Science Daily January 31, 2019
Researchers in the UK observed that existing precipitation is enhanced locally on spatial scales from a few kilometers to several tens of kilometers. The precipitation intensity in these localized areas was 6‐14 times higher than the background large‐scale precipitation rate. Surface observations and dual‐polarization radar data indicate that snowflakes within the ice portion of the falling precipitation in the intensification regions are larger and more isotropic than in the surrounding precipitation. There appears to be an increase in the ice particle number concentration within the intensification region. The observed events were linked to arriving or departing air traffic. According to the researchers the mechanism responsible for intensification is aircraft‐produced ice particles boosting the aggregation growth of snowflakes…read more. Open Access TECHNICAL ARTICLE
A radar station at Kerava, Finland, recorded a trail of heightened precipitation–the yellow streak to the left–on the aircraft approach path to Helsinki-Vantaa airport (EFHK) in March 2009. Credit: AGU/Journal of Geophysical Research: Atmospheres