China launched its first spaceborne Precipitation Measurement Radar(PMR)on the FY-3G satellite in April 2023.To achieve the scientific goal of measuring the three-dimensional precipitation structure,evaluating the qua...China launched its first spaceborne Precipitation Measurement Radar(PMR)on the FY-3G satellite in April 2023.To achieve the scientific goal of measuring the three-dimensional precipitation structure,evaluating the quantitative measurement ability of the PMR is critical.China operates more than 250 weather radars over the mainland.Consistency of the spaceborne radar with ground-based radars will enhance precipitation measurement ability,especially over oceans and mountains where observations are sparse.Additionally,the spaceborne radar can be used to evaluate the spatial and temporal homogeneity of the ground-based radar network.This paper focuses on comparing the PMR onboard the FY-3G satellite with S-band China New Generation Weather Radars(CINRADs).A comparison algorithm between the PMR and CINRADs has been developed,incorporating detailed quality control,attenuation correction,data optimization,spatiotemporal matching,non-uniform beam filling constraint,uniformity constraint,and frequency correction.The matched data in typical months of four seasons were selected to carry out the comparison.The data consistency between the PMR and CINRADs was analyzed.The correlation coefficient is 0.87,the deviation is 0.89 dB,and the standard deviation is 2.50 dB,based on 98226 matching samples.The results show the radar reflectivity of the PMR is quite comparable to that of the CINRADs,demonstrating that the PMR data quality is satisfactory and can be used to verify and correct data consistency among multiple ground-based radars.This work also paves the way for data fusion and joint application of satellite and ground radars in the future.展开更多
Based on conventional meteorological observation data,radar data and numerical forecast product data,the causes of the first large-scale,high-intensity and long-duration rainstorm in Dehong Prefecture during May 11-16...Based on conventional meteorological observation data,radar data and numerical forecast product data,the causes of the first large-scale,high-intensity and long-duration rainstorm in Dehong Prefecture during May 11-16,2022 were analyzed by using the weather dynamic diagnosis and analysis method.The results show that the rainstorm process was caused by strong uplift and condensation in the west and north of Yingjiang under the background of dry and cold northwest air circulation at 500 hPa,the absence of obvious influence of the south branch trough at 700 hPa,and strong southwest jet at 850 hPa.The southwest jet in the boundary layer provided sufficient warm water vapor,unstable energy and uplifting conditions for the rainstorm.Low-level convergence,high-level divergence and strong upward movement in the whole layer were conducive to the uplift and condensation of a large number of warm and humid air in the northwest of Yingjiang in Dehong Prefecture,which enhanced the development of mesoscale convective system(MCS)and prolonged the life history ofβmesoscale convective system.The application of satellite,radar and other mesoscale data has an important reference value for the tracking,correction,forecast and early warning of the rainstorm process.展开更多
It is not only meteorological problems for the medium-range numerical weather prediction (NWP) research to be in operation,but also engineering and technological problems.Here we gener- ally described the results of r...It is not only meteorological problems for the medium-range numerical weather prediction (NWP) research to be in operation,but also engineering and technological problems.Here we gener- ally described the results of research,engineering construction,operation information and testing,in the course of set-up of medium-range NWP operation system in the China National Meteorological Center.展开更多
The“Outline for High-Quality Development of Meteorology(2022-2035)”was published by the State Council of the People’s Republic of China in April 2022(1).This publication highlights the essential role of meteorologi...The“Outline for High-Quality Development of Meteorology(2022-2035)”was published by the State Council of the People’s Republic of China in April 2022(1).This publication highlights the essential role of meteorological disaster warnings,particularly cold spell warnings,in preventing and mitigating disasters.The outline also sets forth stricter expectations for enhancing the overall capacity of society in terms of meteorological disaster preparedness and response.展开更多
