Cloud Cores Research Articles

Proposed Smart Monitoring System for the Detection of Bee Swarming

This paper presents a bee-condition-monitoring system incorporated with a deep-learning process to detect bee swarming. This system includes easy-to-use image acquisition and various end node approaches for either on-site or cloud-based mechanisms. This system also incorporates a new smart CNN engine called Swarm-engine for detecting bees and the issue of notifications in cases of bee swarming conditions to the apiarists. First, this paper presents the authors’ proposed implementation system architecture and end node versions that put it to the test. Then, several pre-trained networks of the authors’ proposed CNN Swarm-engine were also validated to detect bee-clustering events that may lead to swarming. Finally, their accuracy and performance towards detection were evaluated using both cloud cores and embedded ARM devices on parts of the system’s different end-node implementations.

A Two Stage Task Scheduler for Effective Load Optimization in Cloud – FoG Architectures

In recent times, computing technologies have moved over to a new dimension with the advent of cloud platforms which provide seamless rendering of required services to consumers either in static or dynamic state. In addition, the nature of data being handled in today’s scenario has also become sophisticated as mostly real time data acquisition systems equipped with High-Definition capture (HD) have become common. Lately, cloud systems have also become prone to computing overheads owing to huge volume of data being imparted on them especially in real time applications. To assist and simplify the computational complexity of cloud systems, FoG platforms are being integrated into cloud interfaces to streamline and provide computing at the edge nodes rather at the cloud core processors, thus accounting for reduction of load overhead on cloud core processors. This research paper proposes a Two Stage Load Optimizer (TSLO) implemented as a double stage optimizer with one being deployed at FoG level and the other at the Cloud level. The computational complexity analysis is extensively done and compared with existing benchmark methods and superior performance of the suggested method is observed and reported.

Imprint of planet formation in the deep interior of the Sun

In protoplanetary disks, the growth and inward drift of dust lead to the generation of a temporal “pebble wave” of increased metallicity. This phase must be followed by a phase in which the exhaustion of the pebbles in the disk and the formation of planets lead to the accretion of metal-poor gas. At the same time, disk winds may lead to the selective removal of hydrogen and helium from the disk. Hence, stars grow by accreting gas that has an evolving composition. In this work, we investigated how the formation of the Solar System may have affected the composition and structure of the Sun, and whether it plays any role in solving the so-called solar abundance problem, that is, the fact that standard models with up-to-date lower-metallicity abundances reproduce helioseismic constraints significantly more poorly than those with old higher-metallicity abundances. We simulated the evolution of the Sun from the protostellar phase to the present age and attempted to reproduce spectroscopic and helioseismic constraints. We performed chi-squared tests to optimize our input parameters, which we extended by adding secondary parameters. These additional parameters accounted for the variations in the composition of the accreted material and an increase in the opacities. We confirmed that, for realistic models, planet formation occurs when the solar convective zone is still massive; thus, the overall changes due to planet formation are too small to significantly improve the chi-square fits. We found that solar models with up-to-date abundances require an opacity increase of 12%–18% centered at T = 106.4 K to reproduce the available observational constraints. This is slightly higher than, but is qualitatively in good agreement with, recent measurements of higher iron opacities. These models result in better fits to the observations than those using old abundances; therefore, they are a promising solution to the solar abundance problem. Using these improved models, we found that planet formation processes leave a small imprint in the solar core, whose metallicity is enhanced by up to 5%. This result can be tested by accurately measuring the solar neutrino flux. In the improved models, the protosolar molecular cloud core is characterized by a primordial metallicity in the range Zproto = 0.0127–0.0157 and a helium mass fraction in the range Yproto = 0.268–0.274.

Online Adaptive Interference-Aware VNF Deployment and Migration for 5G Network Slice

