Jet Core Research Articles

Analysis of Thermal Runaway in Pouch-Type Lithium-Ion Batteries Using Particle Image Velocimetry

Despite widespread recognition of the serious risk of battery thermal runaway (BTR) in lithium-ion batteries, the process and associated external ignition mechanism remain poorly understood. In this study, BTR was measured using thermodynamics and visualization techniques in 10 lithium-ion batteries under thermal abuse conditions. The venting speed was measured by particle image velocimetry and boundary detection. The external ignition mechanism was characterized in terms of flame area. The average BTR onset temperature across the 10 test batteries was 215.6°C. The average maximum temperature was 831.1°C, and the variation between experiments was high compared with the BTR onset temperature due to swelling, repairing, and venting. BTR occurred in four stages (ejection of vent gas with flame, extinction of flame, random and simultaneous ignition, and flame propagation and flame jet formation). The initial average venting speed was approximately 123.8 m/s. The structural and venting speeds of vent gas were similar after a stable flame jet formed. The speed of the core of the gas jet peaked at 20 to 40 m/s. The venting speed decreased as the distance from the jet core increased.

Noise and Jet Momentum of Synthetic Jet Actuators with Different Orifice Configurations

Sound pressure levels and flow characteristics of a synthetic jet actuator (SJA) are investigated experimentally using the following orifice configurations: a) a slender rectangular slot orifice and b) an array of circular orifices with two different orifice diameters. All configurations have similar total orifice neck area, orifice height, and cavity volume, resulting in a similar Helmholtz frequency. Experiments are conducted for orifices mounted on a flat plate under a quiescent condition. The mean jet velocity exhibits resonant peaks at several excitation frequencies, which also gave rise to the sound pressure levels. The resonant frequencies and peak jet velocities were found to depend on the excitation amplitude and orifice configuration. Investigation of the jet momentum penetration into the quiescent air above the different orifice configurations shows that the momentum issuing from the rectangular slot decays much quicker than that of the circular orifices, irrespective of whether the SJA is excited at resonance or not. The most favorable performance (i.e., the highest momentum in the jet core) was obtained with the array of circular orifices having a smaller orifice diameter, even at off-resonance excitations. The work herein shows the possibility of reducing the SJA noise by 8–10 dB by operating the SJA at a frequency away from the Helmholtz frequency while still achieving comparable levels of jet momentum penetration into the crossflow.

An objective procedure for rainy season onset and withdrawal dates over the Mexico Valley Basin

This work aims to define a procedure to declare rainy season onset and withdrawal dates for the Mexico Valley Basin, located in central Mexico. The onset/withdrawal is obtained using only precipitation for the study period 1981–2020. The onset is defined as the first day, between May 1st and July 15th, of the first 20 consecutive days having a 20-day average precipitation over the Basin of at least 2.5 mm/day. The withdrawal is defined as the last day, between September 1st and November 15th, of the last 20 consecutive days having a 20-day average precipitation of at least 1.7 mm/day. The mean onset is June 6th, with a standard deviation of 14.3 days; the mean withdrawal date is October 15th, with a standard deviation of 16.1 days; and the average length of the rainy season is 131 days, with a standard deviation of 22.7 days. These criteria maximize the precipitation change slope during onset/withdrawal. We categorized pre- and post-onset/withdrawal periods to investigate mean circulation characteristic changes. Besides a stark increase (decrease) in rainfall over the Basin during onset (withdrawal), we found that vertically integrated moisture transport over the Caribbean Low-Level Jet core region increases (decreases). The onset/withdrawal dates derived show interannual trends, while a late (early) withdrawal is associated with a positive (negative) ENSO Index, and a strong (weak) Caribbean Low Level Jet (CLLJ) is associated with a late (early) onset.

