ICE GENESIS: Synergetic Aircraft and Ground-Based Remote Sensing and In Situ Measurements of Snowfall Microphysical Properties

Billault–Roux, Anne-Claire; Grazioli, Jacopo; Delanoë, Julien; Jorquera, Susana; Pauwels, Nicolas; Viltard, Nicolas; Martini, Audrey; Mariage, Vincent; Gac, Christophe Le; Caudoux, Christophe; Aubry, Clémantyne; Bertrand, Fabrice; Schwarzenböeck, Alfons; Jaffeux, Louis; Coutris, Pierre; Febvre, Guy; Pichon, Jean Marc; Dezitter, Fabien; Gehring, Josué; Untersee, Aude; Calas, Christophe; Ventura, Jordi Figueras i; Vié, Benoît; Peyrat, Adrien; Curat, Valentin; Rebouissoux, Simon; Berne, Alexis

doi:10.1175/bams-d-21-0184.1

Cited by 5 publications

(5 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This reveals the presence of a partial melting layer related to the onset of the warm front, during which a warm air mass with slightly positive temperatures overlays, then replaces, a cooler air mass with negative temperatures (e.g., Emory et al, 2014). This temperature inversion is confirmed by aircraft measurements of air temperature (Billault-Roux et al, 2023b).…”

Section: Radar Timeseriesmentioning

confidence: 54%

“…In-situ measurements of snowfall were conducted at various altitude levels by the scientific aircraft Safire-ATR42, equipped with a extensive set of probes as listed in Billault-Roux et al (2023b) and, in particular, three different optical array probes which are used in this work. The high-volume precipitation spectrometer (HVPS) (resp.…”

Section: In-situ Aircraft Measurementsmentioning

confidence: 99%

See 1 more Smart Citation

Distinct secondary ice production processes observed in radar Doppler spectra: insights from a case study

Billault–Roux

Georgakaki²,

Gehring

et al. 2023

Preprint

View full text Add to dashboard Cite

Abstract. Secondary ice production (SIP) has an essential role in cloud and precipitation microphysics. In recent years, substantial insights were gained into SIP by combining experimental, modeling, and observational approaches. Remote sensing instruments, and among them meteorological radars, offer the possibility to study clouds and precipitation in extended areas over long time periods, and are highly valuable to understand the spatio-temporal structure of microphysical processes. Multi-modal Doppler spectra measured by vertically-pointing radars reveal the coexistence, within a radar resolution volume, of hydrometeor populations with distinct properties; as such, they can provide decisive insight into precipitation microphysics. This paper leverages polarimetric radar Doppler spectra as a tool to study the microphysical processes that took place during a snowfall event on 27 January 2021, in the Swiss Jura Mountains, during the ICE GENESIS campaign. A multi-layered cloud system was present, with ice particles sedimenting through a supercooled liquid water (SLW) layer in a seeder-feeder configuration. Building on a Doppler peak detection algorithm, we implement a peak labeling procedure to identify the particle type(s) that may be present within a radar resolution volume. With this approach, we can visualize spatio-temporal features in the radar time series that point to the occurrence of distinct mechanisms at different stages of the event. By focusing on three 30-minute phases of the case study, and by using the detailed information contained in the Doppler spectra, together with dual-frequency radar measurements, aircraft in-situ images, and simulated profiles of atmospheric variables, we narrow down the possible processes which can be responsible for the observed signatures. Depending on the availability of SLW and the droplet sizes, on the temperature range, and on the interaction between the liquid and ice particles, various SIP processes are identified as plausible, with distinct fingerprints in the radar Doppler spectra. A simple modeling approach suggests that the ice crystal number concentrations likely exceed typical concentrations of ice nucleating particles by one to four orders of magnitude. While a robust proof of occurrence of a given SIP mechanism cannot be easily established, the multi-sensor data provides various independent elements each supporting the proposed interpretations.

show abstract

Section: Radar Timeseriesmentioning

confidence: 54%

Section: In-situ Aircraft Measurementsmentioning

confidence: 99%

Distinct secondary ice production processes observed in radar Doppler spectra: insights from a case study

Billault–Roux

Georgakaki²,

Gehring

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Liquid attenuation is then simulated using the water dielectric constant model by Rosenkranz (2014) and assuming that liquid droplets absorb in the Rayleigh regime, using Eq. (5.18) in Bohren and Huffman (2008). This approach relies on the assumption that one continuous liquid layer is present between the liquid base indicated by the ceilometer and the cloud top.…”