Based on network function virtualization (NFV) and software defined network (SDN), <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">network slicing</i> is proposed as a new paradigm for building service-customized 5G network. In each network slice, service-required virtual network functions (VNFs) can be flexibly deployed in an on-demand manner, which will support a variety of 5G use cases. However, due to the real-time network variations and diverse performance requirements among different 5G scenarios, online adaptive VNF deployment and migration are needed to dynamically accommodate to service-specific requirements. In this paper, we first propose a time-slot based 5G network slice model, which jointly includes both edge cloud servers and core cloud servers. Since VNF consolidation may cause severe performance degradation, we adopt a demand-supply model to quantify the VNF interference. To achieve our objective—maximizing the total reward of accepted requests (i.e., the total throughput minus the weighted total VNF migration cost), we propose an Online Lazy-migration Adaptive Interference-aware Algorithm (OLAIA) for real-time VNF deployment and cost-efficient VNF migration in a 5G network slice, where an Adaptive Interference-aware Algorithm (AIA) is proposed as OLAIA’s core function for placing a given set of requests’ VNFs with maximized total throughput. Through trace-driven evaluations on two typical 5G network slices, we demonstrate that OLAIA can efficiently handle the real-time network variations and the VNF interference when deploying VNFs for real-time arriving requests. In particular, OLAIA improves the total reward by 22.18% in the autonomous driving scenario and by 51.10% in the 4K/8K HD video scenario, as compared with other state-of-the-art solutions.

Molecular cloud collapse to stellar densities: models on moving geodesic vs. unstructured tetrahedron vs. nested meshes

The results of a study of a collapsing cold molecular cloud with three computational models based on different mesh methods are presented. Collapse of a gas with a molecular cloud core density (≈ 10–18 g cm–3) to stellar densities (≈ 10–2 g cm–3) is considered. To simulate the collapse, the equation of state for an ideal gas and three mesh computational models are used. These are: a model based on multilevel nested meshes, a model based on moving geodesic meshes, and a model based on nonuniform tetrahedral meshes. The restrictions on the resolution in solving the Poisson equation and on the reproduction of the gravitational potential gradient on geodesic and tetrahedral meshes do not allow reproducing well the onset of collapse (in the case of moving geodesic meshes) or the maximum density (in the case of tetrahedral meshes). The results of computational experiments show that the process of collapse is reproduced well on multilevel nested meshes with sufficient spatial resolution.

FORCAST Imaging of Two Small Nearby Clusters: The Coronet and B 59

Abstract We present mid-infrared imaging of two young clusters, the Coronet in the CrA cloud core and B 59 in the Pipe Nebula, using the FORCAST camera on the Stratospheric Observatory for Infrared Astronomy. We also analyze Herschel Space Observatory 4 4 Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. PACS and SPIRE images of the associated clouds. The two clusters are at similar, and very close, distances. Star formation is ongoing in the Coronet, which hosts at least one Class 0 source and several pre-stellar cores, which may collapse and form stars. The B 59 cluster is older, although it still has a few Class I sources, and is less compact. The CrA cloud has a diameter of ∼0.16 pc, and we determine a dust temperature of 15.7 K and a star formation efficiency of ∼27%. The B 59 core is approximately twice as large, with a dust temperature of ∼11.4 K and a star formation efficiency of ∼14%. We infer that the gas densities are much higher in the Coronet, which has also formed intermediate-mass stars, while B 59 has only formed low-mass stars.

Environmental sensitivities of shallow-cumulus dilution – Part 2: Vertical wind profile

Abstract. This second part of a numerical study on shallow-cumulus dilution focuses on the sensitivity of cloud dilution to changes in the vertical wind profile. Insights are obtained through large-eddy simulations of maritime and continental cloud fields. In these simulations, the speed of the initially uniform geostrophic wind and the strength of geostrophic vertical wind shear in the cloud and subcloud layer are varied. Increases in the cloud-layer vertical wind shear (up to 9 ms-1km-1) lead to 40 %–50 % larger cloud-core dilution rates compared to their respective unsheared counterparts. When the background wind speed, on the other hand, is enhanced by up to 10 m s−1 and subcloud-layer vertical wind shear develops or is initially prescribed, the dilution rate decreases by up to 25 %. The sensitivities of the dilution rate are linked to the updraft strength and the properties of the entrained air. Increases in the wind speed or vertical wind shear result in lower vertical velocities across all sets of experiments with stronger reductions in the cloud-layer wind shear simulation (27 %–47 %). Weaker updrafts are exposed to mixing with the drier surrounding air for a longer time period, allowing more entrainment to occur (i.e., the “core-exposure effect”). However, reduced vertical velocities, in concert with increased cloud-layer turbulence, also assist in widening the humid shell surrounding the cloud cores, leading to entrainment of more humid air (i.e., the “core–shell dilution effect”). In the experiments with cloud-layer vertical wind shear, the core-exposure effect dominates and the cloud-core dilution increases with increasing shear. Conversely, when the wind speed is increased and subcloud-layer vertical wind shear develops or is imposed, the core–shell dilution effect dominates to induce a buffering effect. The sensitivities are generally stronger in the maritime simulations, where weaker sensible heat fluxes lead to narrower, more tilted, and, therefore, more suppressed cumuli when cloud-layer shear is imposed. Moreover, in the experiments with subcloud wind shear, the weaker baseline turbulence in the maritime case allows for a larger turbulence enhancement, resulting in a widening of the transition zones between the cores and their environment, leading to the entrainment of more humid air.