Illuminating evaporating protostellar outflows: ERIS/SPIFFIER reveals the dissociation and ionization of HH 900

ABSTRACT Protostellar jets and outflows are signposts of active star formation. In H ii regions, molecular tracers like CO only reveal embedded portions of the outflow. Outside the natal cloud, outflows are dissociated, ionized, and eventually completely ablated, leaving behind only the high-density jet core. Before this process is complete, there should be a phase where the outflow is partially molecular and partially ionized. In this paper, we capture the HH 900 outflow while this process is in action. New observations from the Enhanced Resolution Imager and Spectrograph/SPIFFIER near-infrared (IR) integral field unit spectrograph using the K-middle filter (λ = 2.06–2.34 μm) reveal H2 emission from the dissociating outflow and Br-γ tracing its ionized skin. Both lines trace the wide-angle outflow morphology but H2 only extends ∼5000 au into the H ii region while Br-γ extends the full length of the outflow (∼12 650 au), indicating rapid dissociation of the molecules. H2 has higher velocities further from the driving source, consistent with a jet-driven outflow. Diagnostic line ratios indicate that photoexcitation, not just shocks, contributes to the excitation in the outflow. We argue that HH 900 is the first clear example of an evaporating molecular outflow and predict that a large column of neutral material that may be detectable with Atacama Large Millimeter Array accompanies the dissociating molecules. Results from this study will help guide the interpretation of near-IR images of externally irradiated jets and outflows such as those obtained with the JWST in high-mass star-forming regions where these conditions may be common.

Effect of tab shape, length, and placement on the over-expanded free jet at Mach 2.0

Abstract Experiments have been carried out to investigate the over expanded free jet at Mach number 2.0 without and with tabs of different cross-sectional shapes, tab length penetration into the jet core defined as blockage ratio, and symmetrical and asymmetrical placement of tabs at the jet exit. The cross-sectional shapes such as triangular, square, and circular have been studied with the penetration depth of 3 %, 7 %, and 11 % blockage. The Pitot tube and Schlieren flow visualization were carried out in experiments. The basic features of the jet with Mach disk, shock cell, and its distortion with the adoption of tabs at various nozzle pressure ratios indicate a definite influence that helps in the reduction of the core jet length. This characteristic is also influenced by changes in tab cross-section and length of penetration. Since the basic jet has three-dimensional structures, the asymmetric placement of tabs is beneficial compared to the symmetric orientation of tabs. The jet width increases with adoption of these tabs and different shapes. Whereas, a maximum core jet length reduction of the order of 60 % could be achieved using the present techniques.

Effect of tab shape, length, and placement on the over-expanded free jet at Mach 2.0

Abstract Experiments have been carried out to investigate the over expanded free jet at Mach number 2.0 without and with tabs of different cross-sectional shapes, tab length penetration into the jet core defined as blockage ratio, and symmetrical and asymmetrical placement of tabs at the jet exit. The cross-sectional shapes such as triangular, square, and circular have been studied with the penetration depth of 3 %, 7 %, and 11 % blockage. The Pitot tube and Schlieren flow visualization were carried out in experiments. The basic features of the jet with Mach disk, shock cell, and its distortion with the adoption of tabs at various nozzle pressure ratios indicate a definite influence that helps in the reduction of the core jet length. This characteristic is also influenced by changes in tab cross-section and length of penetration. Since the basic jet has three-dimensional structures, the asymmetric placement of tabs is beneficial compared to the symmetric orientation of tabs. The jet width increases with adoption of these tabs and different shapes. Whereas, a maximum core jet length reduction of the order of 60 % could be achieved using the present techniques.

Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures

Abstract. It has been demonstrated that decadal variations in the North Atlantic Oscillation (NAO) can be predicted by current forecast models. While Atlantic Multidecadal Variability (AMV) in sea surface temperatures (SSTs) has been hypothesised as the source of this skill, the validity of this hypothesis and the pathways involved remain unclear. We show, using reanalysis and data from two forecast models, that the decadal predictability of the NAO can be entirely accounted for by the predictability of decadal variations in the speed of the North Atlantic eddy-driven jet, with no predictability of decadal variations in the jet latitude. The sub-polar North Atlantic (SPNA) is identified as the only obvious common source of an SST-based signal across the models and reanalysis, and the predictability of the jet speed is shown to be consistent with a forcing from the SPNA visible already within a single season. The pathway is argued to be tropospheric in nature, with the SPNA-associated heating extending up to the mid-troposphere, which alters the meridional temperature gradient around the climatological jet core. The relative roles of anthropogenic aerosol emissions and the Atlantic Meridional Overturning Circulation (AMOC) at generating predictable SPNA variability are also discussed. The analysis is extensively supported by the novel use of a set of seasonal hindcasts spanning the 20th century and forced with prescribed SSTs.

