Ability to quantify coherent turbulent structures in the convective boundary layer using thermodynamic profiling instruments

Abstract

Water vapor mixing ratio data from the Raman lidar and Atmospheric Emitted Radiance Interferometer (AERI) are analyzed toward inferring the presence of organized, three‐dimensional, turbulent features within convective boundary layers (CBLs). The Raman lidar and AERI instruments provide unique, high‐quality data sets, from 200‐m to ∼3‐km altitude at ≤1‐min temporal resolution profiles of water vapor. CBLs under the influence of solar heating for two fair‐weather days over the Atmospheric Radiation Measurement (ARM) Central Facility near Lamont, Oklahoma, during the International H20 Project 2002 (IHOP_2002), and 1 day during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers (CRYSTAL)‐Florida Area Cirrus Experiment (FACE) 2002 experiment, are evaluated. This research provides a means of inferring the presence of coherent, convectively driven circulation (momentum) signatures exclusively from high‐temporal resolution water vapor profiles. Spectral and statistical analysis of Raman lidar water vapor‐time series reveal the passage of coherent turbulent structures, including horizontal convective rolls (HCRs), within the CBL over the ARM site at ∼8 and 12 min intervals for 2 days during IHOP_2002. AERI data collected during CRYSTAL‐FACE also indicate similar structures, with meteorological conditions on this day also dictating the presence of cloud streets over the AERI (every 12 and 28 min). Radiosonde, satellite, and ceilometer analyses provide information about the favored stability and CBL cloud patterns, as well as a check on our spectral analysis. Evidence within the perturbation water vapor time series from these two instruments is well correlated with HCRs and other cumulus patterns seen in 1 km resolution GOES visible satellite imagery.