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Spot jamming poses a significant threat to radar detection due to its ability to rapidly intercept radar signals and emit high‐power interference. A novel Cognitive Multi‐Carrier Radar (CMCR) is proposed, which utilises a detection waveform comprising multiple narrow bands to reduce the disruption from the spot jammer. Additionally, it can analyse the target's Radar Cross‐Section (RCS) characteristics and proactively select frequencies with high RCS for detection, thereby enhancing target detection capability. The online frequency allocation problem of CMCR is a Multi‐Armed Bandit (MAB) problem with a combinatorial action space. To tackle the challenge from the huge action space, an efficient aDaptive Accept Reject (DART) method is employed, which significantly reduces the regret of CMCR in the detection task. Moreover, a slide‐window change point indicator is proposed to monitor the change of target's RCS, which enables CMCR to be applicable in scenarios where target's RCS varies. Finally, the effectiveness and robustness of CMCR are through extensive numerical experiments. [ABSTRACT FROM AUTHOR]

Accurate subseasonal prediction of heavy rainfall is helpful for disaster mitigation but challenging. The land thermal condition of Tibetan Plateau (TP), usually with climate memory ranging from weeks to seasons, has been seen as a potential predictability source for subseasonal prediction. Aiming at 2020 record‐breaking Mei‐yu rainfall, this study attempts to investigate whether and how the influence of initial TP surface thermal condition near late June influences the July rainfall prediction over the Middle and Lower Yangtze River Region (MLYR), based on two contrasting prediction experiments using a global climate ensemble prediction system. The results show that the most distinguishable change in the downstream prediction in July is the anomalous low‐tropospheric cyclone and the associated increased rainfall over MLYR corresponding to the warmer initial condition of surface TP. Influenced by the invasion of the positive potential vorticity (PV) center that generated over TP and propagated eastward, this low‐level cyclone anomaly over MLYR is formed within the first week of prediction, and persists for the next 3 weeks maintained by the positive feedback between the low‐level cyclone and middle‐tropospheric latent heating over MLYR in the prediction. This study confirmed the significant effect of TP initial thermal condition on downstream prediction ahead of 3 weeks during the Mei‐yu season (peak summer) with strong land–atmosphere coupling over TP. Plain Language Summary: Based on two contrasting prediction experiments using a global climate ensemble prediction system, this study exhibits that changing the initial thermal condition over Tibetan Plateau (TP) surface can significantly influence the subseasonal prediction of rainfall over Middle and Lower Yangtze River Region (MLYR) in Mei‐yu season. After the TP land surface warming at the initial time of prediction, a low‐level cyclonic and increased rainfall appears within the first week of prediction and persists for the next 3 weeks maintained by the positive feedback between the low‐level cyclone and middle‐tropospheric latent heating over MLYR. This study confirmed the effect of initial land thermal condition over TP on the MLYR prediction ahead of 3 weeks during Mei‐yu season (peak summer) with strong land‐atmosphere coupling over TP. Key Points: Initial TP land surface warming can generate a local near‐surface PV positive center and expand downstream within the first prediction weekThe downstream cyclonic anomaly and increased rainfall can be maintained for 3 weeks in prediction by a positive feedbackThe study confirmed the effect of TP initial thermal condition on the MLYR prediction ahead of 3 weeks in Mei‐yu season (peak summer) [ABSTRACT FROM AUTHOR]

Entrainment rates at varying horizontal grid spacing were diagnosed and analyzed based on Large Eddy Model (LES) and Cloud Resolving Model (CRM) simulations of shallow and deep convection. Results show the estimated entrainment rates increase with increasing resolution, and the growth rate is roughly power‐law related to resolution. However, all commonly used parameterizations except for the buoyancy sorting scheme fail to reproduce the monotonic increase of entrainment with resolution, but rather a slight decrease instead. For these schemes, it is suggested the power‐law fitting formula derived from LES/CRM simulations can be used as a scaling function for high‐resolution entrainment correction. Preliminary tests show that the application of entrainment scaling largely reduces the parcel buoyancy and thus the convective available potential energy, favoring the reduction of parameterized convection at high resolution. Plain Language Summary: As model resolution continues to increase with increasing computational power, cumulus convection becomes partially resolved by the model grid, which requires parameterized convection to be reduced with increasing resolution. The purpose of this study is to investigate the scale dependence of entrainment rate, which is an important component in convection parameterization, by using multiple cloud resolving model simulations of shallow and deep convections. It was found that the estimated entrainment rates increase with increasing resolution, but most current entrainment schemes are unable to reproduce the monotonic increase in entrainment rate with increasing resolution. As a result, a scaling factor between entrainment and resolution was derived and suggested for use in correcting parameterized entrainment rates at high resolution. Key Points: The estimated LES/CRM entrainment rates increase with increasing resolution, and the growth rate is roughly power‐law related to resolutionThe majority of entrainment schemes fail to reproduce the monotonic increase in entrainment rate with increasing resolutionEntrainment scaling helps reduce the parcel buoyancy and thus the convective available potential energy toward higher resolutions [ABSTRACT FROM AUTHOR]

The atmospheric circulation around the Tibetan Plateau (TP) exhibits a substantial 10–20‐day quasi–biweekly oscillation (QBWO), profoundly impacting weather and climate locally and remotely. Understanding the factors influencing the generation of QBWO over the TP (QBWOTP) and its physical mechanism is crucial. This study has investigated the influence of multi–timescale and land–atmosphere interactions on the generation of the QBWOTP in surface potential vorticity (SPV), a valuable tool for characterizing the mechanical and thermal variabilities in mountain forcing, based on a 2014 case study. Results indicate that in the free atmosphere, the summer monsoon onset over the Bay of Bengal induces a northward shift in the westerly jet toward the TP, manifested as an increase in low‐frequency zonal winds. This shift facilitates the propagation of wave trains, leading to atmospheric quasi–biweekly potential temperature anomalies (θa) over the TP through a multi‐timescale interaction. Additionally, the TP's surface thermal forcing and arrival of wave trains trigger anomalous upward motion and increase cloud cover. The resultant decrease in net short‐wave radiations and increase in net long‐wave radiations contribute to variations in surface potential temperature (θs) over the TP. As θa and θs evolve, the difference between them enlarges, resulting in the generation of the SPV QBWOTP. Given the relationship between the QBWOTP and downstream rainfall, this study could provide novel insights into understanding and predicting downstream rainfall QBWO. Plain Language Summary: The atmosphere around the Tibetan Plateau (TP) exhibits a substantial 10–20‐day oscillation known as the quasi–biweekly oscillation (QBWO). The QBWO over the TP (QBWOTP) significantly impacts weather and climate both locally and in distant regions, making it crucial to understand its generation. We conducted a case study to understand the QBWOTP and its generation mechanism in surface potential vorticity (SPV), a useful tool for examining the dynamic and thermodynamic variations of the TP. Our results indicate that the summer monsoon over the Bay of Bengal affects the TP by causing a northward shift in the westerly jet, leading to wave train propagation and atmospheric potential temperature variability. The surface thermal forcing of the TP and wave trains influence clouds and surface radiation, causing changes in the surface potential temperature. These combined effect of these processes results in the SPV QBWOTP generation, which has important implications for understanding and forecasting downstream rainfall QBWO. Key Points: SPV QBWOTP is dependent mostly on the vertical difference in the potential temperature (θs–θa)Onset of BOBSM influences the zonal wind, wave trains propagation, thereby θa during SPV QBWOTP generation via multi‐timescale interactionWave trains and TP land–air interaction regulate the surface energy balance, leading to the variation in θs during SPV QBWOTP generation [ABSTRACT FROM AUTHOR]

It is a fundamental problem to analyze the performance bound of multiple‐input multiple‐output dual‐functional radar‐communication systems. To this end, we derive a performance bound on the communication function under a constraint on radar performance. To facilitate the analysis, in this paper, we consider a simplified situation where there is only one downlink user and one radar target. We analyze the properties of the performance bound and the corresponding waveform design strategy to achieve the bound. When the downlink user and the radar target meet certain conditions, we obtain analytical expressions for the bound and the corresponding waveform design strategy. The results reveal a tradeoff between communication and radar performance, which is essentially caused by the energy sharing and allocation between radar and communication functions of the system. [ABSTRACT FROM AUTHOR]

Target localization for distributed radars requires precise knowledge of the calibration errors in time, frequency, and space. Previous studies focus on the sensor location error and sensor directional error in space. This paper concentrates on the system errors in time and frequency which directly affect the targets estimation of range and velocity. Based on linear frequency modulation waveform, the impact of the system errors including sample interval, pulse repetition interval, and centre frequency are analysed. An alternating optimization algorithm is proposed to achieve the target localization, velocity estimation and system errors estimation simultaneously. Simulation shows the effectiveness of the algorithm and the influence on localization due to varying number of targets and radars. [ABSTRACT FROM AUTHOR]