A new formation scenario of a counter-rotating circumstellar disk: Spiral-arm accretion from a circumbinary disk in a triple protostar system

Abstract We present the evolution of rotational directions of circumstellar disks in a triple protostar system simulated from a turbulent molecular cloud core with no magnetic field. We find a new formation pathway of a counter-rotating circumstellar disk in such triple systems. The tertiary protostar forms via the circumbinary disk fragmentation and the initial rotational directions of all three circumstellar disks are almost parallel to that of the orbital motion of the binary system. Their mutual gravito-hydrodynamical interaction for the subsequent ∼104 yr greatly disturbs the orbit of the tertiary, and the rotational directions of the tertiary disk and star are reversed due to the spiral-arm accretion of the circumbinary disk. The counter-rotation of the tertiary circumstellar disk continues to the end of the simulation (∼6.4 × 104 yr after its formation), implying that the counter-rotating disk is long-lived. This new formation pathway during the disk evolution in Class 0/I young stellar objects possibly explains the counter-rotating disks recently discovered by ALMA.

Remote patient monitoring and classifying using the internet of things platform combined with cloud computing

Many researchers have recently considered patients’ health and provided an optimal and appropriate solution. With the advent of technologies such as cloud computing, Internet of Things and 5G, information can be exchanged faster and more securely. The Internet of things (IoT) offers many opportunities in the field of e-health. This technology can improve health services and lead to various innovations in this regard. Using cloud computing and IoT in this process can significantly improve the monitoring of patients. Therefore, it is important to provide a useful method in the medical industry and computer science to monitor the status of patients using connected sensors. Thus, due to its optimal efficiency, speed, and accuracy of data processing and classification, the use of cloud computing to process the data collected from remote patient sensors and IoT platform has been suggested. In this paper, a prioritization system is used to prioritize sensitive information in IoT, and in cloud computing, LSTM deep neural network is applied to classify and monitor patients’ condition remotely, which can be considered as an important innovative aspect of this paper. Sensor data in the IoT platform is sent to the cloud with the help of the 5th generation Internet. The core of cloud computing uses the LSTM (long short-term memory) deep neural network algorithm. By simulating the proposed method and comparing the obtained results with other methods, it is observed that the accuracy of the proposed method is 97.13%, which has been improved by 10.41% in average over the other methods.

Transition of the initial mass function in the metal-poor environments

Abstract We study star cluster formation in a low-metallicity environment using three dimensional hydrodynamic simulations. Starting from a turbulent cloud core, we follow the formation and growth of protostellar systems with different metallicities ranging from 10−6 to 0.1 Z⊙. The cooling induced by dust grains promotes fragmentation at small scales and the formation of low-mass stars with M* ∼ 0.01–0.1 M⊙ While the number of low-mass stars increases with metallicity, when Z/Z⊙ ≳ 10−5. the stellar mass distribution is still top-heavy for Z/Z⊙ ≲ 10−2 compared to the Chabrier initial mass function (IMF). In these cases, star formation begins after the turbulent motion decays and a single massive cloud core monolithically collapses to form a central massive stellar system. The circumstellar disk preferentially feeds the mass to the central massive stars, making the mass distribution top-heavy. When Z/Z⊙ = 0.1, collisions of the turbulent flows promote the onset of the star formation and a highly filamentary structure develops owing to efficient fine-structure line cooling. In this case, the mass supply to the massive stars is limited by the local gas reservoir and the mass is shared among the stars, leading to a Chabrier-like IMF. We conclude that cooling at the scales of the turbulent motion promotes the development of the filamentary structure and works as an important factor leading to the present-day IMF.

