Validation and traceability of miniaturized multi-parameter cluster of radiosondes used for atmospheric observations

Year
2023
Document type
Article
Authors
Shahbozbek Abdunabiev, Andrea Merlone, Chiara Musacchio, Miryam Paredes, Eros Pasero, Daniela Tordella
Source

Arxiv preprint, submitted to Measurement, Elsevier

https://dx.doi.org/10.48550/arxiv.2301.09928

In this work we designed and developed a cluster of light expendable radiosondes that can float passively inside warm clouds to study their micro-physical processes. This involves the tracking of both saturated and unsaturated turbulent air parcels. The aim of this new kind of observation system is to obtain Lagrangian statistics of the intense turbulence inside warm clouds and of the lower intensity turbulence that is typical of the air surrounding such clouds. Each radiosonde in a cluster includes an electronic board, which is mounted onto a small, biodegradable balloon filled with a mixture of helium and air. The cluster is able to float inside clouds for a few hours and to measure air temperature, pressure, humidity and the associated position, velocity, acceleration and magnetic field readings of each radiosonde along their trajectory.

Free flying cluster of miniaturized radiosondes for multi-parameter atmospheric fluctuation observations

Year
2023
Document type
Other
Authors
Shahbozbek Abdunabiev, Mina Golshan, Antonella Abba, Daniela Tordella

18th European Turbulence Conference, September 4-6, 2023, Valencia, Spain

We presented a newly developed methodology to track Lagrangian fluctuations of physical and chemical quantities in the atmosphere. The measurements are carried out by using a freely floating cluster of mini, innovative radiosondes. The primary aim of this method is to obtain Lagrangian statistics of the turbulence fluctuations inside warm clouds, their boundaries and the surrounding sub-saturated environmental air. This is important information, difficult to find at the state of the art and very useful for modeling cloud formations which are still a primary source of uncertainty in the numerical simulation of climatic and meteorological information.

Turbulent dispersion analysis via distance-neighbor graphs inside a top cloud boundary in temporal decay

Year
2023
Document type
Proceeding
Authors
Shahbozbek Abdunabiev, Niccolo' Gallino, Antonella Abba', Daniela Tordella
Source

18th European Turbulence Conference

September 4-6, 2023, Valencia, Spain

https://etc18.webs.upv.es/wp-content/uploads/2023/08/Program_final_impresion.pdf

We expand on the original studies on atmospheric diffusion shown on a distance neighbour graph, Q, by Lewis F. Richardson (1926), a quantity that effectively defines a distribution of particles over a separation distance, ℓ. Because of its definition we expect Q to evolve according to an equation of type ∂Q/∂t = ∂/∂l (F(l)∂Q/∂l). Particular emphasis was put on the search for a correct form of the diffusion function F. Richardson originally proposed an F ∼ l^(4/3) law. His studies have then been revisited by many, among which Obukhov, leading to the so-called Richardson-Obukhov l^2 ∼ t^3 theory, which holds in the homogeneous, isotropic turbulence regime. Our analysis is carried out on direct numerical simulations (DNS) of a time-decaying turbulent shear-free layer which represents a small portion of a top warm cloud boundary, a multiphase simulation where air, water vapor and water drops have been included.

LoRa based remote expendable radiosonde network for environmental observations

Year
2023
Document type
Proceeding
Authors
Shahbozbek Abdunabiev, Eros Pasero, Daniela Tordella

The radiosonde cluster network was presented in the context of Metrology for Industry 4.0 & IoT 2023 conference on June 6-8 at Brescia, Italy.

The aim of the present work is to design and develop a remote radiosonde cluster network and receiver station based on LoRa radio communication protocol. The designed remote sensing unit, radiosonde, should be light (less then 20 gr) and expendable as much as possible. The radiosonde tracks variations of physical and chemical quantities in the surrounding environmental ambient. Primary target of this this new kind of radiosonde is to obtain Lagrangian statistics of turbulence fluctuations inside warm clouds, clear-air and cloud-clear-air mixing regions. However, the application of the sensor network is not limited and can be extended to other contexts, such as environmental monitoring over urban and industrial areas. The radiosonde is made of the radioprobe attached to a biodegradable balloon filled with a mixture of helium and air. The system is able to float inside and around clouds for a time span of the order of a few hours and measure fluctuations of air temperature, pressure, humidity position, velocity and acceleration along its own trajectory. In this manner, the system can provide a multipoint endoscopic view of the flow by following the air parcels in passive way.

preprint2.9 MB

Microphysical time scales, supersaturation fluctuations and droplet distance-neighbour statistical analysis at a warm Cloud Top Boundary

Year
2022
Document type
Proceeding
Authors
Ludovico Fossa, Shahbozbek Abdunabiev, Mina Golshan, Daniela Tordella
Source

75th Annual Meeting of the Division of Fluid Dynamics

Volume 67, Number 19

Sunday–Tuesday, November 20–22, 2022; Indiana Convention Center, Indianapolis, Indiana.