Sub‐seasonal to seasonal (S2S) prediction provides an extended range of lead time for decision‐makers across multiple sectors. S2S forecast is crucial for a country that are susceptible to hydro‐meteorological disasters like Nepal. However, S2S forecast requires assessment with reliable datasets before its application. Since, Nepal lacks a dense station network, multi‐source precipitation estimates (MPEs) are the obvious alternatives. Therefore, using classical evaluation metrics and extreme precipitation indices, this study assessed eleven high‐resolution datasets against 159‐gauge stations over Nepal for the 2001–2020 period. These datasets are classified as gauge‐interpolated (APHRODITE), merged (TPMFD, MSWEP, CLDAS, and CHIRPS), satellite‐based (IMERGV7, IMERGV6, CMORPH, and PERSIANN), and reanalysis (ERA5‐L and HAR). Satellite datasets (except IMERGV7) failed to capture the spatial pattern of mean annual precipitation, while others broadly captured it. Most MPEs struggled to accurately estimate wet season precipitation compared to dry season. Furthermore, increasing estimation error from light to extreme precipitation and decreasing skill metrics from flat to complex terrain, demonstrate the intensity and terrain‐specific limitations of MPEs. In terms of precipitation extremes, APHRODITE exhibits the highest skill, followed by MSWEP, TPMFD, HAR, ERA5‐L, IMERGV7, CLDAS, IMERGV6, CHIRPS, CMORPH, and PERSIANN. IMERGV7 exhibits increased skill in detecting extreme precipitation and precipitation over orography against IMERGV6. APHRODITE and TPMFD datasets performed consistently well in all scales, including weekly anomaly, with an average anomaly correlation of 0.84 and 0.66 respectively. However, since APHRODITE is not widely available, TPMFD can serve as a benchmark dataset for evaluating high‐resolution S2S forecasts within the study region. Plain Language Summary: Timely and accurate forecasts of weather events before their occurrence is important for decision‐makers in effective planning and actions to cope with weather‐induced disasters. Such forecast plays a crucial role in disaster preparedness over complex terrain regions like Nepal. Since sub‐seasonal to seasonal (S2S) scale prediction can provide forecasts beyond 10 days up to 30 days, is getting popular nowadays. However, their skill needs to be evaluated before any operational use which requires reliable observation data. Since, Nepal lacks the proper ground observing stations: mainly over the high mountains, gridded precipitation datasets produced using multiple sources (like satellites, and numerical models) have been good alternatives. Thus, we evaluated 11 such gridded datasets against the existing ground observing stations. We found that these datasets struggle to estimate extreme precipitation. Additionally, they also fail to capture precipitation characteristics over the complex terrain of the high mountain region compared to flat regions. Overall, gauge interpolated and merged datasets demonstrated better performance in estimating precipitation characteristics over complex terrain; hence, can serve as a benchmark dataset for S2S forecast evaluation in this region. Key Points: Multi‐source precipitation estimates captured the annual to weekly precipitation cycle, but only roughly captured the spatial patternMulti‐source precipitation estimates performed poorly in estimating extreme precipitation and struggled over complex terrainAmong high‐resolution datasets, TPMFD has the potential to be used as a reference dataset for sub‐seasonal to seasonal model evaluation [ABSTRACT FROM AUTHOR]

Spring thermal forcing over the Tibetan Plateau (TP) is largely determined by surface sensible heating (SSH), which is an important fuel for atmospheric circulations over subtropics and even the globe. However, insufficient efforts were devoted on exploring the potential influencing factors of spring TP's SSH. In the current study, observational analysis and model results confirm that the sea ice concentration in the north of Greenland can act as a precursor. Specifically, the winter shrinkage of the sea ice concentration can stimulate a meridional Rossby wave train, with a remarkable positive‐negative‐positive pattern of geopotential height anomalies controlling the Arctic, western Eurasia, and the southeastern Mediterranean, respectively. This teleconnection is equivalent barotropic in the whole troposphere, which shifts southeastward from winter to spring, with a significant anomalous anticyclone and increased geopotential height dominating the western TP in spring. The surface northeasterly anomalies in the southeastern flank of the anticyclone decrease the climatological westerlies and weaken the SSH over the central‐southern TP. Existing literature mainly focused on the Arctic‐TP relationship in autumn and winter. Our finding can not only provide a new insight onto the variation of spring thermal condition over the TP, but also deepen our knowledge of cross‐seasonal relationships between the Arctic and the TP with similar snow‐ice albedo feedback. Plain Language Summary: Surface sensible heating (SSH) over the Tibetan Plateau (TP) in spring can modulate subsequent Asian summer monsoon system and even the winter El Niño–Southern Oscillation events, and then exert profound impacts on the global ecosystems and human livelihoods. However, less attention has been paid on exploring its potential influencing factors. Relationships between the Arctic and the TP have gained increasing popularities in recent decades. However, plentiful studies concentrated on the Arctic‐TP connections in autumn and winter. Investigations on whether the preceding Arctic sea ice can modulate spring TP's SSH remain inadequate. This study reveals a close linkage between winter sea ice concentration (SIC) in the north of Greenland and subsequent spring TP's SSH. Specifically, diminished (enhanced) winter SIC can generate a Rossby wave train extending along the Arctic, western Eurasia, and the western TP, resulting in decreased (increased) spring TP's SSH. This finding is expected to bridge the cross‐seasonal gap of the Arctic‐TP relationship. Key Points: A cross‐seasonal linkage exists between winter sea ice over the north of Greenland and spring thermal condition over the TPThe linkage is established through a Rossby wave train extending along the Arctic, western Eurasia, and the western TPThe anticyclonic anomalies induced by the Rossby wave train weaken surface wind speed and thermal condition over the central‐southern TP in spring [ABSTRACT FROM AUTHOR]

The zonal‐mean subtropical westerly jet (SWJ) in boreal winter shows a significant northward shift trend under recent climate change. Previous studies proposed thermal forcing—represented by the thermal wind associated with the temperature gradient—and the driving effect of the eddy momentum flux (EMF) convergence that leads to the eddy‐driven jet as explanations for this process; however, their relative importance in influencing the SWJ shift requires further investigation. In this study, we examined the roles of thermal forced and eddy‐driven jet components in the zonal‐mean northward SWJ shift. We also investigated the role of Hadley circulation because its poleward boundary is related to the zonal‐mean SWJ. Results suggest that thermal forced component plays a major role, while EMF‐driven component plays a secondary role. Specifically, the subtropical warming, which is primarily influenced by enhanced adiabatic downward motion of the Hadley circulation, increases the meridional temperature gradient and the associated thermal wind poleward of the SWJ. It also reduces atmospheric static stability aloft and converges the EMF on the poleward side of the climatological SWJ. Enhanced meridional temperature gradient and EMF convergence on the poleward side push the SWJ northward. Results from further mathematical analysis indicate that thermal forced and eddy‐driven zonal wind components account for 72% and 28% of the shift distance, respectively. In addition to elucidating the relative importance of thermal and EMF forcings, this study emphasizes the critical role of the subtropical warming driven by the intensified local descending branch of the Hadley circulation in shifting the zonal‐mean SWJ. Plain Language Summary: Both the thermal forced and eddy‐driven perspectives are widely used in literature to understand the northward shift of subtropical westerly jet (SWJ) under climate change. The former is related to the temperature structure, while the latter is related to the eddy momentum flux convergence. This study aims to investigate their relative importance in the northward shift of SWJ. By using a simple decomposition, this study shows that the subtropical westerly jet can be viewed as the sum of the thermal forced and eddy‐driven jet components. Results suggest that the thermal forced effect plays a major role in shifting the SWJ, while the eddy‐driven effect plays a secondary role. Here, it should be pointed out that the term thermal forced jet in this study refers in particular to the jet induced by the meridional gradient of temperature field, which is different from the term thermally driven jet caused by diabatic heating in some studies. This study can help readers grasp the main processes in understanding the SWJ shift, and therefore can be used in fields such as emergent constraints, that is, using the thermal forced jet to constrain the future projection of the SWJ. Key Points: The thermal forced (eddy‐driven) wind plays a major (secondary) role in shifting the subtropical westerly jet under recent climate changeThermal forced and eddy‐driven effects are related to subtropical warming which mainly comes from the enhanced adiabatic sinking motion [ABSTRACT FROM AUTHOR]

We compared short‐term cloud feedback, defined at the top of the atmosphere (TOA), the atmospheric column (ATM), and the surface (SFC), between observations and models participating in Atmospheric Model Intercomparison Project Phase 6 (AMIP6) for the period 2000–2014. The globally averaged net cloud feedbacks observed at TOA, ATM, and SFC are −0.06 ± 0.63, −0.17 ± 0.70, and 0.11 ± 0.81 W m−2 K−1, respectively. While most models produced TOA cloud feedbacks that agreed with the observations within uncertainty ranges, the intermodel spread at SFC and within ATM was relatively larger. This demonstrates that models are diverse in how their TOA feedback is distributed between ATM and SFC. Because short‐term cloud feedback is mainly driven by El Niño–Southern Oscillation (ENSO), the global‐mean cloud feedback was further decomposed into components from the ENSO and non‐ENSO regions. Results show that cloud feedback in these two regions tends to be inversely related. Compared to observations, almost all models overestimated the longwave cloud feedback in the ENSO region due to the overestimation of cloud amount changes for high‐topped clouds. For these models, it is the offset between deviations in ENSO and non‐ENSO regions that leads to the overall agreement of global mean with observations. Sensitivity tests show that the main conclusions still hold when alternative kernels are used in estimating cloud feedback. Plain Language Summary: The large spread in cloud feedback among climate models contributes to the largest uncertainty in climate sensitivity. There is an urgent need to utilize observational data to validate cloud feedback in climate models. By using a combination of reanalysis data and satellite measurements for the period 2000–2014, results show the observed cloud feedback at TOA, ATM, and SFC is −0.06 ± 0.63, −0.17 ± 0.70, and 0.11 ± 0.81 W m−2 K−1, respectively. Most models produced TOA cloud feedback that was consistent with observations within the uncertainty range, yet there was larger difference at the surface and within the atmosphere, causing some models to produce values outside the uncertainty range. Further study shows that even well‐modeled TOA feedback is due to bias offsetting. The models tend to overestimate longwave cloud feedback in the El Niño–Southern Oscillation (ENSO) region due to an overestimation of high‐topped cloud changes, which is partially offset by an underestimation in the non‐ENSO region, resulting in a global mean that is close to the observed value. Decomposing cloud response and cloud feedback in this way highlights the deficiency in ENSO‐related cloud modeling that would otherwise be hidden by the global average. Key Points: The intermodel spread of the net short‐term cloud feedback is larger at the surface and within the atmosphere than at the top of atmosphereAn inverse relationship between cloud feedbacks in the El Niño–Southern Oscillation (ENSO) and non‐ENSO regions is found in both observations and AMIP6 modelsCompared to observations, models tend to overestimate longwave cloud feedback in ENSO regions due to the overestimation of high‐topped cloud [ABSTRACT FROM AUTHOR]