Evolutionary view through the starless cores in Taurus

Context. The chemical and physical evolution of starless and pre-stellar cores are of paramount importance to understanding the process of star formation. The Taurus Molecular Cloud cores TMC 1-C and TMC 1-CP share similar initial conditions and provide an excellent opportunity to understand the evolution of the pre-stellar core phase. Aims. We investigated the evolutionary stage of starless cores based on observations towards the prototypical dark cores TMC 1-C and TMC 1-CP. Methods. We mapped the prototypical dark cores TMC 1-C and TMC 1-CP in the CS 3 → 2, C34S 3 → 2, 13CS 2 → 1, DCN 1 → 0, DCN 2 → 1, DNC 1 → 0, DNC 2 → 1, DN13C 1 → 0, DN13C 2 → 1, N2H+ 1 → 0, and N2D+ 1 → 0 transitions. We performed a multi-transitional study of CS and its isotopologs, DCN, and DNC lines to characterize the physical and chemical properties of these cores. We studied their chemistry using the state-of-the-art gas-grain chemical code NAUTILUS and pseudo time-dependent models to determine their evolutionary stage. Results. The central nH volume density, the N2H+ column density, and the abundances of deuterated species are higher in TMC 1-C than in TMC 1-CP, yielding a higher N2H+ deuterium fraction in TMC 1-C, thus indicating a later evolutionary stage for TMC 1-C. The chemical modeling with pseudo time-dependent models and their radiative transfer are in agreement with this statement, allowing us to estimate a collapse timescale of ~1 Myr for TMC 1-C. Models with a younger collapse scenario or a collapse slowed down by a magnetic support are found to more closely reproduce the observations towards TMC 1-CP. Conclusions. Observational diagnostics seem to indicate that TMC 1-C is in a later evolutionary stage than TMC 1-CP, with a chemical age ~1 Myr. TMC 1-C shows signs of being an evolved core at the onset of star formation, while TMC 1-CP appears to be in an earlier evolutionary stage due to a more recent formation or, alternatively, a collapse slowed down by a magnetic support.

Chemical Complexity of Phosphorous-bearing Species in Various Regions of the Interstellar Medium

Abstract Phosphorus-related species are not known to be as omnipresent in space as hydrogen, carbon, nitrogen, oxygen, and sulfur-bearing species. Astronomers spotted very few P-bearing molecules in the interstellar medium and circumstellar envelopes. Limited discovery of the P-bearing species imposes severe constraints in modeling the P-chemistry. In this paper, we carry out extensive chemical models to follow the fate of P-bearing species in diffuse clouds, photon-dominated or photodissociation regions (PDRs), and hot cores/corinos. We notice a curious correlation between the abundances of PO and PN and atomic nitrogen. Since N atoms are more abundant in diffuse clouds and PDRs than in the hot core/corino region, PO/PN reflects &lt;1 in diffuse clouds, ≪1 in PDRs, and &gt;1 in the late warm-up evolutionary stage of the hot core/corino regions. During the end of the post-warm-up stage, we obtain PO/PN &gt; 1 for hot core and &lt;1 for its low-mass analog. We employ a radiative transfer model to investigate the transitions of some of the P-bearing species in diffuse cloud and hot core regions and estimate the line profiles. Our study estimates the required integration time to observe these transitions with ground-based and space-based telescopes. We also carry out quantum chemical computation of the infrared features of PH3, along with various impurities. We notice that SO2 overlaps with the PH3 bending-scissoring modes around ∼1000–1100 cm−1. We also find that the presence of CO2 can strongly influence the intensity of the stretching modes around ∼2400 cm−1 of PH3.

Analysis of aerosol–cloud interactions and their implications for precipitation formation using aircraft observations over the United Arab Emirates

Abstract. Aerosol and cloud microphysical measurements were collected by a research aircraft during August 2019 over the United Arab Emirates (UAE). The majority of scientific flights targeted summertime convection along the eastern Al Hajar Mountains bordering Oman, while one flight sampled non-orographic clouds over the western UAE near the Saudi Arabian border. In this work, we study the evolution of growing cloud turrets from cloud base (9 ∘C) up to the capping inversion level (−12 ∘C) using coincident cloud particle imagery and particle size distributions from cloud cores under different forcing. Results demonstrate the active role of background dust and pollution as cloud condensation nuclei (CCN) with the onset of their deliquescence in the subcloud region. Subcloud aerosol sizes are shown to extend from submicron to 100 µm sizes, with higher concentrations of ultra-giant CCN (d&gt;10 µm) from local sources closer to the Saudi border, compared with the eastern orographic region where smaller CCN are observed. Despite the presence of ultra-giant CCN from dust and pollution in both regions, an active collision–coalescence (C–C) process is not observed within the limited depths of warm cloud (&lt;1000 m). The state-of-the-art observations presented in this paper can be used to initialize modeling case studies to examine the influence of aerosols on cloud and precipitation processes in the region and to better understand the impacts of hygroscopic cloud seeding on these clouds.