Flow and acoustic fields investigation of noise reduction by micro vortex generators in supersonic nozzles

The role of micro-vortex generators (MVGs) in supersonic jet noise reduction is investigated. Studies are performed to understand the noise reduction mechanisms of these devices. MVGs are implemented on a scale model representative of GE-F404 nozzles. Configurations consisting of single and dual arrays of MVGs were tested for pressure ratios relevant to takeoff operating conditions. A combination of laboratory measurements and large-eddy simulations are used. Particle image velocimetry reveals that MVGs placed inside the nozzle form oblique shocks that interact with the jet plume's shock cell structure and greatly modify the shock-cell structure issued from the nozzle throat. This modification can weaken the jet plume shock-cell structure and even reduce the jet core velocities. Convective velocities estimated from the high-speed Schlieren imaging showed a significant reduction in magnitude caused by MVGs. When compared to the baseline design, the MVG nozzles showed noise reduction up to 10 dB in the upstream direction and near 5 dB in the peak downstream radiation angle at cold jet conditions. Near-field acoustic measurements showed a significant reduction of low-frequency turbulent mixing noise. Scaling analysis showed that MVGs are capable of delivering the same noise reduction performance across different model scales.

Numerical simulation and experimental research on oscillation performance of disc-type jet oscillator

Based on active flow control technology, the two wall jets attached to a standard cylindrical surface due to the Coanda effect will output a detached jet when they collide. The direction of the output jets produced by this collision is very sensitive to small changes in the two wall jets. Therefore, a new type of curved-wall supersonic compressible disc-type jet oscillator is proposed by using the oscillating feedback jet as the source of wall separation. Through monitoring the internal flow field, the jet core’s pressure attenuation, the jet’s amplitude, and the wall pressure are analyzed. The results show that the disc-type jet oscillator model with a double-bend inlet has the best performance. After adding a multi-pipe outlet structure to the model, the oscillators with various disc diameters were simulated at different inlet pressures and air inlet frequencies to the wall-off control port. The oscillation performance of the disc jet oscillator is better when the diameter of the disc is 32 mm and 20 mm, and the included angle between the wall-off control port and the horizontal direction is 45°. Two kinds of oscillators of the same diameter as the model are experimentally studied, and the results prove the feasibility of the disc-type jet oscillator.

Gangue Source Reduction Technology and Process Optimization Based on Underground Coal Gangue Photoelectric Separation

The precise identification of damp, sticky coal gangue; efficient jet nozzle separation; and process layout in a narrow, restricted space are essential technologies for gangue source reduction based on underground gangue photoelectric separation, which is critical for the long-term growth of coal mines. In this paper, the X-ray absorption fine structure (XAFS) method was used to identify the X-ray absorption law of different atoms in coal-based minerals and explore the differences in the microscopic crystal properties of coal gangue; the numerical simulation calculation of four commonly used nozzles—namely, flat, convergent, flat–convergent, and streamline—was carried out using Fluent software for coal gangue jet separation to optimize the nozzle morphology and parameters. The technical characteristics of the underground layout of the photoelectric separation system for coal gangue were expounded, and the technological layout of the separation system was explored. The results showed that the absorption coefficients μ(E) of Al and Si atoms in minerals to X-rays are significantly different, and the XAFS method has the ability to identify coal, gangue, and other minerals. The streamlined nozzle has a long jet core area, slow decay of jet velocity, low gas consumption per unit time, and better performance than the other three types of nozzles. Based on the development and mining system of the Renjiazhuang Coal Mine, three kinds of photoelectric separation system layout schemes of coal gangue were designed, namely centralized layout, distributed layout, and mobile layout. The advantages and disadvantages of each scheme were compared, which enriched the technical means of gangue source reduction.

Interannual impact of the Victoria mode on the winter-spring surface air temperature over Eurasia and North America