This study identifies the relationship between tropical southern Atlantic (TSA) sea surface temperature anomaly (SSTA) and the El Niño‐Southern Oscillation (ENSO) and focuses on how the Pacific Decadal Oscillation (PDO) modulates this relationship. Results suggest a significant but non‐stationary interannual TSA‐ENSO relationship which undergoes a significant decadal shift. A strong TSA‐ENSO relationship is observed during the positive PDO phase, while this relationship is weak during the negative PDO phase. Two processes, involving the anomalous Pacific Walker circulation (PWC) and the intensity of air‐sea interactions over the Pacific, are proposed for this decadal shift. During the positive PDO phase, the weak and variable PWC and strong air‐sea interaction facilitate the development of SSTA in the tropical Pacific triggered by TSA SSTA, resulting in a strong TSA‐ENSO relationship and vice versa. These findings emphasize the important role of the modulation of PDO on the TSA‐ENSO relationship. Plain Language Summary: The present study finds a significant TSA‐ENSO relationship that anomalous warm (cold) TSA sea surface temperature (SST) in the preceding winter is closely linked to the cold (warm) ENSO in the subsequent summer and winter. However, the TSA‐ENSO interannual relationship is non‐stationary, which is strong during the positive PDO phase and weak during the negative PDO phase. Two processes responsible for this non‐stationary relationship are proposed. During the positive PDO phase, the weak and variable PWC is more susceptible to the TSA forcing, resulting in a strong TSA‐ENSO relationship. Meanwhile, the strong air‐sea interaction in the tropical Pacific also facilitates the development of SSTA triggered by TSA SSTA, leading to a strong and robust TSA‐ENSO relationship. During the negative PDO phase, the situations of PWC and air‐sea interaction are opposite and thus lead to a weak TSA‐ENSO relationship. These findings could help to improve our understanding of the decadal variability of the ENSO evolution. Key Points: The relationship between tropical southern Atlantic (TSA) SST and subsequent El Niño‐Southern Oscillation (ENSO) is stronger in positive Pacific Decadal Oscillation (PDO) than in negative PDOIn positive PDO, the TSA SST anomaly easily exerts an impact on ENSO because of a weaker and more variable Walker circulationIn positive PDO, the stronger air‐sea interaction over the tropical Pacific facilitates the maintenance of local SST and wind anomalies [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP) impacts local and remote atmospheric circulations, wherein it mechanically and thermally affects air masses or airflows. Moreover, the TP provides a key channel for substance transport between the troposphere and the stratosphere. This study reviews recent advances in research regarding land–atmosphere coupling processes over the TP. The TP experiences climate warming and wetting. Climate warming has caused glacier retreat, permafrost degradation, and a general increase in vegetation density, while climate wetting has led to a significant increase in the number of major lakes, primarily through increased precipitation. Local and regional climates are affected by interactions between the land and the atmosphere. Namely, the TP drives surface pollutants to the upper troposphere in an Asian summer monsoon (ASM) anticyclone circulation, before spreading to the lower stratosphere. Further, the thermal forcing of the TP plays an essential role in the ASM. TP forcing can modulate hemispheric‐scale atmospheric circulations across all seasons. The TP interacts with remote oceans through a forced atmospheric response and is substantially affected by the evolution of the Earth's climate via promoting Atlantic meridional overturning circulation and eliminating Pacific meridional overturning circulation. The extensive influence of the TP is facilitated by its coupling with the ASM in the summer; whereas its winter influence on climate mainly occurs through Rossby waves. The observed increasing trends of temperature and precipitation over the TP are projected to continue throughout the 21st century. Plain Language Summary: The impact of the Tibetan Plateau on atmospheric circulation and the climate has been of great interest to the scientific community. Here, we review the literature on the mechanisms of its climate effects, to provide an overview of recent progress in the field and directives for future research. Key Points: We summarize recent advances in climate change research and observations of the land–atmosphere coupling processes over the Tibetan Plateau (TP)We highlight the impact of the TP on the global climate, including atmospheric species transport, circulation, and air‐sea interactionsWe conclude projected future climate changes over the TP and discuss future research directives for assessing the TP's global climate impact [ABSTRACT FROM AUTHOR]

Simultaneously localization and mapping (SLAM) has been widely used in autonomous mobile systems to fulfill autonomous navigation. Relocalization plays an important role in SLAM for closing the loop and eliminating the drift of pose estimation. Traditional methods mostly rely on LiDAR or camera sensors, which may degrade or even fail in rainy or dusty situations or with large illumination changes. In this article, we explore the use of low‐cost commercial millimeter wave (mmWave) radars and propose a noval mmWave radar point cloud‐based relocalization method. Our method first pre‐processes the radar point cloud and, based on that, achieves fast 3‐DOF pose estimation for the robot. We build a prototype and thoroughly evaluate our method using data sets collected by our platform in four complex environments, including street, park, road, and water surface scenarios. The experimental results show that our method consistently outperforms other baseline methods including the vision‐based counterparts, especially in the visual degraded scenes. [ABSTRACT FROM AUTHOR]

Salvage treatment of locoregionally recurrent nasopharyngeal carcinoma (NPC) requires weighing the benefits of re‐irradiation against increased risks of toxicity. Here, we evaluated the outcomes of patients treated with intensity‐modulated‐based pulsed low‐dose‐rate radiotherapy (PLDR‐IMRT) to enhance the curative effect of salvage treatment and reduce RT‐related SAEs. A prospective clinical trial was conducted from March 2018 to March 2020 at multiple institutions. NPC patients who experienced relapse after radical therapy were re‐irradiated with a median dose of 60 Gy (50.4–70 Gy)/30 f (28–35 f) using PLDR‐IMRT. Thirty‐six NPC patients who underwent PLDR‐IMRT for locoregional recurrence were identified. With a median follow‐up of 26.2 months, the objective response rate (ORR) of the entire cohort was 91.6%. The estimated mPFS duration was 28 months (95% CI: 24.9–31.1), and the estimated mLRFS duration was 30.4 months (95% CI: 25.2–35.5). The overall survival (OS) rate for all patients was 80.6%, the progression‐free survival (PFS) rate was 75% and the cancer‐specific survival (CSS) rate was 88.9% at 1 year. The LRFS and DMFS rates were 88.9% and 91.7%, respectively, at 1 year. A combination of systematic therapies could provide survival benefits to patients who experience NPC relapse (p < 0.05), and a Karnofsky performance status (KPS) score of ≥90 was a favorable factor for local control (p < 0.05). The incidence of acute SAEs (grade 3+) from PLDR was 22.2%, and the incidence of chronic SAEs was 19.4% among all patients. PLDR‐IMRT combined with systematic therapy can effectively treat patients with locoregionally recurrent nasopharyngeal carcinoma and causes fewer adverse events than the rates expected with IMRT. [ABSTRACT FROM AUTHOR]

To aid the understanding of atmospheric circulation climatology over the Tibetan Plateau (TP), this study investigated the comprehensive potential vorticity (PV) budget over the TP using model‐level reanalysis data. Our findings demonstrate the effects of diabatic heating, friction, gravity wave drag, advection, and convection in determining circulation over the TP, from the PV budget perspective. In summer, the diabatic heating‐generated positive (negative) PV tendency facilitates cyclonic (anticyclonic) circulation near the surface (in the middle troposphere). Low PV in the upper troposphere, pertaining to the Asian monsoon anticyclone and monsoonal overturning circulation is induced by the upward transportation of diabatic heating‐generated low PV in the middle troposphere. Horizontal advection further spreads the low PV—that is vertically inputted from the middle troposphere—to a wide area around the TP in the upper troposphere. In winter, the diabatic heating‐generated positive PV near the surface is balanced by the sinking motion‐carried low PV. In addition, gravity wave drag‐generated PV is prominent in the upper troposphere in winter and can affect the downstream climate through advection. We further revealed the crucial role of the diurnal cycle in shaping the near‐surface cyclonic circulation in summer by regulating the vertical structure of diabatic heating. [ABSTRACT FROM AUTHOR]

