image data and lidar. We find what we refer to as a dust-infused baroclinic storm (DIBS), which exhibits peculiar cirrus cloud-top reflected and emitted radiance from the UV through thermal IR, involving positive UV absorbing aerosol index, muted visible reflectivity, visible cumuliform texture, and systematically intense visible lidar backscatter on a synoptic scale. Proof that the DIBS is microphysically impacted by storm-scale dust infusion is the occurrence of anomalously large daytime 3.9-11