Phys.org November 4, 2024
Poleward water vapor transport in the midlatitudes mainly occurs in meandering filaments of intense water vapor transport, spanning thousands of kilometers long and hundreds of kilometers wide and moving eastward. The water vapor filaments, known as atmospheric rivers (ARs), can cause extreme wind gusts, intense precipitation, and flooding along densely populated coastal regions. Many recent studies about ARs focused on the statistical analyses of ARs, but a process-level understanding of ARs remains elusive. A team of researchers in the US (Argonne National Laboratory, University of Chicago) showed that ARs are streams of air with enhanced vapor kinetic energy (VKE) and derived a governing equation for Integrated VKE to understand what contributes to the evolution of ARs. They found that ARs grow mainly because of potential energy conversion to kinetic energy, decay largely owing to condensation and turbulence, and the eastward movement was primarily due to horizontal advection of VKE. According to the researchers their VKE framework complements the integrated vapor transport framework, which is popular for identifying ARs but lacks a prognostic equation for understanding the physical processes… read more. Open Access TECHNICAL ARTICLE
Atmospheric river (AR) frequency… Credit: Nature Communications volume 15, Article number: 9428, 04 November 2024