Sea surface temperature anomalies (SSTAs) over the North Atlantic could stimulate the El Niño–Southern Oscillation (ENSO) events through regulating the tropical and mid‐latitude atmospheric circulations. Whether the Tibetan Plateau (TP) play an important bridging role in the mid‐latitude pathway has been rarely considered. Observational analysis and model simulations show that the spring TP surface wind speed dipole mode forced by the winter–spring North Atlantic tripole SSTAs can induce surface zonal wind anomalies over the equatorial western Pacific from April to June through the Indo‐Pacific gearing process, favoring the occurrence of subsequent autumn–winter ENSO events through the Bjerknes feedback. Moreover, a flattened TP will obviously weaken the atmospheric and oceanic responses associated with ENSO development to the North Atlantic tripole SSTAs forcing. Quantitatively, the TP's bridging effect accounts for about 38% proportion in the above process. Our finding provides a new insight in understanding the mid‐latitude pathway. Plain Language Summary: El Niño‐Southern Oscillation (ENSO) exerts pronounced climate impacts across the globe, but it is influenced by many factors. Previous studies have revealed that sea surface temperature anomalies (SSTAs) over the North Atlantic could stimulate ENSO events through two pathways, directly through regulating the tropical atmospheric circulation and indirectly via stimulating the mid‐latitude atmospheric teleconnection. In the indirect pathway, the physical mechanisms involve very complex interactions among multiple atmospheric and oceanic systems. Here, we reveal that the Tibetan Plateau (TP) plays an important bridging role in the indirect pathway. Both observations and model simulations show that winter‐spring positive North Atlantic tripole SSTAs can trigger downstream‐propagating Rossby wave train, which further cause an upper‐level anomalous cyclone (anticyclone) over the western TP (subtropical central‐western Pacific) during April and June. Consequently, upper‐level convergences and lower‐level divergences appear over the Maritime Continent, which induce surface westerly anomalies over the equatorial western Pacific, favoring the occurrence of subsequent autumn‐winter El Niño events. After flattening the TP in climate model, the overall responses of atmospheric and oceanic processes associated with El Niño development to the North Atlantic tripole SSTAs will be obviously weakened. Quantitatively, the TP's bridging effect accounts for about 38% contribution in the above process. Key Points: The spring Tibetan Plateau (TP) thermal forcing could act as a medium in linking the preceding North Atlantic tripole Sea surface temperature anomalies (SSTAs) and the subsequent El Niño–Southern Oscillation (ENSO) eventsExcluding the TP's effect will weaken the responses of processes associated with ENSO development to the North Atlantic tripole SSTAs forcingQuantitatively, the TP's bridging effect accounts for about 38% proportion in the above process [ABSTRACT FROM AUTHOR]

The spatial pattern of intermodel spread of surface temperature (TS‐SPREAD) is similar to the absolute error of modeled surface temperature relative to observations, implying the possibility of using intermodel spread to understand the model biases. The regions with maximum TS‐SPREAD are located in the northern polar (NP) and southern polar (SP) regions, and regions with the large orographic features, such as the Tibetan Plateau (TP). We find: (a) Winter amplification exists in the TS‐SPREAD over both the NP and SP regions, but the maximum TS‐SPREAD over the TP happens during spring and summer with weak seasonality there. (b) Surface energy balance analyses show salient land‐sea contrast in the interlinkage between the physical processes. (c) Over the Arctic Ocean and the Southern Ocean, the maximum spreads of sea‐ice‐induced surface albedo appear during summer when the TS‐SPREADs are the weakest because the effect of surface albedo is offset by the heat storage in the oceans. (d) Through the interseasonal linkage of the heat storage term, i.e., the summer‐storing‐winter‐releasing of oceanic heat content, the summer surface albedo may indirectly contribute to the winter amplification of the TS‐SPREAD over the polar oceans. Such interseasonal linkage of the processes does not exist over the land areas. A method of distinguishing the roles of the local and nonlocal dynamical processes in the contribution of the clear‐sky downward longwave radiation to the TS‐SPREAD is also provided. Plain Language Summary: Understanding the origin of climate model biases is essential to the projection of future climate change, and it is very hard task for the climate modeling community. Here, we show that there exists similarity in the spatial patterns of the intermodel spread, mean absolute errors, and absolute mean errors of surface temperature simulations in climate ensembles. Therefore, we may use the intermodel spread to help understand the mean model biases. We find the regions with maximum surface temperature spread (TS‐SPREAD) are mainly located in the northern polar (NP) and southern polar (SP) regions, and regions with large orographic feature, such as the Tibetan Plateau, indicating the polar and topographic amplifications of TS‐SPREAD in climate models. In the paper, we reveal the process‐chains that lead to the spatial pattern and seasonality of amplified TS‐SPREAD over these regions. We suggest that sea‐ice contributes to the TS‐SPREAD over the NP and SP oceans, not in a direct way, but by its coupling with ocean storage, interseasonal heat release through turbulent fluxes, and also the horizontal heat transport, both across the border of and inside the polar regions. The findings may help climate modelers to improve their models. Key Points: The pattern‐similarity among intermodel spread, mean absolute bias, and absolute mean bias enable us to use the former to understand the latter twoThe interseasonal linkage between surface albedo, heat storage, turbulent fluxes, and dynamical transport causes winter amplification over polar oceansA method is provided to determine the local versus nonlocal contributions to surface downward longwave radiation [ABSTRACT FROM AUTHOR]

Temperature variations across the continental northern hemisphere at the interdecadal scale are thought to be remotely modulated by oceanic internal climate variability and the Arctic. Nevertheless, further elucidating the dynamics is essential for clarifying ongoing debates. We show that potential vorticity (PV) dynamics provide a concise explanation for these teleconnections. Our findings demonstrate that extratropical oceans and the Arctic can remotely modulate the wintertime continental temperature variations by stimulating PV anomalies, which are constrained by climatological PV gradients and jet streams. A causal explanation includes anomalous temperature and precipitation over oceans and the Arctic inducing local PV anomalies via diabatic heating. Subsequently, meridional and downstream advection distributes the anomalous PV to remote land regions where the climatological PV gradients are strong, that is, involving PV fronts, as well as jet streams; therefore, PV fronts and jet streams jointly indicate land regions that are largely and frequently impacted. However, land can also modulate other regions through the same mechanism when variations over land occur in advance. Clear causality depends on which factor is independent, while interactions among those regions may convolute the causality, thereby causing further debates. Plain Language Summary: Studies have indicated the crucial influences of both the oceanic internal climate variability and the Arctic on regional wintertime temperature variations across the continental northern hemisphere at the interdecadal scale. However, a concise explanation of the underlying mechanisms is necessary, especially when causality in the Arctic and mid‐latitude connections is under debate. We show that potential vorticity (PV) dynamics can provide a lucid viewpoint. In particular, the findings demonstrate that PV fronts (i.e., regions with strong climatological PV gradients) and jet streams jointly constrain the land regions that are most influenced by oceans and the Arctic. This PV perspective can be applied to general teleconnections over a wide frequency range. Key Points: A PV perspective concisely explains how extratropical oceans and the Arctic remotely influence the land temperaturePV fronts and jet streams jointly constrain the preferred land regions influenced by oceans and the ArcticThe PV perspective holds for both mean climate change and high‐frequency weather variability [ABSTRACT FROM AUTHOR]

The critical relative humidity (RHc), which approximately measures the subgrid‐scale variability of moisture, is important to cloud parameterization. Based on the diagnostics from CloudSat/CALIPSO satellite data, we propose an improved RHc formula that incorporates geographic dependence and allows for non‐monotonic variations in the vertical. With the parameterized RHc, a cloud macrophysics scheme is constructed in which fractional cloudiness and subgrid‐scale condensation are synergistically solved, with the latter being calculated using two different approaches. Results show the new scheme largely alleviates the underestimation of high‐ and mid‐level clouds in the default model. The performance is also superior to the simulations applying a globally uniform RHc as conventionally used in the literature. Varying RHc and the techniques for computing subgrid‐scale condensation leads to a marked diversity in cloud feedback, which nearly replicates the range of uncertainty found in Coupled Model Intercomparison Project Phase 6 models. Using smaller RHc leads to larger spread than using larger ones. And the spread caused by different techniques for calculating subgrid‐scale condensation is larger than that caused by the choice of RHc. While many previous studies have emphasized the diversity of cloud feedback due to low clouds, varying RHc and its implementation leads to diversity of cloud feedback being mainly due to optically thick clouds. These results highlight the importance of RHc in inducing uncertainty of cloud feedback, as well as notes of caution to modelers when using RHc to tune models. Plain Language Summary: To represent subgrid‐scale cloud condensation in climate models, information on fluctuations of temperature and moisture within a grid is indispensable. By neglecting temperature fluctuations and assuming that the probability density function of total water is uniform, the subgrid‐scale variability of moisture is reduced to the so‐called "critical relative humidity" (RHc). Previous parameterizations assume RHc is globally uniform and varying monotonically in the vertical, which is far from realistic. Based on the diagnostics from CloudSat/CALIPSO satellite data, we propose an improved RHc formula that incorporates geographic dependence and allows for non‐monotonic variations in the vertical. A RHc‐based cloud macrophysics scheme is then constructed to investigate the role of RHc on cloudiness simulation and cloud feedback. Results show varying RHc and the techniques in calculating subgrid‐scale condensation nearly replicates the range of uncertainty found in CMIP6 cloud feedback estimates, thus raising caveats for modelers given that RHc is commonly used as a knob for model tuning. Key Points: We propose an improved critical relative humidity (RHc) formula that incorporates geographic dependence and allows for non‐monotonic variations in the verticalVarying RHc and techniques in calculating subgrid condensation replicates the range of uncertainty found in Coupled Model Intercomparison Project Phase 6 cloud feedback estimatesVarying RHc and its implementation in models leads to the diversity of cloud feedback being mainly due to optically thick clouds [ABSTRACT FROM AUTHOR]