Based on the number of asthmatic children in the Children's Hospital of Yulin City,the monitoring data of daily pollen concentration,and routine meteorological and environmental monitoring data of Yulin City from ...Based on the number of asthmatic children in the Children's Hospital of Yulin City,the monitoring data of daily pollen concentration,and routine meteorological and environmental monitoring data of Yulin City from 2020 to 2022,the meteorological and environmental conditions of a thunderstorm asthma event in Yulin City in northern Shaanxi on September 9,2022 were analyzed.The results show that the strong convective weather was accompanied by a strong thunderstorm,lightning,gusts,short-time heavy precipitation and small hail,and the convective activity lasted for nearly 7 h.The short-term abrupt change of allergenic substances such as artemisia pollen caused by lightning,gusts and precipitation,the sudden drop in temperature,the inversion near the surface and the stimulation of cold air were the key meteorological conditions for the subsequent outbreak of asthma.In early September in 2022,the daily average pollen concentration in Yulin City was up to 1067.9 particles/1000 mm^(2),which was 113.3%and 41.2%higher than that of the same period in 2021 and 2020,respectively.The day before the thunderstorm,the pollen concentration soared to 2680 particles/1000 mm^(2),reaching the maximum of the year.The synergistic effect of the thunderstorm event and the sharp increase in pollen concentration on the previous day provided the background of heavy pollen pollution for this outbreak of thunderstorm asthma.O_(3)concentration was consistently high on the day of thunderstorm and the day before,and the peaks of O_(3)and PM 10 concentration appeared subsequently in the afternoon of the day,which became the background of air pollution for the asthma outbreak.展开更多
This study investigated the quasi-biweekly oscillation(QBWO)of the South Asian high(SAH)center in midsummer and its possible impact on rainfall in the middle and lower reaches of the Yangtze River Basin(MLYRB),using E...This study investigated the quasi-biweekly oscillation(QBWO)of the South Asian high(SAH)center in midsummer and its possible impact on rainfall in the middle and lower reaches of the Yangtze River Basin(MLYRB),using ERA5 reanalysis data and CPC(Climate Prediction Center)Global Unified Precipitation data from 1979-2023.First,associated with the phase evolution of the QBWO of the SAH center zonally,a general systematic westward propagation of a wave train pattern along the northern margin of the SAH can be identified.Second,energy analysis indicates that this wave train pattern gains energy from the basic flow through both barotropic and baroclinic energy conversion.Compared with barotropic energy conversion,baroclinic energy conversion plays the more important role in the growth,maintenance,and propagation of the wave train pattern associated with the QBWO of the SAH center.Third,the QBWO of the SAH center leads the variation in rainfall in the MLYRB by approximately four days,and might modulate the precipitation in the MLYRB by affecting the coupling of upper-and lower-level circulation anomalies over the MLYRB.The findings of this study suggest that the QBWO of the SAH center could act as potential source of predictability of intraseasonal variation in precipitation in the MLYRB.展开更多
FY-3G is the first polar-orbiting satellite equipped with a precipitation measurement radar(PMR)operating at Ku-andKa-band frequencies in China.In this study,we compare the reflectivity data from the FY-3G PMR Ku prod...FY-3G is the first polar-orbiting satellite equipped with a precipitation measurement radar(PMR)operating at Ku-andKa-band frequencies in China.In this study,we compare the reflectivity data from the FY-3G PMR Ku product and groundbasedradars(GRs)during 2024.Also,the FY-3G PMR is used as a third-party reference to evaluate the reflectivityconsistency among different GRs.The FY-3G PMR and GRs share similarities in their general distribution,characteristics,and intensity of reflectivity in strong precipitation cloud systems,though the former presents less detailed system structure.Systematic deviations between the FY-3G PMR and GRs and between GRs are comparable,albeit the reflectivity of the FY-3G PMR is generally slightly stronger than that of GRs(especially X-band GRs),with a mean bias ranging from 0.7 to 1.7dB.S-band GRs exhibit the smallest systematic deviation(STD=3.09 dB)from the FY-3G PMR,whereas the X-band GRsshow the largest(STD=3.61 dB),indirectly indicating the highest internal consistency among S-band GRs and the lowestamong X-band GRs.Besides,both S-and C-band GRs display similar deviations when paired with the FY-3G PMR as wellas when paired with their adjacent S/C-band GRs,suggesting good consistency between these two bands.In contrast,XbandGRs exhibit relatively poor consistency with S-band GRs and the FY-3G PMR,showing a deviation ranging from 3.0to 4.6 dB.展开更多
