The polar mesospheric cloud dataset of the Balloon Lidar Experiment BOLIDE

Abstract

Abstract. The Balloon Lidar Experiment (BOLIDE) observed polar mesospheric clouds (PMC) along the Arctic circle between Sweden and Canada during the balloon flight of PMC Turbo in July 2018. The purpose of the mission was to study small-scale dynamical processes induced by the breaking of atmospheric gravity waves by high-resolution imaging and profiling of the PMC layer. The primary measured variable of the lidar soundings is the time- and range-resolved volume backscatter coefficient β. These data are available at high resolution of 20 m and 10 s (Kaifler, 2021, https://zenodo.org/record/5722385). This document describes how we calculate β from the BOLIDE photon count data and balloon floating altitude. We compile information relevant for the scientific exploration of this dataset, including statistics, mean values and temporal evolution of parameters like PMC brightness, altitude and occurrence rate. Special emphasis is given to the stability of the gondola pointing, and the effect of resolution on the signal-to-noise ratio and thus the detection threshold of PMC. PMC layers were detected during 49.7 h in total, accounting for 36.8 % of the 5.7 days flight duration and a total of 178924 PMC profiles at 10 s resolution. Up to the present, published results from subsets of this dataset include the evolution of small-scale vortex rings, distinct Kelvin-Helmholtz instabilities and two pronounced mesospheric bores. The lidar soundings reveal a wide range of responses of the PMC layer to larger-scale gravity waves and breaking gravity waves including accompanying instabilities that await scientific analysis.

Signatures of gravity wave-induced instabilities in balloon lidar soundings of polar mesospheric clouds

“…The Balloon Lidar Experiment BOLIDE is a Rayleigh backscatter lidar designed to operate onboard a stratospheric longduration balloon at an altitude of ∼40 km at polar latitudes (Kaifler et al, 2020). During the 6-day flight of PMC Turbo along the Arctic circle from Sweden to Canada in July 2018 almost 50 h of high-resolution PMC soundings were recorded (Kaifler et al, 2022;Fritts et al, 2019). PMC are detected relative to a standard atmosphere density profile as described in detail by Kaifler et al (2022).…”

“…During the 6-day flight of PMC Turbo along the Arctic circle from Sweden to Canada in July 2018 almost 50 h of high-resolution PMC soundings were recorded (Kaifler et al, 2022;Fritts et al, 2019). PMC are detected relative to a standard atmosphere density profile as described in detail by Kaifler et al (2022). In short, the atmospheric return signal from the 28 • off-zenith tilted 4.2 W laser beam was collected by a 0.5 m diameter receiving telescope and detected by an avalanche photodiode operated in a single-photon counting mode.…”

“…Volume backscatter coefficients of PMC, β, follow an exponential distribution (Berger et al, 2019;Kaifler et al, 2022). It is therefore convenient to plot and analyze β on a logarithmic scale.…”

Multi‐Scale Kelvin‐Helmholtz Instability Dynamics Observed by PMC Turbo on 12 July 2018: 1. Secondary Instabilities and Billow Interactions

“…PMC Turbo instruments and preliminary analysis methods are described in greater detail in two PMC Turbo instrument papers (Kaifler et al., 2020; Kjellstrand et al., 2020), and in the C. B. Kjellstrand (2021) and C. Geach (2020) theses, as well as by Kaifler et al. (2022a, b, submitted to ESSD).…”