The simulation skills of the Southern Annular Mode (SAM) pattern for the CMIP6 models are evaluated in this study. Both the Atmospheric Model Intercomparison Project (AMIP) and historical experiments are utilized to understand the effect of SST forcing and air–sea interaction. The spatial correlation coefficient, standard deviation, and root‐mean‐square error (RMSE) are used as the objective metrics. The results suggest that the multimodel mean (MME) for both AMIP and historical data could capture the basic spatial patterns of the SAM for all seasons, featuring the opposite sign between the middle and high latitudes with a zonal three‐wave structure in the middle latitudes (positive phase). However, the overall skill of the AMIP simulation is higher than that of the historical simulation, which could be attributed to realistic SST forcing being applied. The simulation skill varies for different seasons: the skill for boreal spring (March–May [MAM]) is the lowest, while it is highest in boreal winter (December–February [DJF]). Further analysis shows that the simulations of the SAM asymmetric part are the key component for the simulation of the spatial pattern of the SAM, especially sensitive in MAM. The wave–current interaction simulation at mid–high latitudes is suggested to be improved for the advancement of SAM simulations in future model development. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP) is an important forcing in the global climate system. Compared to the extensive studies on the influence of the TP on surrounding climates, the variability of the surface potential vorticity (PV) over the TP (TPSPV) in response to other forcings is seldom discussed. In this article, the influence of the interannual mode of North Atlantic tripole sea surface temperature (NAT) on the TPSPV during boreal summer is investigated. Results show that the negative (positive) anomalous TPSPV is associated with anomalous unstable (stable) surface air, cyclonic (anticyclonic) surface circulation, and rising (sinking) motion, which favors the stronger (weaker) East Asian summer monsoon and weaker (stronger) Indian summer monsoon. Further analysis indicates that the negative TPSPV is significantly correlated with a positive NAT mode with a cold center in the middle and warm centers in the subtropic and subpolar regions. This relationship is further testified by numerical experiments. The results further demonstrate that the positive NAT forcing can stimulate a Rossby wave train aloft, which passes Scandinavia, Ural and arrives at the TP and eventually triggers a low‐level positive PV over the TP. Constrained by the PV‐θ mechanism, the low‐level positive PV favors a decrease in static stability near the surface and thus leads to a negative TPSPV. Under the positive feedback between TPSPV and vertical motion, the negative TPSPV could further strengthen. Therefore, the positive NAT phase could intensify the thermal and dynamic forcings of the TP in association with TPSPV during boreal summer. Key Points: Leading variation in surface potential vorticity (PV) over the Tibetan Plateau (TP) is closely related to the TP's thermal and dynamic forcings during summerThe North Atlantic tripole sea surface temperature (SST) mode could influence surface PV over the TP via Rossby wave, PV‐θ mechanism, and local positive feedbackThe middle center in the tripole SST mode is critical in triggering the Rossby wave train affecting the TP [ABSTRACT FROM AUTHOR]

The problem of high‐resolution direction finding is considered using a distributed array network with array position errors, called partly calibrated array. These errors are common in practice, and significantly affect high angular resolution. Existing calibration methods rely on centralized data transmission, which requires all the measurements to be transmitted to a computation center. This centralized mode leads to communication bottlenecks and system inflexibility. Here, a decentralized mode is designed, where each sensor only communicates locally with their neighboring sensors. Based on this mode, a corresponding direction‐finding approach is proposed using sequential methods that process data one by one, which corresponds to the decentralized signal processing sensor by sensor. Simulations verify that the proposed method achieves decentralization with minor cost in estimation accuracy.We consider high‐resolution direction finding using distributed arrays with position errors between subarrays. Existing methods are based on centralized mode, which has communication bottlenecks and system inflexibility. Here, we propose a decentralized algorithm to solve this problem. [ABSTRACT FROM AUTHOR]

Using observational analysis and numerical experiments, we identify that the dipole mode of spring surface wind speed (SWS) over the Tibetan Plateau (TP) could act as a trigger for subsequent winter El Niño–Southern Oscillation events. During the positive phase of spring SWS dipole mode (south‐positive and north‐negative), a self‐sustaining "negative sensible heating–baroclinic structure" prevails over the western TP, which is characterized by negative surface sensible heating anomalies, anomalous low‐level anticyclones, and mid–high‐level cyclones. The "negative sensible heating–baroclinic structure" stimulates the surface westerly wind anomalies over the tropical western Pacific in May through two pathways, favoring the occurrence of subsequent El Niño events. One is through weakening the zonal monsoon circulation over the tropical Indian Ocean and the Walker circulation over the tropical western Pacific. The other is modulating the air–sea interaction over the North Pacific through triggering Rossby waves. The negative SWS dipole mode tends to induce La Niña events. Plain Language Summary: El Niño–Southern Oscillation (ENSO) can exert pronounced climate impacts over the tropical Pacific and other remote regions. Meanwhile, the occurrence of ENSO events is also affected by local tropical Pacific and non‐local factors. As an elevated, huge, and intense heat source over the subtropics, Tibetan Plateau (TP) thermal forcing exerts significant influences on atmospheric circulations and oceans across the whole globe. This study explores the impact of spring TP thermal forcing on the formation of ENSO in following winter. In the observations, the south–north dipole modes of spring surface sensible heating and surface wind speed over the TP can stimulate the surface zonal wind anomalies over the tropical western Pacific in May through two pathways, favoring the occurrence of subsequent ENSO events. One is through influencing the zonal monsoon circulation over the tropical Indian Ocean and the Walker circulation over the tropical western Pacific. The other is modulating the air–sea interaction over the North Pacific through triggering Rossby waves. These two pathways are well reproduced in numerical experiments. Key Points: Spring positive surface wind speed (SWS) dipole mode over Tibetan Plateau is closely connected with a "negative sensible heating‐baroclinic structure"Spring positive SWS dipole mode induces winter El Niño by modulating surface westerly wind anomalies over tropical western Pacific in MaySurface westerly wind anomalies over tropical western Pacific in May are induced through gearing between the Indian and Pacific oceans and seasonal footprinting mechanism processes [ABSTRACT FROM AUTHOR]

In this study, a new index based on the potential vorticity (PV) framework is proposed for the quantification of the Tibetan Plateau (TP) surface thermodynamic and dynamic forcing. The results show that the derived TP surface PV (SPV) includes the topographical effect, near‐surface absolute vorticity, and land–air potential temperature differences. The climatological annual cycle of the SPV suggests that the TP transitions from a cooling to a heating source in April. The SPV reaches a maximum from June to August, which is consistent with the evolution of the Asian summer monsoon precipitation. Further analysis suggests that the intensified SPV in the boreal summer results in a low‐level cyclonic circulation anomaly associated with increased precipitation over the southeastern slope of the TP and South China and decreased precipitation over the Indian Ocean. In winter, the intensified SPV is associated with local cold air and divergence at the TP surface. Plain Language Summary: The thermal forcing of Tibetan Plateau (TP) has long thought to be important in regulating the Asian summer monsoon. However, the surface sensible heat flux cannot represent the total thermodynamic forcing of the TP because the SSHF decreases when the monsoon precipitation intensifies during the prevailing Asian summer monsoon season. In this study, we propose a new index based on the potential vorticity (PV) framework, which can be used to quantify seasonal and interannual variations in the TP's surface thermodynamic and dynamic forcing. The results show that the proposed index can represent the TP surface‐elevated heating effect during the boreal summer, which is consistent with those of numerical experiments performed in previous studies. The new index can be used as a metric for model evaluation and climate characterization in future studies to quantify the role of the TP in global climate change. Key Points: The Tibetan Plateau surface potential vorticity index (TP‐SPVI) includes the effects from orographic thermal and dynamical forcingThe seasonal variation in the proposed TP‐SPVI is consistent with the time evolution of the Asian summer monsoon precipitationThe surface PV can be used as a metric for the identification of the TP surface forcing in reanalysis data and for model evaluation [ABSTRACT FROM AUTHOR]

Flexible DC and AC transmission lines can be arranged across vertically or sharing transmission corridor. Under this condition, the possibility of intersystem fault increases significantly, which endangers the safety of both DC and AC systems. Here, the intersystem fault between bipolar half‐bridge MMC‐HVDC system and AC system is analysed. The reliability of DC wavefront protection after intersystem fault is analysed based on initial traveling wave, while the reliability of DC intersystem fault protection and AC protection is analysed based on 50 Hz component characteristics. Since wavefront protection cannot be guaranteed to operate reliably, intersystem fault protection based on 50 Hz components is applied to DC system to reliably detect intersystem faults and isolate the fault by commanding DC circuit breaker to trip. Although current differential relaying and zero‐sequence overcurrent relaying in AC system can reliably detect intersystem faults, a large DC offset prevents effective fault isolation of AC circuit breaker. This highlights the necessity of MMC‐HVDC system to reliably isolate intersystem faults. [ABSTRACT FROM AUTHOR]

Insulin resistance (IR) is a pathogenic factor in numerous metabolic diseases. The gut microbiota plays a crucial role in maintaining the function of the intestinal barrier and overall human health, thereby influencing IR. Dysbiosis of the gut microbiota can contribute to the development of IR. Therefore, it is essential to maintain a balanced and diverse gut microbiota for optimal health. Akkermansia muciniphila, a widely present microorganism in the human intestine, has been shown to regulate gastrointestinal mucosal barrier integrity, reduce endotoxin penetration, decrease systemic inflammation levels, and improve insulin sensitivity. Reduced abundance of A. muciniphila is associated with an increased risk of IR and other metabolic diseases, highlighting its correlation with IR. Understanding the role and regulatory mechanism of A. muciniphila is crucial for comprehending IR pathogenesis and developing novel strategies for preventing and treating related metabolic disorders. Individual variations may exist in both the gut microbiota composition and its impact on IR among different individuals. Further investigation into individual differences between A. muciniphila and IR will facilitate advancements in personalized medicine by promoting tailored interventions based on the gut microbiota composition, which is a potential future direction that would optimize insulin sensitivity while preventing metabolic disease occurrence. In this review, we describe the physiological characteristics of A. muciniphila, emphasize its roles in underlying mechanisms contributing to IR pathology, and summarize how alterations in its abundance affect IR development, thereby providing valuable insights for further research on A. muciniphila, as well as new drug development targeting diabetes. [ABSTRACT FROM AUTHOR]