Session L33: Geophysical Fluid Dynamics: Clouds and Fog

Recent results have shown that there is an acceleration in the spread of the size distribution of droplet populations in the region bordering the cloud and undersaturated ambient. We have analyzed the supersaturation balance in this region, which is typically a highly intermittent shearless turbulent mixing layer, under a condition where there is no mean updraft. We have investigated the evolution of the cloud - clear air interface and of the droplets therein via direct numerical simulations. We have compared horizontal averages of the phase relaxation, evaporation, reaction and condensation times within the cloud-clear air interface for the size distributions of the initial monodisperse and polydisperse droplet populations.

We will also present results on turbulence dispersion in the cloud - clear air interface based on the distance neighbor graph statistics (Richardson, 1926) obtained by tracking water droplets in the Lagrangian framework.

 

Electronic design of innovative mini ultralight radioprobes aimed at tracking lagrangian turbulence fluctuations within warm clouds

Year
2022
Document type
Doctoral thesis
Authors
Miryam Elizabeth Paredes Quintanilla

Potential-enstrophy length scale for the turbulent/nonturbulent interface in stratified flow

Year
2022
Document type
Article
Authors
Marco Boetti, Maarten van Reeuwijk, and Alexander Liberzon
Phys. Rev. Fluids 6, 114803 – Published 15 November 2021

The paper published by Marco Boetti, Maarten van Reeuwijk, and Alexander Liberzon.

 

Aim> Turbulent/nonturbulent interfaces typically have a thickness of the order of the Kolmogorov scale. However, when we add a density or temperature stratification, we observe that the interface thickness scales differently. We analyze two different turbulent flows at moderate Reynolds numbers using direct numerical simulation and demonstrate that the results collapse on a single curve using a lengthscale based on the potential enstrophy.

 link:

 https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.6.114803

Microphysical time scales and local supersaturation balance at a warm Cloud Top Boundary, ERCOFTAC

Year
2022
Document type
Article
Authors
Shahbozbek Abdunabiev, Mina Golshan, Daniela Tordella

The work was presented during the "Turbulence and Interface, PC Henri Benard Workshop" on June 15-17, Lyon, France.

The present work discusses investigation of the evolution of the cloud - clear air interface and of the droplets therein via direct numerical simulations. We have compared horizontal averages of the phase relaxation, evaporation, reaction and condensation times within the cloud-clear air interface for the size distributions of the initial monodispersed and polydisperse droplets. For the monodisperse population,a clustering of the values of the reaction, phase and evaporation times, that is around 20-30 seconds, is observed in the central area of the mixing layer, just before the location where the maximum value of the supersaturation turbulent flux occurs.

MICROPHYSICAL TIME SCALES AT A WARM CLOUD TOP BOUNDARY

Year
2022
Document type
Proceeding
Authors
Ludovico Foss`a, Shahbozbek Abdunabiev, Mina Golshan, Daniela Tordella
Source

33rd Parallel CFD International Conference

May 24-26, 2022, Alba, Italy

We have analyzed the supersaturation balance in the region bordering the cloud and undersaturated ambient, which is typically a highly intermittent shearless turbulent mixing layer, under a condition where there is no mean updraft. We have compared horizontal averages of the phase relaxation, evaporation, reaction and condensation times within the cloud-clear air interface for the size distributions of the initial monodisperse and polydisperse droplets. For the monodisperse population, a clustering of the values of the reaction, phase and evaporation times, that is around 20-30 seconds, is observed in the central area of the mixing layer, just before the location where the maximum value of the supersaturation  turbulent flux occurs. This clustering of values is similar for the polydisperse population but also includes the condensation time.

Diffusion of turbulence following both stable and unstable step stratification perturbations

Year
2022
Document type
Article
Authors
Luca Gallana, Shahbozbek Abdunabiev, Mina Golshan, Daniela Tordell
Source

Politecnico di Torino

 

The recent paper has been published on Physics of Fluids with a following title:

"Diffusion of turbulence following both stable and unstable step stratification perturbations" 

   Physics of Fluids (2022); https://doi.org/10.1063/5.0090042

     Luca Gallana, Shahbozbek Abdunabiev, Mina Golshan,  Daniela Tordella

The evolution of a two-phase, air and unsaturated water vapor, time decaying, shearless, turbulent layer has been studied in the presence of both stable and unstable perturbations of the normal temperature lapse rate. The top interface between a warm vapor cloud and clear air in the absence of water droplets was considered as the reference dynamics. Direct, three dimensional, numerical simulations were performed within a 6m x 6m wide and 12m high domain, which was hypothesized to be located close to an interface between the warm cloud and clear air. The Taylor micro-scale Reynolds’ number was 250 inside the cloud portion. The squared Froude’s number varied over intervals of [0.4; 981.6] and [-4.0; -19.6]. A sufficiently intense stratification was observed to change the mixing dynamics. The formation of a sub layer inside the shearless layer was observed. The sub-layer, under a stable thermal stratification condition, behaved like a pit of kinetic energy. However, it was observed that kinetic energy transient growth took place under unstable conditions, which led to the formation of an energy peak just below the center of the shearless layer. The scaling law of the energy time variation inside the interface region was quantified: this is an algebraic law with an exponent that depends on the perturbation stratification intensity. The presence of an unstable stratification increased the differences in statistical behavior among the longitudinal velocity derivatives, compared with the unstratified case. Since the mixing process is suppressed in stable cases, small-scale anisotropy is also suppressed.