In massive multiple-input multiple-output(MIMO)systems utilizing frequency division duplexing,optimizing system performance requires user equipment(UE)to compress downlink channel state information(CSI)and transmit it...In massive multiple-input multiple-output(MIMO)systems utilizing frequency division duplexing,optimizing system performance requires user equipment(UE)to compress downlink channel state information(CSI)and transmit it to the base station(BS).As the number of antennas increases,there is a significant rise in the overhead related to CSI feedback,posing considerable challenges to the precise acquisition of CSI by the BS.Existing approaches to CSI feedback utilizing deep learning techniques face challenges such as significant feedback overhead and limited precision in the reconstruction process.This study presents a novel lightweight CSI feedback framework known as the dual attention neural network(DANet).Within the DANet architecture,a dual attention module(DAM)is designed to enhance the network's performance.This DAM includes both channel attention blocks and spatial attention blocks.The channel attention blocks direct the model's focus toward channel features rich in information content while simultaneously suppressing less significant features.This approach enables the extraction of temporal correlations within the CSI matrix.The spatial attention block aids in extracting the correlation between the delay domain and the angle domain in the CSI matrix.By enhancing neural network performance,the DAM reduces information dispersion while enhancing the representation of global interactions.Simulation results demonstrate that DANet exhibits superior normalized mean square error and cosine similarity with comparable complexity compared to existing advanced CSI feedback methods.展开更多
The Triple Ionosphere Photometer(TRIPM)is a scientific payload aboard the Fengyun-3E(FY-3E)satellite,which operates in a dawn−dusk orbit.It is primarily designed for nadir observations of airglow emissions at OI 135.6...The Triple Ionosphere Photometer(TRIPM)is a scientific payload aboard the Fengyun-3E(FY-3E)satellite,which operates in a dawn−dusk orbit.It is primarily designed for nadir observations of airglow emissions at OI 135.6 nm and N_(2)Lyman-Birge-Hopfield(LBH)bands.Due to the satellite’s dawn−dusk orbital characteristics,most of TRIPM’s field of view remains in a semi-illuminated condition.Therefore,compared with airglow data of the same bands acquired under purely daytime or nighttime conditions,applying TRIPM data poses greater challenges.This study presents the first attempt to use TRIPM data for retrieving solar extreme ultraviolet(EUV)flux.Our results demonstrate that by utilizing TRIPM data in regions where photoelectron excitation dominates as the primary radiation source,the solar EUV flux(denoted as Q_(EUV))can be retrieved.Comparisons with data from the SOHO/SEM instrument reveal excellent consistency,with a seasonal correlation coefficient(R)of at least 0.95.This work thus offers a new avenue for solar EUV flux acquisition and expands the application range of TRIPM data.展开更多
Low-visibility phenomena strongly impact the environment,as well as transportation,aviation and other fields that are closely related to people's livelihoods;thus,they represent important ecological issues of soci...Low-visibility phenomena strongly impact the environment,as well as transportation,aviation and other fields that are closely related to people's livelihoods;thus,they represent important ecological issues of social concern.Based on observation data concerning low-visibility phenomena derived from 105 national meteorological stations in Xinjiang,China over the past 20 years,we systematically analyzed the differences between manual and instrument observations for six types of low-visibility phenomena,with a focus on exploring their spatiotemporal distribution characteristics using instrument data.The results revealed that low-visibility phenomena were dominated by fog-and haze-related events(mist,fog,and haze)in northern Xinjiang and dust-related events(dust storms,blowing sand,and floating dust)in southern Xinjiang,with transitional characteristics observed in eastern Xinjiang.Compared with manual observations,the instrument measurements significantly improved the fine-scale low-visibility phenomenon identification process.On the basis of the instrument observation data,spatial-dimension analysis results indicated that low-visibility phenomena in Xinjiang were significantly influenced by terrain factors.Constrained by the Tianshan Mountains,haze-like phenomena formed a core agglomeration area in northern Xinjiang,whereas dust-and sand-related phenomena radiated outward,with the Taklimakan Desert at the center.Moreover,the gripping effect of the terrain promoted dust transmission along low-altitude