Using a variety of CloudSat/CALIPSO products, this study synergistically examines the performance of clouds and their radiative effects (CRE) for models participating in CMIP6. Results show virtually all models overestimate the net cooling effect of clouds, which is caused by the overestimation of shortwave CRE and the underestimation of longwave CRE. By dividing clouds into regimes jointly sorted by cloud water path and cloud cover, we found models commonly underestimate the relative frequency of occurrence (RFO) for clouds that are geometrically thick, and the bias of RFO is dominant over that of within‐regime CRE in an error decomposition of total CRE. This results in underestimations of CRE in geometrically thick clouds, which are partially offset by overestimations in the remaining cloud regimes, leading to the globally averaged CRE being less biased. The consideration of regime‐based CRE gives important information that could be used for correction of cloud parameterization in models. Plain Language Summary: A large degree of uncertainty in climate modeling remains in the poor representation of clouds and their radiative effects (CRE). Different from conventional studies that evaluate simulated clouds and CRE using observations from separate data sets, this study utilizes various CloudSat/CALIPSO products, which treat clouds and CRE in a consistent manner, to synergistically examine the performance of clouds and CRE in CMIP6. Moreover, we evaluate model behaviors using a regime‐based approach that segregates clouds into a series of categories according to cloud cover and cloud water path. Results show models struggle to reproduce the within‐regime CRE and the relative frequency of occurrence within individual cloud regimes as in CloudSat/CALIPSO, although the simulation of globally averaged CRE is less biased. This is due to error compensations among different cloud regimes. The consideration of regime‐based CRE gives additional information that could be used for correction of cloud radiation in models. This study underscores the need to constrain or tune models in terms of regime‐based CRE rather than the globally averaged one such that the degrees of model freedom can be reduced. Key Points: CMIP6 models commonly overestimated the net cooling effect of clouds, which is caused by overestimated SWCRE and underestimated LWCREModels commonly underestimated the relative frequency of occurrence (RFO) for clouds that are geometrically thickThe bias of RFO is dominant over that of the within‐regime mean cloud radiative effects (CRE) in an error decomposition of total CRE [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes (SPEs) that can offer flexible processability, highly tunable chemical functionality, and cost effectiveness are regarded as attractive alternatives for liquid electrolytes (LE) to address their safety and energy density limitations. However, it remains a great challenge for SPEs to stabilize Li+ deposition at the electrolyte–electrode interface and impede lithium dendrite proliferation compared with LE‐based systems. Herein, a design of solid‐state fluorinated bifunctional SPE (FB‐SPE) that covalently tethers fluorinated chains with polyether‐based segments is proposed and synthesized via photo‐controlled radical polymerization (photo‐CRP). In contrast to the conventional non‐fluorinated polyether‐derived SPEs, FB‐SPE is able to provide conducting Li+ transport pathways up to ≈5.0 V, while simultaneously forming a LiF interaction that can enhance Li anode compatibility and prevent Li dendrites growth. As a result, the FB‐SPE exhibits outstanding cycling stability in Li||Li symmetrical cells of over 1500 operating hours at as high current density as 0.2 mA cm−2. A thin and uniform Li deposition layer and LiF‐rich SEI at the surface of Li anode are found, and stable cycling with average coulombic efficiencies of 99% is demonstrated in Li||LFP and Li||NCM all‐solid‐state batteries based on such bifunctional fluorinated SPEs. The interesting fluorine effect and effective self‐suppression of lithium dendrites will inform rational molecular design of novel electrolytes and practical development of all‐solid‐state Li metal batteries. [ABSTRACT FROM AUTHOR]

This study investigates the top‐of‐atmosphere (TOA) radiation budget (RT) and cloud radiative effects (CREs) over the Tibetan Plateau (TP) and adjacent Asian monsoon regions including Eastern China (EC) and South Asia (SA) using the Coupled Model Intercomparison Project 6 (CMIP6) simulations. Considerable simulation biases occur but specific causes differ in these regions. Most models underestimate the intensity of annual mean RT and cloud radiative cooling effect over the TP, and the RT during the cold‐warm transition period is hard to capture. The biases in surface temperature and cloud fractions substantially contribute to cloud‐radiation biases over the western and eastern TP, respectively. Over EC, the intensity of RT and cloud radiative cooling effect is seriously underestimated especially in the springtime when the model spread is large, and their biases are closely related to less low‐middle cloud fractions and weaker ascending motion. Over SA, simulation biases mainly arise from longwave radiative components associated with less high cloud fraction and weaker convection, with the large model spread in the summertime. The annual cycles of RT and CREs over EC and SA can be well reproduced by most models, while the summertime peak of the net CRE over the TP occurs later than the observation. The RT and its simulation bias strongly depend on the cloud radiative cooling effect over EC and SA. Our results demonstrate that contemporary climate models still have obvious difficulties in representing various complex cloud‐radiation processes in Asian monsoon regions. Key Points: Radiation budget (RT) and cloud radiative cooling effect are underestimated over the Tibetan Plateau (TP) and Eastern China (EC), but cloud radiative cooling effect is overestimated over South Asia (SA)The simulated cloud‐radiation biases are related to less low‐middle clouds and weaker ascending motion over EC, less high clouds and weaker convection over SA, and lower surface temperature over the western TPMost models can capture the high dependence of RT on cloud radiative cooling effect over EC and SA, but fail to reproduce it over the TP [ABSTRACT FROM AUTHOR]

Understanding the source of atmospheric aerosol is an essential step in determining the aerosol radiative effect over the Tibetan Plateau (TP). This study aims to clarify the contributions of anthropogenic and natural emission to the aerosols (carbonaceous and sulphate) characteristics inside the TP. An aerosol model named Spectral Radiation Transport Model for Aerosol Species (SPRINTARS) recently coupled to the climate model named Chinese Academy of Sciences Flexible Global Ocean Atmosphere Land System (CAS‐FGOALS‐f3‐L) is used to simulate meteorological conditions and aerosols from 1985 to 2013, given emissions from the sixth phase of the Coupled Models Intercomparison Project (CMIP6). Comparisons between the simulations and ERA5 reanalysis data present that the model can capture the key spatial and temporal features of meteorological elements (2‐m temperature, relative humidity, and wind field at 500 hPa) over the Asia. Subsequently, we conduct six sensitivity studies to quantify the contributions of sources to aerosol surface concentration, burden and aerosol optical depth (AOD) over the TP. Our results illustrate that the outside and local anthropogenic sources contribute about 75.2% (78.9% in summer and 66.6% in winter) and 13.5% (7.4% in summer and 24.0% in winter) to the annual mean aerosols surface concentrations over the TP. The outside anthropogenic sources contribute to AODs in TP up to 87.3% (93.9% in autumn and 80.6% in winter). The ascending air over the TP is conducive to the transportation of the outsource pollutions to the TP. The outside natural sources (refer to biomass burning sources) contribute about 10% to aerosols over TP, and the inside natural sources play minor roles. The black carbon, organic carbon and sulphate (BOCS) induce average radiative forcing of −0.7 W m−2 at the near surface over the TP. [ABSTRACT FROM AUTHOR]

Several laboratory experiments using scanning electron microscopy and mercury intrusion porosimetry were conducted to study the development of soil microstructure during electroosmosis dewatering process. The test results indicate that the moisture content in different treating areas shows remarkable temporal difference; the reasons could be attributed to the distance to the drainage outlets and the treatment duration. On a microscopic level, the affected pore sizes are mainly 0.01–1 and 1–10 μm, and their proportions start to vary when the moisture content reaches the liquid limit. The total volume for pores in anodic soil decreases nearly 50% after the first 20% of total drainage water is exported and is not linearly related to the amount of discharged water. The surface of the soils becomes smoother, and clay particle connection changes from edge-to-edge to face-to-face. Pores are hard to be observed at the end of the process. [ABSTRACT FROM AUTHOR]

Breast cancer, one of the most frequently diagnosed and aggressive malignancies, is the major cause of cancer‐related death greatly threatening women health. Polypeptide N‐acetylgalactosaminyltransferase 4 (ppGalNAc‐T4), responsible for the initial step of mucin‐type O‐glycosylation, has been reported to be implicated in diverse types of human tumors. However, the biological role of ppGalNAc‐T4 in breast cancer is still undetermined. In this study, we investigate the effects and mechanism of ppGalNAc‐T4 to breast cancer cell proliferation. From analysis of high throughput RNA sequencing datasets of Gene Expression Omnibus and ArrayExpress, a positive correlation between ppGalNAc‐T4 and the recurrence‐free survival was observed in multigroup of human breast cancer datasets. Moreover, transcriptomes analysis using RNA‐sequencing in MCF7 cells revealed that cell cycle‐related genes induced the effects of ppGalNAc‐T4 on breast cancer cell proliferation. Additionally, investigations showed that ppGalNAc‐T4 impaired cell proliferation in MCF‐7 and MDA‐MB‐231 breast cells. Furthermore, our results suggested that the ppGalNAc‐T4 knockout activated Notch signaling pathway and enhanced cell proliferation. Collectively, our data indicated that ppGalNAc‐T4 affected the proliferation of human breast cancer cells, which appears to be a novel target for understanding the underlying molecular mechanism of breast cancer. [ABSTRACT FROM AUTHOR]

