Plains Elevated Convection At Night (PECAN)
Description:
The Plains Elevated Convection At Night (PECAN) special collection contains articles related to the PECAN field campaign, conducted over the Great Plains during June-July 2015. This campaign assembled a rich array of observations from lower-tropospheric profiling systems, mobile radars and mesonets, and aircraft, in order to better understand nocturnal mesoscale convective systems (MCSs) and their relationship with the stable boundary layer, the low-level jet (LLJ), and atmospheric bores. More specifically, PECAN aimed to study (a) pristine nocturnal convection initiation and the initial upscale growth of deep convection; (b) the mechanisms in which the mesoscale environment modulates the initiation, structure, propagation, and evolution of bores, solitons, and other trapped wave disturbances, and the inherent role of these disturbances in the maintenance of nocturnal MCSs; (c) the structure and evolution of the nocturnal LLJ; (d) the dynamical and microphysical structure of nocturnal MCSs; and (e) the prediction of nocturnal CI, MCSs, and, more generally, the diurnal cycle of warm season precipitation. Papers in this collection cover such topics as: instruments used for the first time or in a novel way in PECAN; the microphysics and/or the dynamics of MCSs and associated severe weather aspects; the dynamics of MCS outflow boundaries, such as density currents, bores, and solitons; the initiation of nocturnal deep convection; dynamics of the Great Plains low-level jet; nocturnal boundary-processes in the presence of a LLJ; numerical simulations of any of the above-listed meteorological topics at a range of scales, with the purpose of improving understanding as well as predictability; novel data assimilation projects and observing system simulation experiments using PECAN data, especially its mesoscale network of lower-tropospheric profiling systems.
PECAN was funded primarily by NSF, with additional funding from NOAA, NASA, DOE, and the Canadian Natural Sciences and Engineering Research Council.
Collection organizers:
David Parsons, University of Oklahoma
Bart Geerts, University of Wyoming
Tammy M. Weckwerth, NCAR
Conrad L. Ziegler, NOAA National Severe Storms Lab
David D. Turner, NOAA National Severe Storms Lab
Plains Elevated Convection At Night (PECAN)
Differential Reflectivity Calibration and Antenna TemperatureAbstract
Temporal differential reflectivity 
Abstract
Temporal differential reflectivity
Validation of a Water Vapor Micropulse Differential Absorption Lidar (DIAL)Abstract
A water vapor micropulse differential absorption lidar (DIAL) instrument was developed collaboratively by the National Center for Atmospheric Research (NCAR) and Montana State University (MSU). This innovative, eye-safe, low-power, diode-laser-based system has demonstrated the ability to obtain unattended continuous observations in both day and night. Data comparisons with well-established water vapor observing systems, including radiosondes, Atmospheric Emitted Radiance Interferometers (AERIs), microwave radiometer profilers (MWRPs), and ground-based global positioning system (GPS) receivers, show excellent agreement. The Pearson’s correlation coefficient for the DIAL and radiosondes is consistently greater than 0.6 from 300 m up to 4.5 km AGL at night and up to 3.5 km AGL during the day. The Pearson’s correlation coefficient for the DIAL and AERI is greater than 0.6 from 300 m up to 2.25 km at night and from 300 m up to 2.0 km during the day. Further comparison with the continuously operating GPS instrumentation illustrates consistent temporal trends when integrating the DIAL measurements up to 6 km AGL.
Abstract
A water vapor micropulse differential absorption lidar (DIAL) instrument was developed collaboratively by the National Center for Atmospheric Research (NCAR) and Montana State University (MSU). This innovative, eye-safe, low-power, diode-laser-based system has demonstrated the ability to obtain unattended continuous observations in both day and night. Data comparisons with well-established water vapor observing systems, including radiosondes, Atmospheric Emitted Radiance Interferometers (AERIs), microwave radiometer profilers (MWRPs), and ground-based global positioning system (GPS) receivers, show excellent agreement. The Pearson’s correlation coefficient for the DIAL and radiosondes is consistently greater than 0.6 from 300 m up to 4.5 km AGL at night and up to 3.5 km AGL during the day. The Pearson’s correlation coefficient for the DIAL and AERI is greater than 0.6 from 300 m up to 2.25 km at night and from 300 m up to 2.0 km during the day. Further comparison with the continuously operating GPS instrumentation illustrates consistent temporal trends when integrating the DIAL measurements up to 6 km AGL.
