| dc.description.abstract | Over the past 40+ years, cold front vertical structure has been studied for the
purpose of increased understanding of convection initiation and aviation safety. Traditional
scanning radars tend to not be well-suited for observing small-scale features due to low
spatial resolution and slow volume coverage patterns (VCPs). While some
previous studies have achieved high spatial or temporal resolution, this study is unique in that
cold front vertical structure is observed at both high spatial and temporal resolution without
any mechanical movement using the Atmospheric Imaging Radar (AIR). This mobile,
X-band, phased array radar offers relatively high spatial (0.5 degree in elevation, 30 m in
range) and temporal (300 ms) resolution while in range-height indicator (RHI) scanning mode.
Because the AIR is an imaging radar, electromagnetic energy is transmitted in a wide fan
beam pattern in elevation, allowing for use of digital beamforming to create simultaneous receive beams. This offers an additional advantage over traditional, pencil-beam radars:
because all receive beams are simultaneous, differential vertical advection can be distinguished from
temporal evolution. The ability of the AIR to obtain these simultaneous RHIs without
any mechanical movement allows for unique analysis of cold front structure which
would otherwise be difficult or impossible. Features such as Kelvin-Helmholtz Instabilities,
low-level mass transport (referred to as feeder flow), transverse jet oscillations, and regions
of heightened spectrum width will be analyzed and discussed in this study, which aims to
improve understanding of small-scale, rapidly evolving features behind the leading edge of a cold front. | en_US |