The variability of interior atmospheric potential vorticity (PV) is linked with PV generation at the Earth's surface. The present paper reveals the features of the surface PV and provides a stepping stone to investigate the surface PV budget. In this study, the formats of the PV and PV budget adopting a generalized vertical coordinate were theoretically examined to facilitate the calculation of the surface PV and its budget. Results show that the formats of the PV and PV budget equations are independent of the vertical coordinate. While the vertical component of the surface PV dominates over the platform of the Tibetan Plateau, the horizontal component plays an important role over the slopes of the Tibetan Plateau, especially the southern slope owing to the strong in‐situ meridional gradient of the potential temperature. These results indicate that the employment of complete surface PV not only provides a finer PV structure but also more appropriately reveals its effect on atmospheric circulation. Diagnosis based on reanalysis and model output demonstrates that the surface PV budget equation is well balanced both in terms of the climate mean and synoptic process, and the surface PV budget in June has a prominent diurnal cycle. The diabatic heating with a minimum in the early morning and a maximum from evening to midnight contributes dominantly to this diurnal cycle. It is further indicated that positive PV generation due to diabatic heating is essential for the formation, development, and movement of the Tibetan Plateau vortex. [ABSTRACT FROM AUTHOR]

Block‐sparse signals, whose non‐zero entries appear in clusters, have received much attention recently. An unfolded network, named Ada‐BlockLISTA, was proposed to recover a block‐sparse signal at a small computational cost, which learns an individual weight matrix for each block. However, as the number of network parameters is increasingly associated with the number of blocks, the demand for parameter reduction becomes very significant, especially for large‐scale multidimensional harmonic retrieval (MHR) problems. Based on the dictionary characteristics in two‐dimensional (2D) harmonic retrieve problems, the authors introduce a weight coupling structure to shrink Ada‐BlockLISTA, which significantly reduces the number of weights without performance degradation. In simulations, the proposed block‐sparse reconstruction network, named AdaBLISTA‐CP, shows excellent recovery performance with a smaller number of learned parameters. [ABSTRACT FROM AUTHOR]

We implement an existing aerosol module named Spectral Radiation Transport Model for Aerosol Species (SPRINTARS) in the Chinese Academy of Sciences Flexible Global Ocean–Atmosphere–Land System (CAS‐FGOALS) model and simulate the global aerosol properties over 2002–2014. The simulated surface mass concentrations of individual aerosols generally reproduce the observed ones. The simulated spatial‐temporal distributions of the aerosol optical depths (AODs) are evaluated with multisource satellite retrievals, and the simulated AOD, Ångström Exponent (AE), and single scattering albedo (SSA) are further evaluated with the ground‐based Aerosol Robotic Network (AERONET) measurements. The spatial distribution of the modeled AOD is found to be generally comparable to the satellite retrievals. The interannual and seasonal variations of the modeled AOD over various aerosol regimes are also overall consistent with the AERONET observations. With respect to the AE, our model can reproduce the interannual variations fairly well over the dust dominant regions, and generally capture the seasonal variations over the industrial domain regions. Over the industrial domain regions, however, the systematic underestimation of the simulated AE is found, which is in part due to the biases of wind fields and overestimation of the relative humidity (RH) by the host model. With respect to the SSA, our model can also generally reproduce the observed seasonal variations, while the modeled values are typically lower than the observations, especially over North Africa. Key Points: The interannual and seasonal variation of modeled aerosol optical properties are overall consistent with the observations at most regionsBiases of the meteorological fields are responsible for underestimation of the Ångström Exponent over the industrial dominant regionsThe seasonal variations of aerosol optical depth in the dust dominant region can be better reproduced with more realistic wind fields [ABSTRACT FROM AUTHOR]

Resistance to radiotherapy is frequently encountered in clinic, leading to poor prognosis of cancer patients. Long noncoding RNAs (lncRNAs) play important roles in the development of radioresistance due to their functions in regulating the expression of target genes at both transcriptional and posttranscriptional levels. Exploring key lncRNAs and elucidating the mechanisms contributing to radioresistance are crucial for the development of effective strategies to reverse radioresistance, which however remains challenging. Here, actin filament‐associated protein 1 antisense RNA1 (lncAFAP1‐AS1) is identified as a key factor in inducing radioresistance of triple‐negative breast cancer (TNBC) via activating the Wnt/β‐catenin signaling pathway. Considering the generation of a high concentration of reduction agent glutathione (GSH) under radiation, a reduction‐responsive nanoparticle (NP) platform is engineered for effective lncAFAP1‐AS1 siRNA (siAFAP1‐AS1) delivery. Systemic delivery of siAFAP1‐AS1 with the reduction‐responsive NPs can synergistically reverse radioresistance by silencing lncAFAP1‐AS1 expression and scavenging intracellular GSH, leading to a dramatically enhanced radiotherapy effect in both xenograft and metastatic TNBC tumor models. The findings indicate that lncAFAP1‐AS1 can be used to predict the outcome of TNBC radiotherapy and combination of systemic siAFAP1‐AS1 delivery with radiotherapy can be applied for the treatment of recurrent TNBC patients. [ABSTRACT FROM AUTHOR]

This study reviews the development of the omega equation and the relation between omega and potential vorticity (PV) advection and considers the application of PV theory to investigate the impact of large‐scale mountains on downstream weather development. A diabatic quasi‐geostrophic omega equation is introduced to reveal the feedback of diabatic heating (Q) on PV advection and vertical velocity. A challenge therein concerning the use of the diagnostic omega equation to interpret weather system development is considered from the PV‐Q perspective based on a severe weather event that occurred downstream of the Tibetan Plateau (TP) on 17–21 January 2008. Results demonstrate that owing to PV restructuring, positive PV was generated over the eastern flank of the TP, and its eastward advection triggered development of isentropic displacement vertical velocity and cyclogenesis in the lower troposphere. A converging southeasterly wind accompanied with ascending isentropic gliding vertical velocity in the lower troposphere was induced to the east of the cyclone center, which transported not only warm moist air but also negative PV from the south, contributing to developments of both local diabatic ascent and precipitation and eastward migration of the cyclone. During the cyclone life cycle, three omega components induced by different processes interacted with each other, and diabatic heating associated with precipitation exerted considerable feedback to vertical motion as well as PV advection. It is the vertical differential PV advection and feedback from diabatic heating that control the evolution of the circulation and the associated precipitation downstream of the TP. Plain Language Summary: Based on a brief review of the development of vertical velocity equation, a modified equation for the vertical velocity that is associated with the development of thermal field is deduced to link with condensation heating and horizontal transport/advection of potential vorticity (PV, a quantity measuring the potential of vorticity development). It is applied to interpret the cyclogenesis and associated severe precipitation downstream of the Tibetan Plateau in a winter case study. Results demonstrate that the cyclogenesis is strongly tied both to the PV generation near the surface of the eastern Tibetan Plateau and to its subsequent downstream eastward advection. The latter triggers the development and interaction of various vertical velocity components, air convergence, and cyclogenesis in the lower troposphere, leading to precipitation and condensation heating. The life cycle of cyclogenesis is controlled by the vertical coupling between the zonal positive PV advection in the midtroposphere and the meridional negative PV advection in the lower troposphere. The heating in return can influence PV advection and vertical velocity development. It is the vertical variation of horizontal PV advection and interaction with condensation heating that control the development of vertical velocity, the evolution of cyclogenesis, and the associated precipitation downstream of the Tibetan Plateau. Key Points: Development of the omega equation is reviewedImpact of large‐scale mountains on downstream cyclogenesis is considered from the perspective of potential vorticity and diabatic heatingFeedback of diabatic heating on vertical velocity and potential vorticity advection during the cyclone life cycle is investigated [ABSTRACT FROM AUTHOR]

One of the heaviest precipitations over the Asian continent in winter is located in the western Tibetan Plateau (TP). In this study, the dynamics of the precipitation over the western TP (PWTP) in boreal winter and its interannual variability are explored. The moisture origins and paths are detected using a Lagrangian Integrated Trajectory model. In climatology, the PWTP is generated as results of upward air motions on the windward side of the TP and ranges from 0.5 to 2.5 mm·day−1. Under the influence of midlatitude westerlies and the subtropical high over the Arabian Peninsula, three key moisture sources (by percentage contribution) are identified: South Asia‐North Indian Ocean (56.6%), Central Eurasia‐North Africa (37.7%), and Central‐North Atlantic (5.6%). The dominant precipitating cloud types are nimbostratus and stratus/stratocumulus derived from satellite data. On the interannual timescale, PWTP variation is closely associated with El Niño‐Southern Oscillation (ENSO) and midlatitude cyclones. ENSO warm events lead to an anomalous anticyclone over the tropical northwest Indian Ocean and intensify moisture transport northward in the lower troposphere, as well as abnormal divergence in upper troposphere. However, ENSO explains only about 38.1% of the PWTP variance. Midlatitude teleconnection also contributes to the PWTP variability, which is comparable to the effect of ENSO. The cyclones imbedded in the subtropical jet are part of the teleconnection, with an anticyclone upstream over the North Atlantic and an cyclone over the western TP. Further evidence suggests that the transient eddies in the North Atlantic help to maintain the teleconnection. Key Points: Moisture origins and dominant precipitating clouds for winter precipitation over western Tibetan Plateau are identifiedENSO plays a key role in winter precipitation interannual variability by modulating upper‐level divergence and low‐level moisture transportMidlatitude teleconnection, mainly maintained by transient eddies, influences the precipitation variability, comparable to that of ENSO [ABSTRACT FROM AUTHOR]