Variations of the Victoria mode (VM) have received considerable attention due to their profound impacts on the climate systems in the pan-North Pacific. However, works about its impact on surface air temperature (SAT) variability over Eurasia and North America, which may be responsible for extreme weather and climate events, are limited. Here we show a significant positive and negative relationship between the VM and the winter-spring SAT anomalies over mid-to-high-latitude east-central Eurasia (MEE) and eastern North America (ENA), respectively. A local energy budget analysis shows that the contribution of the surface heat fluxes associated with the VM to the SAT anomalies is confined mainly to MEE and may not explain the formation of SAT anomalies over ENA. Furthermore, VM-induced anomalous atmospheric circulations play a crucial role in the formation of notable SAT anomalies. The positive (negative) VM is linked to negative (positive) precipitation and upper-tropospheric wind convergence (divergence) anomalies over the western North Pacific, which contribute to positive (negative) Rossby wave source (RWS) anomalies near the East Asian westerly jet core. These RWS anomalies act as disturbances that propagate eastward, exciting a wave train-like pattern. The high-level positive and negative geopotential height anomalies of the Rossby wave dominate MEE and ENA, respectively, leading to the variation in SAT anomalies. These results could advance our understanding of the relationship between the VM and SAT over the Northern Hemisphere and inspire us to pay more attention to the VM climate impacts.

Numerical Simulation of Plasma Igniter Efflux Characteristics Based on Multi-Physical Field Coupling

To explore the chamber plasma jet ignition effect, the establishment of pre-chamber plasma jet ignition based on a 3D model using the method of numerical simulation was carried out on the working process of the plasma ignition numerical calculation. The analysis of firearms in the combustion chamber ignition characteristics provided a reference for the ignition performance boost. The results show that the jet velocity at the igniter outlet can reach 78 m/s and the jet temperature can reach 2300 K, which makes the hot jet spread far enough in the reflux area and ensures that the jet can achieve the effect of heating and igniting in a larger area. The mixture in the air reacts with the kerosene position along the border, ignition in the igniter fine channel before export, igniter speeding up the export position of flow velocity, the jet core region of the temperature of 2400 K, the igniter export position of kerosene component concentration was 45%, the concentration of O2 was 20%, the H2O concentration was 15%, and the CO2 concentration was 7%. The ratio of air to kerosene should be such that the two flow at similar speeds in the mixing area.

Numerical simulations of seawater spraying on launch platform during CZ-8X offshore launching

In this paper, the cooling effect of seawater spraying on the offshore launching platform used by the CZ-8X rocket at different takeoff heights is studied. The rocket plume model using the realizable k- ε turbulence model is established, which is based on the three-dimensional Navier-Stokes equations. The injected seawater for cooling the deck surface is described by the Eulerian dispersed phase (EDP) model. The numerical results are compared with the experimental data in the literature to verify the validity and accuracy of the numerical model. The coupled flow field of the CZ-8X rocket plume and seawater at different takeoff heights and different spray velocities are simulated. The results show that the thermal environment on the deck surface of the platform is the worst when the takeoff height reaches 30 m. The seawater spraying velocity shall be moderate before the takeoff height reaches 30 m. A low spraying velocity will lead to poor cooling effect on deck surface, and a high spraying velocity could lead to increased diffusion of plume flow in non-spraying direction. After the takeoff height rises to 40 m, a low water spraying velocity makes the injection position of seawater far away from the jet core area, and the seawater evaporation rate is low, which is conducive to the accumulation of seawater layer on the deck surface. The cooling effect of thermal barrier layer is very obvious. The research shows that when the rocket is launched at sea, the launch platform can be cooled by pumping and spraying seawater, and the water spraying rate can be adjusted appropriately according to the takeoff height to achieve the best cooling effect.

Probing the Heart of Active Narrow-line Seyfert 1 Galaxies with VERA Wideband Polarimetry

We explored the parsec-scale nuclear regions of a sample of radio-loud narrow-line Seyfert 1 galaxies (NLSy1s) using the VLBI Exploration of Radio Astrometry wideband (at a recording rate of 16 Gbps) polarimetry at 22 and 43 GHz. Our targets include 1H 0323+342, SBS 0846+513, PMN J0948+0022, 1219+044, PKS 1502+036, and TXS 2116-077, which are all known to exhibit γ-ray emission indicative of possessing highly beamed jets similar to blazars. For the first time, we unambiguously detected Faraday rotation toward the parsec-scale radio core of NLSy1s, with a median observed core rotation measure (RM) of 2.7 × 103 rad m−2 (or 6.3 × 103 rad m−2 for redshift-corrected). This level of RM magnitude is significantly larger than those seen in the core of BL Lacertae objects (BLOs; a dominant subclass of blazars), suggesting that the nuclear environment of NLSy1s is more gas-rich than that in BLOs. Interestingly, the observed parsec-scale polarimetric properties of NLSy1s (low core fractional polarization, large core RM and jet–EVPA misalignment) are rather similar to those of flat-spectrum radio quasars (FSRQs). Our results are in accordance with the scenario that NLSy1s are in an early stage of active galactic nucleus evolution with their central black hole masses being smaller than those of more evolved FSRQs.