Section: Ka-and W-band: Gas and Liquid Attenuation Correctionmentioning

confidence: 99%

“…The addition of polarimetric and multifrequency capabilities can further expand the spectrum of obtainable fingerprints. Linear depolarization and dual polarization observations can, in fact, provide strong constraints for the shape and concentration of ice particles (Oue et al, 2015;von Terzi et al, 2022;Billault-Roux et al, 2023). At the same time, millimeter-radar observations at multiple wavelengths provide robust constraints for the size of ice particles: the ratio of the radar reflectivities measured at two separate wavelengths, named the dual-wavelength ratio (DWR), can be related to the characteristic size of the ice particle population (Hogan et al, 2000;Dias Neto et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Low-level mixed-phase clouds at the high Arctic site of Ny-Ålesund: a comprehensive long-term dataset of remote sensing observations

Chellini,

Gierens,

Ebell

et al. 2023

Earth Syst. Sci. Data

View full text Add to dashboard Cite

Abstract. We present a comprehensive quality-controlled 15-month dataset of remote sensing observations of low-level mixed-phase clouds (LLMPCs) taken at the high Arctic site of Ny-Ålesund, Svalbard, Norway. LLMPCs occur frequently in the Arctic region and extensively affect the energy budget. However, our understanding of the ice microphysical processes taking place in these clouds is incomplete. The dual-wavelength and polarimetric Doppler cloud radar observations, which are the cornerstones of the dataset, provide valuable fingerprints of ice microphysical processes, and the high number of cases included allows for the compiling of robust statistics for process studies. The radar data are complemented with thermodynamic retrievals from a microwave radiometer, liquid base height from a ceilometer, and wind fields from large-eddy simulations. All data are quality controlled, especially the cloud radar data, which are accurately calibrated, matched, and corrected for gas and liquid-hydrometeor attenuation, ground clutter, and range folding. We finally present an analysis of the temperature dependence of Doppler, dual-wavelength, and polarimetric radar variables, to illustrate how the dataset can be used for cloud microphysical studies. The dataset has been published in Chellini et al. (2023) and is freely available at: https://doi.org/10.5281/zenodo.7803064.

show abstract

“…Microphysical processes in the melting layer, such as the melting, merging, falling, and breaking of hydrometeors, play an important role in exploring rainfall mechanisms and quantitatively assessing rainfall [16,29,30]. Hence, the characteristics of bright bands and their implication in microphysical processes in the melting layer have been attracting considerable attention from observational, theoretical, and modeling studies since the advent of radar meteorology [22,[31][32][33].…”

Section: Introductionmentioning

confidence: 99%

An Observation of Precipitation during Cooling with Ka-Band Cloud Radar in Wuhan, China

Mao,

Huang,

Fang

et al. 2023

Remote Sensing

View full text Add to dashboard Cite

Exploiting their sensitivity to cloud droplets and small raindrops, Ka-band cloud radar observations are used to investigate weak stratiform precipitation over Wuhan during cooling on 16–17 February 2022. During cooling, the surface temperature drops by about 8 °C with the lowest value less than 0 °C because of the strong cold air from the north. The cold air lifts the warm and humid air transported by the southeasterly and southwesterly winds, causing thick stratiform clouds and persistent weak precipitation. The Ka-band radar captures the full process of stratiform cloud occurrence; light rain and then mixed rain and snow; and the characteristics of clouds and precipitation at each stage due to its fine sensitivity to small hydrometeors, whereas the reanalysis data alone cannot capture the transition to the mixed rain and snow regime, which can cause dangerous freezing rain or sleet on the ground. Hence, a detailed analysis of cooling and cold surges and their hazards to society, and their reproduction in numerical predictions, needs to use high-sensitivity radar data as much as possible.

show abstract

ICE GENESIS: Synergetic Aircraft and Ground-Based Remote Sensing and In Situ Measurements of Snowfall Microphysical Properties

Cited by 5 publications

References 42 publications

Distinct secondary ice production processes observed in radar Doppler spectra: insights from a case study

Distinct secondary ice production processes observed in radar Doppler spectra: insights from a case study

Low-level mixed-phase clouds at the high Arctic site of Ny-Ålesund: a comprehensive long-term dataset of remote sensing observations

An Observation of Precipitation during Cooling with Ka-Band Cloud Radar in Wuhan, China

Contact Info

Product

Resources

About