Synthesising radar and communication waveforms in different directions using a common array is a hardware-saving solution for the coexistence of communication and radar in competitive spectrum environments. Here, the authors establish the problem of designing array probing signal to maximise power of the synthesised communication and radar waveforms, given array transmitting power, under no-waveform-error constraint and unit-modular-array-probing-signal constraint. Alternating direction method of multipliers (ADMM) is used to solve this problem. The results of numerical experiments show that, by solving this problem with ADMM, error of the synthesised waveforms can be completely eliminated, and the power of synthesised waveforms is almost optimal. [ABSTRACT FROM AUTHOR]

We evaluate the ability of the latest generation atmospheric general circulation model from State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (namely, FAMIL2) in simulating some key characteristics (genesis location, track, number, and intensity) of tropical cyclones (TCs) in terms of their climatology and seasonal to interannual variability. A standard 1° × 1° atmospheric model intercomparison project experiment is carried out for the period 1979–2002, and the last 20 years of outputs are used for analysis. The same period from International Best Track Archive for Climate Stewardship (IBTrACS) is used as the observation for comparison purposes. The evaluations focus on TC activity at the global scale as well as in the three key regions of the northern Indian Ocean (NIO), western Pacific (WP) and northern Atlantic (NA). With respect to the simulated TC climatology, FAMIL2 shows notable ability in correctly reproducing the main characteristics of the genesis locations, tracks, and numbers of TC, particularly over the key regions of TC activity in the Northern Hemisphere; whereas, it underestimates the intensities of TC, as is the case with many state‐of‐the‐art climate models operating at a medium resolution. On seasonal‐to‐interannual time scales, meanwhile, FAMIL2 successfully reproduces the seasonal cycles of TC numbers over the NIO and WP regions, the former being characterized by double TC peaks (in May and October) and the latter by a maximum peak season in August. However, the model only captures these features approximately. For the simulated interannual variability of TC activity, the correlation coefficients of 20‐year TC numbers between FAMIL2 and IBTrACS are 0.22, 0.51 (95% confidence interval), and 0.49 (95% confidence interval) for the NIO, WP, and NA, respectively. We also examine the possible reasons behind the performance of FAMIL2 by investigating its subseasonal signs related to the Madden‐Julian Oscillation (MJO) and convectively coupled equatorial waves. The TC genesis potential index is employed to investigate the possible impacts of the large‐scale dynamic fields on the simulation of TC activity. Finally, the biases of simulated TC activity, as well as possible solutions for these biases, are discussed with respect to the horizontal resolution of the model. A TC forecasting case study is introduced as a first step in applying FAMIL2 to a TC forecasting system. Key Points: Characteristics of global and regional tropical cyclone are simulated in FAMIL2We identify potential reasons to tropical cyclone activity in FAMIL2We discuss the impacts of spatial resolution and introduce the application development of tropical cyclone prediction [ABSTRACT FROM AUTHOR]

As a typical signal processing problem, direction-of-arrival (DOA) estimation has been adapted to a wide range of applications in radar-based systems. A high DOA resolution requires a large number of antenna elements which increases the overall cost. To minimise the cost, it is desirable to choose an optimum sub-array from a full array. To enable cognition, the subarrays are selected based on the present target scenario. By using deep learning (DL) based techniques, the authors show a cognitive sparse array selection technique. By using hardware simulations, they demonstrate the applicability of the deep learning (DL)-based sparse antenna selection network in direction-of-arrival (DOA) estimation problems. They show that the DL-based sub-arrays lead to a higher direction-of-arrival (DOA) estimation accuracy by 6 dB over random array selection. [ABSTRACT FROM AUTHOR]

Abstract: The intraseasonal variation of the Tibetan Plateau summer monsoon (TPSM) during 1979–2011 is investigated. The TPSM shows a dominant quasi‐biweekly oscillation (QBWO) in most summer seasons, and its active/break phases are closely related to more/less precipitation over the Tibetan Plateau. We suggest that the TPSM QBWO is associated with a southeastward propagating nonstationary wave train in the middle and upper troposphere. It shows equivalent barotropic vertical structures over the midlatitudes and a baroclinic structure over the eastern Tibetan Plateau. Wave activity flux analysis indicates that it originates from northern Europe, which is an active center of the summertime Arctic Oscillation (AO). The AO also shows significant QBWO signals and leads TPSM QBWO by about 13 days. Phase composite and wave activity flux analyses of AO QBWO confirmed that the wave train influences TPSM QBWO, suggesting that AO plays an important role in the TPSM on a 10‐ to 20‐day timescale. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy. Long non-coding RNAs (lncRNAs) are important regulators in pathological processes, yet their potential roles in PDAC are poorly understood. Here, we identify a fundamental role for a novel lincRNA, linc00511, in the progression of PDAC. Linc00511 levels in PDAC tissue specimens and cell lines were examined by quantitative real-time PCR. Corresponding adjacent non-neoplastic tissues were used as controls. The function of linc00511 in PDAC cell lines was determined by RNA interference approach in vitro and in vivo. Fluorescence in situ hybridization (FISH) was used to characterize linc00511 expression in PDAC cells. Insights of the mechanism of competitive endogenous RNAs (ceRNAs) were obtained from bioinformatic analysis, luciferase assays and RIP assays. The association between the linc00511/hsa-miR29b-3p axis and VEGFA was verified by Western blotting assay. Immunohistochemistry was performed to evaluate the expression of VEGFA in PDAC samples. The aberrant up-regulation of linc00511 was detected in PDAC cell lines and patient specimens compared with controls. An increase in linc00511 expression indicates the adverse clinical pathological characteristics and poor prognosis. Functionally, linc00511 depletion in PDAC cells decreased proliferation, migration, invasion and endothelial tube formation. Mechanistically, linc00511 could up-regulate VEGFA via its competing endogenous RNA (ceRNA) activity on hsa-miR-29b-3p. In summary, our results define an important axis controlling proliferation, invasion and tumour angiogenesis in PDAC. Linc00511 is a novel lncRNA that plays a significant regulatory role in the pathogenesis and progression of PDAC. Thus, Linc00511 represents a new prognostic biomarker to predict clinical outcome of PDAC patients after surgery and may serve as a potential therapeutic target for PDAC treatment. [ABSTRACT FROM AUTHOR]

The oxidative stress caused by endothelial injury is involved in intimal hyperplasia ( IH) in vein grafts. Mesenchymal stem cells ( MSCs) can home to injured intima and promote endothelial repair. However, MSC apoptosis is increased accompanied by decreased functional activity under oxidative stress. Thus, we investigate whether tumour necrosis factor-α ( TNF-α) can promote the survival and activity of MSCs under oxidative stress to reduce IH more effectively, and establish what role the NF-κB pathway plays in this. In this study, we preconditioned MSCs with TNF-α ( TNF-α-PCMSCs) for 24 hrs and measured the activation of the IKK/ NF-κB pathway. EdU and transwell assays were performed to assess proliferation and migration of TNF-α-PCMSCs. Apoptosis and migration of TNF-α- PCMSCs were evaluated in conditions of oxidative stress by analysis of the expression of Bcl-2 and CXCR4 proteins. TNF-α- PCMSCs were transplanted into a vein graft model, so that cell homing could be tracked, and endothelial apoptosis and IH of vein grafts were measured. The results demonstrated that TNF-α promotes proliferation and migration of MSCs. Furthermore, survival and migration of TNF-α- PCMSCs under oxidative stress were both enhanced. A greater number of MSCs migrated to the intima of vein grafts after preconditioning with TNF-α, and the formation of neointima was significantly reduced. These effects could be partially abolished by IKK XII ( NF-κB inhibitor). All these results indicate that preconditioning with TNF-α can promote survival and migration of MSCs under oxidative stress via the NF-κB pathway and thus attenuate IH of vein grafts. [ABSTRACT FROM AUTHOR]

A new sensible-heat ( SH) parameterization was used in the Weather Research and Forecasting model to improve the vertical heat transfer simulation in arid regions. With this new scheme, the simulated SH decreased, resulting in a 2 °C reduction of the cold bias in the land surface temperature over the Tibetan Plateau. The weakened SH led to anticyclonic circulation and cyclonical flow changes in the northern East China due to Rossby wave propagation. The summer-rainfall in East Asian is marginally improved. It is suggested that the SH simulation over the Plateau is a land-atmosphere coupling issue that is important to the dynamical downscaling in East Asian. [ABSTRACT FROM AUTHOR]

The automobile market in China has seen unprecedented expansion during the past decade with rapid model turnover and dramatic price decline. This paper aims to document the evolution of price and investigate the sources of price decline, paying attention to both market structure and cost factors. We estimate a market equilibrium model with differentiated multiproduct oligopoly using market-level sales data in China together with information from household surveys. Our counterfactual simulations show that (quality-adjusted) vehicle prices have dropped by 33% from 2004 to 2009. The decrease in markup from intensified competition accounts for about one third of this change and the rest comes from cost reductions through learning by doing and other channels. In addition, our simulations show that the price decline would have been larger had it not been for the growth of household income during this period. [ABSTRACT FROM AUTHOR]