Characteristics and dynamics of electrolyzed bubbles in magnetohydrodynamic bubbly jet

BackgroundThe magnetohydrodynamics (MHD) are highly relevant to practical applications, including marine propulsion and hydrogen production etc. For better implementation to applications, typical characteristics of the MHD bubbly jet, such as the size distribution and motion of oxygen and hydrogen bubbles, need to be well realized. MethodsThe MHD bubbly jet generated by high current density associated with strong permanent magnet is experimentally investigated. Two fields of view are taken to analyze the details of micro-sized bubbles and the whole pattern of bubbly jet. To couple the magnetoelectric effects and bubble dynamics, the Reynolds number based on the Lorentz force ReL is applied in the parametric analysis. FindingsDependence of the mean size of bubble on the current density is generally verified. Two regimes regarding the bubble sizes are distinguished. The proposed mechanisms of these two regimes are supported by the pattern of bubbly jet. For ReL≤2000, size of bubble monotonically increases with current density, so that referred to as the electrochemistry regime. Nevertheless, the size of bubble remains nearly unchanged for ReL>2000, referred to as the flow regime in which the turbulent breakup of the bubbly jet core starts to evolve.

Radio sources segmentation and classification with deep learning

Modern large radio continuum surveys have high sensitivity and resolution, and can resolve previously undetected extended and diffuse emissions, which brings great challenges for the detection and morphological classification of extended sources. We present HeTu-v2, a deep learning-based source detector that uses the combined networks of Mask Region-based Convolutional Neural Networks (Mask R-CNN) and a Transformer block to achieve high-quality radio sources segmentation and classification. The sources are classified into 5 categories: Compact or point-like sources (CS), Fanaroff–Riley Type I (FRI), Fanaroff–Riley Type II (FRII), Head–Tail (HT), and Core-Jet (CJ) sources. HeTu-v2 has been trained and validated with the data from the Faint Images of the Radio Sky at Twenty-one centimeters (FIRST). We found that HeTu-v2 has a high accuracy with a mean average precision (AP@50:5:95) of 77.8%, which is 15.6 points and 11.3 points higher than that of HeTu-v1 and the original Mask R-CNN respectively. We produced a FIRST morphological catalog (FIRST-HeTu) using HeTu-v2, which contains 835,435 sources and achieves 98.6% of completeness and up to 98.5% of accuracy compared to the latest 2014 data release of the FIRST survey. HeTu-v2 could also be employed for other astronomical tasks like building sky models, associating radio components, and classifying radio galaxies.

Joint analysis of gravitational-wave and electromagnetic data of mergers: breaking an afterglow model degeneracy in GW170817 and in future events

ABSTRACT On 2017 August 17, Advanced LIGO and Virgo observed GW170817, the first gravitational-wave (GW) signal from a binary neutron star merger. It was followed by a short-duration gamma-ray burst, GRB 170817A, and by a non-thermal afterglow emission. In this work, a combined simultaneous fit of the electromagnetic (EM, specifically, afterglow) and GW domains is implemented, both using the posterior distribution of a GW standalone analysis as prior distribution to separately process the EM data, and fitting the EM and GW domains simultaneously. These approaches coincide mathematically, as long as the actual posterior of the GW analysis, and not an approximation, is used as prior for the EM analysis. We treat the viewing angle, θv, as shared parameter across the two domains. In the afterglow modelling with a Gaussian structured jet this parameter and the jet core angle, θc, are correlated, leading to high uncertainties on their values. The joint EM + GW analysis relaxes this degeneracy, reducing the uncertainty compared to an EM-only fit. We also apply our methodology to hypothetical GW170817-like events occurring in the next GW observing run at ∼140 and 70 Mpc. At 70 Mpc the existing EM degeneracy is broken, thanks to the inclusion of the GW domain in the analysis. At 140 Mpc, the EM-only fit cannot constrain θv nor θc because of the lack of detections in the afterglow rising phase. Folding the GW data into the analysis leads to tighter constraints on θv, still leaving θc unconstrained, requiring instruments with higher sensitivities, such as Athena.

