On the effect of cloud microstructure on the polarization characteristics of double scattering lidar return

The work is devoted to remote sensing droplet clouds by coaxial lidar. The results of numerical modeling of the distribution of polarization ellipse parameters of lidar returns in the double-scattering approximation are discussed. It is shown that the polarization state of sounding radiation transforms from a linear (or circular) to the elliptical at the study droplet clouds. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Polarization lidars with conical scanning for retrieving the microphysical characteristics of cirrus clouds

The paper presents the first results of observations of cirrus clouds by polarization lidars with conical scanning, which were developed in Hefei (China) and in Tomsk (Russia). The light scattering matrix of ice crystal particles of cirrus clouds has been calculated for the first by the authors within the framework of the physical optics approximations in the case of conical scanning lidar. It is found that in this case the Mueller matrix consists of ten non-zero elements, four of which are small and can’t be applied to interpret the azimuthal distribution of particle orientation. All the diagonal elements have a strong azimuthal dependence. Among the off-diagonal elements only one element M34 carries additional information for interpreting the azimuthal distribution. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

ERA5 reanalysis for the data interpretation on polarization laser sensing of high-level clouds

Interpreting the results of a high-level clouds (HLCs) lidar study requires a comparison with the vertical profiles of meteorological quantities. There are no regular radiosonde measurements of vertical profiles of meteorological quantities in Tomsk. The nearest aerological stations are several hundred kilometers away from the lidar and perform radiosonde measurements only a few times a day, whereas lidar experiments are performed continuously throughout the day. To estimate meteorological conditions at the HLC altitudes, we propose to use the ERA5 reanalysis. Its reliability was tested by comparing with the data from five aerological stations within a radius of 500 km around Tomsk. A labeled database of the lidar, radiosonde, and ERA5 data (2016–2020) for isobaric levels 1000–50 hPa was created. The temperature reconstruction error over the entire altitude range was characterized by an RMSE of 0.8–2.8 ◦C, bias of 0–0.9, and Corr ~1. The accuracy of the relative vertical profiles (RMSE 25–40%, Bias 10–22%, and Corr <0.7) and specific humidity (RMSE 0.2–1.2 g/kg, Bias ~0 g/kg, and Corr ~0) at the HLC altitudes were unsatisfying. The ERA5 data on wind direction and speed for the HLC altitudes were promising

On the effect of cloud microstructure on the polarization characteristics of double scattering lidar return

The work is devoted to remote sensing droplet clouds by coaxial lidar. The results of numerical modeling of the distribution of polarization ellipse parameters of lidar returns in the double-scattering approximation are discussed. It is shown that the polarization state of sounding radiation transforms from a linear (or circular) to the elliptical at the study droplet clouds. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Verification of ERA5 reanalysis data for the interpretation of lidar investigation of high-level clouds

Interpretation of the data from lidar studies of high-level clouds requires information on the vertical profiles of meteorological quantities. The nearest aerological stations to Tomsk are located at about 250 km away from the city and launch radiosondes only twice a day. The ERA5 reanalysis was considered as a source of vertical profiles, which provides higher spatial and temporal resolution. It is compared with the aerological data, and the possibility of its using was evaluated in this research

Polarization lidars with conical scanning for retrieving the microphysical characteristics of cirrus clouds

The paper presents the first results of observations of cirrus clouds by polarization lidars with conical scanning, which were developed in Hefei (China) and in Tomsk (Russia). The light scattering matrix of ice crystal particles of cirrus clouds has been calculated for the first by the authors within the framework of the physical optics approximations in the case of conical scanning lidar. It is found that in this case the Mueller matrix consists of ten non-zero elements, four of which are small and can’t be applied to interpret the azimuthal distribution of particle orientation. All the diagonal elements have a strong azimuthal dependence. Among the off-diagonal elements only one element M34 carries additional information for interpreting the azimuthal distribution. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Neutrino mass ordering determination through combined analysis with JUNO and KM3NeT/ORCA

The determination of neutrino mass ordering (NMO) is one of the prime goals of several neutrino experiments. KM3NeT/ORCA and JUNO are two next-generation neutrino oscillation experiments both aiming at addressing this question. ORCA determines the NMO by probing Earth matter effects on the oscillation of atmospheric neutrinos in the GeV energy range. JUNO, on the other hand, is sensitive to the NMO by investigating the interference effects of fast oscillations in the reactor electron antineutrino spectrum at medium baseline. This poster presents the potential of determining the NMO through a combined analysis of JUNO and ORCA data. When measuring the Δm312 with a wrong ordering assumption, the best-fit values are different between the two experiments. This tension, together with good constraints on the Δm312 measurement by both experiments, enhances the combined NMO sensitivity beyond the simple sum of their sensitivities. The analysis shows that 5σ significance is reachable in less than 2 years of data taking with both experiements for true normal neutrino mass ordering assuming current global best-fit values of the oscillation parameters, while 6 years will be needed for any other parameter set