channels.Temporally,fog-and haze-related phenomena occurred mainly during autumn and winter,and the proportion of these events decreased from 76.7%to 55.1%.The fog-and haze-related phenomena demonstrated a U-shaped rebound trend,while the proportion of mist phenomena decreased by 34.2%.Dust storms occurred during spring,accounting for 23.3%to 44.9%of all storms.Instrument measurement technology has the advantages of high spatial and temporal resolutions and multiparameter coordination but provides a limited dust-haze mixed-pollution identification capacity.This study provides crucial reference data for enhancing the understanding of low-visibility events in Xinjiang and the potential responses while improving the accuracy of pollution source tracking and meteorological process diagnosis tasks.展开更多
Ground-based radar is the primary means by which severe storms are monitored and tracked;however, due to limited coverage, important data is often missed over ocean and mountainous areas. On the other hand, geostation...Ground-based radar is the primary means by which severe storms are monitored and tracked;however, due to limited coverage, important data is often missed over ocean and mountainous areas. On the other hand, geostationary(GEO)weather satellites provide continuous observations with seamless coverage with advanced imager, despite their limited capability to penetrate clouds. Combining satellite and ground-radar observations could exploit the advantages of both techniques, providing tracking capability close to that of ground radar while maintaining full spatial coverage. This study presents a novel method called Multi-dimensional satellite Observation information for Radar Estimation(MORE) to reconstruct radar composite reflectivity(CREF). Deep learning techniques are important components of MORE for estimating CREF from China's Fengyun-4B(FY-4B) GEO satellite observations. Two models are developed: an infraredonly(IR-Single) model available for all times, and a visible-infrared(VIS+IR) model for daytime applications. These models incorporate multi-dimensional satellite observation information, including temporal, spatial, spectral, and viewing angle information, to enhance the accuracy of radar echo reconstruction. Results demonstrate that the VIS+IR model outperforms the IR-Single model, and both models achieves a root-mean-square error(RMSE) of less than 6 dBZ and a coefficient of determination(R~2) of greater than 0.7. The models effectively reconstruct radar echoes, including strong echoes exceeding 50 dBZ, and show good agreement with precipitation data in radar-blind areas. This study offers a valuable solution for severe weather monitoring and tracking in regions lacking ground-based radar observations, and provides a potential tool for enhanced data assimilation in numerical weather prediction(NWP) models.展开更多
The calculation of viewing and solar geometry angles is a critical first step in retrieving atmospheric and surface variables from geostationary satellite observations.Whereas the viewing angles for geostationary sate...The calculation of viewing and solar geometry angles is a critical first step in retrieving atmospheric and surface variables from geostationary satellite observations.Whereas the viewing angles for geostationary satellites are not timevarying,a primary source of inaccuracy in solar positioning is the use of a single timestamp.Since pixel scanning times can differ significantly across the field-of-view disk(e.g.,by approximately 13 min for Fengyun-4B),this practice leads to errors of up to±2°in solar zenith angle,which translates to±50 W m^(−2) in extraterrestrial irradiance;the errors in solar azimuth angle can exceed±100°.Beyond scanning time,this work also quantifies the impact of other inputs—including altitude,surface pressure,air temperature,difference between Terrestrial Time and Universal Time,and atmospheric refraction—on the resulting angles.A comparison of our precise calculations with the official National Satellite Meteorological Center L1_GEO product shows an accuracy within 0.1°,confirming its utility for most retrieval tasks.To facilitate higher precision when required,this work releases the corresponding satellite and solar positioning codes in both R and Python.展开更多