A Lagrangian Study of Interfaces at the Edges of Cumulus Clouds

AbstractInterfaces at the edge of an idealized, nonprecipitating, warm cloud are studied using direct numerical simulation (DNS) complemented with a Lagrangian particle tracking routine. Once a shell has formed, four zones can be distinguished: the cloud core, visible shell, invisible shell, and the environment. The union of the visible and invisible regions is the shell commonly referred to in literature. The boundary between the invisible shell and the environment is the turbulent–nonturbulent interface (TNTI), which is typically not considered in cloud studies. Three million particles were seeded homogeneously across the domain and properties were recorded along individual trajectories. The results demonstrate that the traditional cloud boundary (separating cloudy and noncloudy regions using thresholds applied on liquid condensate or updraft velocity) are some distance away from the TNTI. Furthermore, there is no dynamic difference between the traditional liquid-condensate boundary and the region extending to the TNTI. However, particles crossing the TNTI exhibit a sharp jump in enstrophy and a smooth increase in buoyancy. The traditional cloud boundary coincides with the location of minimum buoyancy in the shell. The shell premixes the entraining and detraining air and analysis reveals a highly skewed picture of entrainment and detrainment at the traditional cloud boundary. A preferential entrainment of particles with velocity and specific humidity higher than the mean values in the shell is observed. Large-eddy simulation of a more realistic setup detects an interface with similar properties using the same thresholds as in the DNS, indicating that the DNS results extrapolate beyond their idealized conditions.

Intelligent Identification of Convective Cloud Cores and Surrounding Stratiform Clouds

Convective cloud cores and surrounding stratiform clouds in the same precipitation process were identified by Lagrange tracking method to reveal differences of cloud microphysical processes in areas with different development intensities in the same precipitation system. Firstly, a scale operator was introduced for post-processing of the tracking method to determine the height most appropriate for tracking in 3D data. Secondly, different identification thresholds were set according to the radar reflectivity factor. Regions with the factor greater than 40dBZ were defined as convective cloud cores, and those with the factor more than 20dBZ and less than 40dBZ as stratiform clouds around cores. Finally, analysis was conducted on their differences in the motion trajectory, duration and development range in a weather process. The results showed that changes in the duration and the areas of convective cloud cores and stratiform clouds reflected the intensity of microphysical processes in different regions; the microphysical process of the regions with short-duration but large-area convective cloud cores were more intense, while that of the regions with long-life and small-area cores developed more smoothly.

Load balancing in virtualized environments using virtual machine migration: A comprehensive survey

Virtualization is a core and requisite technology in Cloud Computing that provisions scalable virtual resources for execution of varied applications. It enables the cloud datacenter resources to be multiplexed within numerous virtual computing environments recognized as virtual machines. These virtual machines consolidates varied applications with diversified resource requirements. It prompts to increase in load imbalance level leading to reduced performance and SLA violations. In order to achieve load balancing across virtual machines varied approaches are presented in literature and virtual machine migration based load balancing is a popular move in this direction. In this work, recent literature on different migration based load balancing schemes are reviewed. The objective of the work is highlight the features, advantages and shortcomings of the considered literature. Alongside that, the effort is conferred to provide an analytical view over different perspectives which will motivate the research in this area.

Convective and Turbulent Motions in Nonprecipitating Cu. Part I: Method of Separation of Convective and Turbulent Motions

AbstractAtmospheric motions in clouds and cloud surroundings have a wide range of scales, from several kilometers to centimeters. These motions have different impacts on cloud dynamics and microphysics. Larger-scale motions (hereafter referred to as convective motions) are responsible for mass transport over distances comparable with cloud scale, while motions of smaller scales (hereafter referred to as turbulent motions) are stochastic and responsible for mixing and cloud dilution. This distinction substantially simplifies the analysis of dynamic and microphysical processes in clouds. The present research is Part I of the study aimed at describing the method for separating the motion scale into a convective component and a turbulent component. An idealized flow is constructed, which is a sum of an initially prescribed field of the convective velocity with updrafts in the cloud core and downdrafts outside the core, and a stochastic turbulent velocity field obeying the turbulent properties, including the −5/3 law and the 2/3 structure function law. A wavelet method is developed allowing separation of the velocity field into the convective and turbulent components, with parameter values being in a good agreement with those prescribed initially. The efficiency of the method is demonstrated by an example of a vertical velocity field of a cumulus cloud simulated using the System for Atmospheric Modeling (SAM) with bin microphysics and resolution of 10 m. It is shown that vertical velocity in clouds indeed can be represented as a sum of convective velocity (forming zone of cloud updrafts and subsiding shell) and a stochastic velocity obeying laws of homogeneous and isotropic turbulence.

