Hypothesis of the lightning initiation on the arrays of large hydrometeors are in the consideration. There is no agreement about the form the hydrometeors that could be the best for the lightning initiation from the thundercloud. Artificial charged water aerosol clouds of the positive or negative polarity could help investigate the possible influence of the hydrometeor form on the peculiarities...

The melting layer (ML) is a significant phenomenon in weather radar observations. It consists of initially frozen hydrometeors falling into air below the 0C isotherm (freezing level) where they start melting. The radar echoes from melting hydrometeors differ from those from rain droplets as well as from frozen hydrometeors, and ML is observed as the radar bright band. The ML is a complex atmosp...

Scanning polarimetric W-band radar data were evaluated for the purpose of identifying predominant ice hydrometeor habits. Radar and accompanying cloud microphysical measurements were conducted during the Storm Peak Laboratory Cloud Property Validation Experiment held in Steamboat Springs, Colorado, during the winter season of 2010/11. The observed ice hydrometeor habits ranged from pristine and...

Clouds can significantly impact trace chemical distributions in the troposphere and the chemical composition of precipitation. Clouds affect chemical distributions through convection of air and hydrometeors containing trace chemicals. They also provide a multiphase environment for chemical phase changes and reaction. Due to the large vertical motions and turbulence of strong convective cloud sy...

Investigation of the discharges from the artificial charged water aerosol clouds in presence of the arrays of the model hydrometeors could help to receive the new data about the peculiarities of the return stroke formation between the thundercloud and the ground when the large volumes of the hail particles participate in the lightning discharge initiation and propagation stimulation. Artificial...

The aggregation of volcanic ash particles within the eruption column of explosive eruptions has been observed at many volcanoes. It influences the residence time of ash in the atmosphere and the radiative properties of the umbrella cloud. However, the information on the processes leading to aggregate formation are still either lacking or very incomplete. We examine the fate of ash particles thr...

The maximum measured electric fields in thunderclouds are an order of magnitude less than the fields required for electric breakdown of the air. One explanation for lightning initiation in these low fields is that electric breakdown first occurs at the surfaces of raindrops where the ambient field is enhanced very locally due to the drop geometry . Laboratory experiments [Crabb & Latham, 1974] ...