Accurate calibration of China's new generation ground-based polarimetric radar(GR) network is crucial yet challenging. Although application of the Dual-frequency Precipitation Radar(DPR) of the Global Precipitatio...Accurate calibration of China's new generation ground-based polarimetric radar(GR) network is crucial yet challenging. Although application of the Dual-frequency Precipitation Radar(DPR) of the Global Precipitation Measurement Core Observatory for GR assessment is well-established, current methodologies are inherently limited. Focusing on three GRs in the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)—strategically selected for their high overlapping coverage(>65%) and distinct from single GR or less dense coverage studies—this work introduces key refinements by integrating innovative enhancements into the volume-matching method(VMM), reflecting a systematic approach to mitigating potential error sources. Specifically, we integrate: 1) a novel frequency correction method that adapts to DPR-observed precipitation phase and type, replacing assumption-based polynomial fitting;and 2) a precise beam time-difference matching approach(accuracy < 1 s) to minimize temporal mismatch errors, which improves upon coarser time averaging methods. Furthermore, we developed statistically robust, optimized threshold criteria based on systematic sensitivity analyses using 11 quality control factors, including precipitation type, bright band effects, and attenuation correction limitations. These criteria establish an enhanced protocol designed to minimize errors arising from instrumental, frequency, and scanning differences. Application of this enhanced methodology to the GBA GRs(2021–2023) yielded a significantly improved matching accuracy(correlation coefficient, CC: 0.90–0.95;standard deviation,STD: 1.2–1.6 dB). A unique contribution of this work is the quantitative estimation of historical calibration errors and operational stability, which was achieved by linking VMM results with operational GR calibration and maintenance records. This analysis revealed decreasing STD trends and identified specific calibration-related events, such as an underestimation of approximately 2.43 dB for the Shenzhen radar following calibration in 2023. Consequently, the refined methodology provides a robust framework for ongoing GR network monitoring and offers a validated pathway for authenticating China's Fengyun-3G(FY-3G) satellite precipitation measurement radar(PMR) data.展开更多
Autumn rain in western China(ARWC)is a unique and significant precipitation phenomenon that occurs during the summer-to-winter transition of the atmospheric circulation.Using the fifth generation of global climate and...Autumn rain in western China(ARWC)is a unique and significant precipitation phenomenon that occurs during the summer-to-winter transition of the atmospheric circulation.Using the fifth generation of global climate and weather reanalysis data from the European Centre for Medium-Range Weather Forecasts and CN05.1 grid precipitation data,this study examined the anomalous characteristics and mechanisms of ARWC by combining the synergistic effect of the westerly jet and meridional wind.Over the past 60 years,ARWC has exhibited significant interdecadal and interannual variations,as well as a north-south seesaw pattern.The westerly jet index(meridional wind index)exhibited a negative(positive)correlation with precipitation in the northern autumn rain zone(NARZ),and a positive(negative)correlation with precipitation in the southern autumn rain zone(SARZ).The coupling of a weak meridional southerly wind with a southward westerly jet and a strong meridional southerly wind with a northward westerly jet are the two primary modes that synergistically influence the ARWC.These synergistic effects cause significant atmospheric changes throughout the troposphere.The contrasting circulation structure,temperature advection,vertical motion,and water vapor flux contributed to the opposite precipitation anomalies observed in the NARZ and SARZ.A new comprehensive index that reflects the coupled synergistic effect is proposed to characterize the anomalous changes in ARWC.This study improves the understanding of the anomalous characteristics and mechanisms of ARWC.展开更多
The commencement of the tropical Asian summer monsoon(TASM)in May is a crucial phase in its seasonal evolution,with critical implications for agriculture and water resources.Based on observational and reanalysis data,...The commencement of the tropical Asian summer monsoon(TASM)in May is a crucial phase in its seasonal evolution,with critical implications for agriculture and water resources.Based on observational and reanalysis data,this study finds that the relationship between El Nino-Southern Oscillation(ENSO)and monsoon commencement experiences a notable interdecadal strengthening after 1976/77.While the response of tropical tropospheric temperature to ENSO remains largely unchanged,ENSO induces a stronger Walker circulation,a more pronounced equatorial Rossby wave,and an intensified extratropical Rossby wave train after 1976/77.These enhanced atmospheric processes,which directly reinforce the ENSO-TASM commencement relationship,are likely driven by interdecadal shifts in the structure and variance of ENSO.Post-1976/77,ENSO displays increased variance and a more coherent structure,with more pronounced sea surface temperature anomalies in the western North Pacific and subtropical North Pacific.Given the limitations of observational data,a 1000-year piControl experiment further confirms the role of ENSO variance changes in strengthening its influence on monsoon commencement.Our findings underscore the critical influence of evolving ENSO characteristics on climate anomalies such as monsoon commencement,offering potential insights for short-term climate prediction.展开更多