Water and methanol ice in L 1544

Context. Methanol and complex organic molecules have been found in cold starless cores, where a standard warm-up scenario would not work because of the absence of heat sources. A recent chemical model attributed the presence of methanol and large organics to the efficient chemical desorption and a class of neutral-neutral reactions that proceed fast at low temperatures in the gas phase. Aims. The model calls for a high abundance of methanol ice at the edge of the CO freeze-out zone in cold cloud cores. Methods. We performed medium-resolution spectroscopy toward three field stars behind the starless core L 1544 at 3 μm to constrain the methanol ice abundance and compare it with the model predictions. Results. One of the field stars shows a methanol ice abundance of 11% with respect to water ice. This is higher than the typical methanol abundance previously found in cold cloud cores (4%), but is 4.5 times lower than predicted. The reason for the disagreement between the observations and the model calculations is not yet understood.

First survey of HCNH+in high-mass star-forming cloud cores

Context.Most stars in the Galaxy, including the Sun, were born in high-mass star-forming regions. It is hence important to study the chemical processes in these regions to better understand the chemical heritage of the Solar System and most of the stellar systems in the Galaxy.Aims.The molecular ion HCNH+is thought to be a crucial species in ion-neutral astrochemical reactions, but so far it has been detected only in a handful of star-forming regions, and hence its chemistry is poorly known.Methods.We observed with the IRAM 30 m Telescope 26 high-mass star-forming cores in different evolutionary stages in theJ= 3−2 rotational transition of HCNH+.Results.We report the detection of HCNH+in 16 out of 26 targets. This represents the largest sample of sources detected in this molecular ion to date. The fractional abundances of HCNH+with respect to H2, [HCNH+], are in the range 0.9−14 × 10−11, and the highest values are found towards cold starless cores, for which [HCNH+] is of the order of 10−10. The abundance ratios [HCNH+]/[HCN] and [HCNH+]/[HCO+] are both ≤0.01 for all objects except for four starless cores, which are well above this threshold. These sources have the lowest gas temperatures and average H2volume density values in the sample. Based on this observational difference, we ran two chemical models, ‘cold’ and ‘warm’, which attempt to match the average physical properties of the cold(er) starless cores and the warm(er) targets as closely as possible. The reactions occurring in the latter case are investigated in this work for the first time. Our predictions indicate that in the warm model HCNH+is mainly produced by reactions with HCN and HCO+, while in the cold model the main progenitor species of HCNH+are HCN+and HNC+.Conclusions.The observational results indicate, and the model predictions confirm, that the chemistry of HCNH+is different in cold–early and warm–evolved cores, and the abundance ratios [HCNH+]/[HCN] and [HCNH+]/[HCO+] can be useful astrochemical tools to discriminate between different evolutionary phases in the process of star formation.

Analysis on Evolution Characteristics of Hydrometeors in South China Based on Lagrange Tracking Method

To reveal the microphysical process of clouds inside a rain cluster and identify the causes of changes in water resources in the air in South China, rain cluster areas with the radar reflectivity factor higher than 40dBZ in a heavy precipitation process in South China were defined as convective cloud cores, and areas with the factor greater than 20dBZ and less than 40dBZ as stratiform clouds around cores with Lagrange tracking method based on S-band dual-polarization radar data. An analysis was conducted on the evolution law of the types of hydrometeor particles and variation characteristics of the raindrop size spectrum in the two areas as well as their differences. The results showed that convective cloud cores and surrounding stratiform clouds were composed of large and sparse raindrops at the early stage of development; the particle crushing process mainly occurred inside stratiform clouds at the mature stage, and the collision-coalescence process mainly occurred at the attenuation stage. Stratiform clouds showed a process of increase in the density of graupel particles at the stage of precipitation enhancement, but the density of graupel particles in convective cores did not change significantly; high- and low-density graupel particles in convective cores had a higher frequency of occurrence than those in stratiform clouds.