Numerical investigation about the unsteady behavior of a free submerged cavitation jet using the SBES approach

Submerged cavitation jet has emerged as an efficient method for the removal of ship fouling. Due to the complicated revolution of cavitation cloud, it has attracted great research interest. Ascertaining the internal flow dynamics of cavitating jets is always a challenge. Thus, this paper investigates the unsteady behavior of a free submerged cavitating jet numerically in three dimensions. The turbulent cavitation flow is simulated utilizing the Stress-Blended Eddy Simulation (SBES) turbulent model combined with the Schnerr-Sauer cavitation model. The results are compared with the data from a famous experiment, and they exhibit good agreement in both time-averaged and unsteady characteristics. The cavitation life stages, i.e., the cavitation growth, shedding, contraction, and collapse are explored. In results, cavitation cloud forms around the jet core. Cavitation cloud shedding involves complex factors, including shear layer instability, complex pressure gradients, and re-entrant motion, and it may also be related to the potential core and jet core instability. Additionally, cavitation cloud development is closely related to the jet core and exhibits synchronous behavior. After the cavitation cloud collapse, a local high pressure is observed and then cavity rebound is generated, where the collapse can be either mild or intensive.

Analytic model for off-axis GRB afterglow images – geometry measurement and implications for measuring H0

ABSTRACT We present an analytic model for measuring the jet core angle (θc) and viewing angle (θobs) of off-axis gamma-ray bursts independently of the jet angular structure outside of the core. We model the images of off-axis jets, and using this model, we show that θobs and θc can be measured using any two of the three following observables: the afterglow light curve, the flux-centroid motion, and the image width. The model is calibrated using 2D relativistic hydrodynamic simulations with a broad range of jet angular structures. We study the systematic errors due to the uncertainty in the jet structure and find that when using the light curve and centroid motion to determine θobs and θc, our formulae can be accurate to a level of 5–10 per cent and 30 per cent, respectively. In light of the Hubble tension, the systematic error in cos θobs in GRBs originating in a binary compact object merger is of special interest. We find that the systematic uncertainty on the measurement of cos θobs due to the unknown jet structure is smaller than 1.5 per cent for well-observed events. A similar error is expected if the microphysical parameters evolve at a level that is not easily detected by the light curve. Our result implies that this type of systematic uncertainty will not prevent measurement of H0 to a level of 2 per cent with a sample of well-observed GW events with resolved afterglow image motion. Applying our model to the light curve and centroid motion observations of GW170817, we find $\theta _{obs}=19.2\pm 2~\deg$ (1σ) and $\theta _c=1.5-4~\deg$.

Synoptic-Scale Effects of Atmospheric Heat Source over Key Areas of the Tibetan Plateau on Its Downstream Rainfall in Summer

Abstract This study demonstrates the synoptic-scale relationship between the atmospheric heat source over the Tibetan Plateau (TP) (TP<Q1>) and summer rainfall in eastern China. The results show that the summer TP<Q1> has three key areas [eastern, western, and northeastern TP (TPE, TPW, TPNE, respectively)] and 3–8-day dominant oscillation periods on the synoptic time scale for each subregion. Analogously, on the synoptic scale, the downstream rainfall of the TP in China has six sensitive regions (zone I to zone VI), each with 3–8-day dominant periods. The TPE<Q1>, TPW<Q1>, and TPNE<Q1> lead rainfall by 4 days with a southeastward propagation pathway, by 5 days with both southeastward and northeastward propagation routes, and by 4 days with an eastward route, respectively. Mechanistically, when TP<Q1> lies in the positive-to-negative transition phase, the rainfall moves off the TP and reaches the maximum in its most inactive phase; the jet cores embedded in the subtropical westerly jet band and the trough from the region of the TP<Q1> lead the eastward movement of the rainfall by the propagation of the divergence center and generalized moist potential vorticity. Besides, the southwest vortex and northwest vortex generated at the southeastern and northeastern flank of the TP are the main cause for the southeastward and northeastward or eastward movement of the precipitation. Further internal atmospheric dynamic structures indicate that both the horizontal moisture advection and generalized moist potential vorticity advection act on the entire propagation processes of the synoptic-scale signals for each TP<Q1> key area. In conclusion, the study has obvious theoretical significance and application value for the development of plateau synoptics.