Persistent severe rainfall(PSR)events,defined as regional-scale rainfall processes with daily precipitation no less than 50 mm for at least three consecutive days,frequently occur over South China(SC)and the middle-to...Persistent severe rainfall(PSR)events,defined as regional-scale rainfall processes with daily precipitation no less than 50 mm for at least three consecutive days,frequently occur over South China(SC)and the middle-to-lower Yangtze River Basin(MLYRB),with distinct dynamic mechanisms and moisture conditions in the two regions.Based on daily precipitation observations from China’s national meteorological stations and ERA5 reanalysis during 2012-21,this study investigates the spatiotemporal distribution of PSR events in SC and MLYRB and their associated three-dimensional circulation dynamics.The analysis integrates diagnostics of 200 hPa wave activity flux,perturbation streamfunction,500 hPa geopotential height,850 hPa wind fields,and integrated water vapor transport.Results show that PSR events in SC mainly occur during May-June,with rainfall centers over coastal and central Guangdong and Guangxi.In contrast,MLYRB events peak during June-July,with a banded rainfall pattern along the middle-to-lower Yangtze River.Dynamical diagnostics indicate that,in SC,sustained northwest-southeast propagation of 200 hPa disturbances,the southward shift of the 500 hPa trough,and steady subtropical high maintenance provide continuous dynamical support.Concurrently,strong and persistent 850 hPa southwesterlies and long-lasting moisture transport form favorable moisture conditions.In contrast,MLYRB events are marked by rapid phase transitions of 200 hPa streamfunction anomalies and northward-westward expansion of the 500 hPa subtropical high,triggering intense rainfall development.Simultaneously,abrupt enhancement of 850 hPa southwesterlies and rapid formation of a southwest moisture corridor ensure abundant and timely moisture supply,facilitating PSR onset.展开更多
In this paper,the latest progress,major achievements and future plans of Chinese meteorological satellites and the core data processing techniques are discussed.First,the latest three FengYun(FY)meteorological satelli...In this paper,the latest progress,major achievements and future plans of Chinese meteorological satellites and the core data processing techniques are discussed.First,the latest three FengYun(FY)meteorological satellites(FY-2H,FY-3D,and FY-4A)and their primary objectives are introduced Second,the core image navigation techniques and accuracies of the FY meteorological satellites are elaborated,including the latest geostationary(FY-2/4)and polar-orbit(FY-3)satellites.Third,the radiometric calibration techniques and accuracies of reflective solar bands,thermal infrared bands,and passive microwave bands for FY meteorological satellites are discussed.It also illustrates the latest progress of real-time calibration with the onboard calibration system and validation with different methods,including the vicarious China radiance calibration site calibration,pseudo invariant calibration site calibration,deep convective clouds calibration,and lunar calibration.Fourth,recent progress of meteorological satellite data assimilation applications and quantitative science produce are summarized at length.The main progress is in meteorological satellite data assimilation by using microwave and hyper-spectral infrared sensors in global and regional numerical weather prediction models.Lastly,the latest progress in radiative transfer,absorption and scattering calculations for satellite remote sensing is summarized,and some important research using a new radiative transfer model are illustrated.展开更多
Following the progress of satellite data assimilation in the 1990s, the combination of meteorological satellites and numerical models has changed the way scientists understand the earth. With the evolution of numerica...Following the progress of satellite data assimilation in the 1990s, the combination of meteorological satellites and numerical models has changed the way scientists understand the earth. With the evolution of numerical weather prediction models and earth system models, meteorological satellites will play a more important role in earth sciences in the future. As part of the space-based infrastructure, the Fengyun (FY) meteorological satellites have contributed to earth science sustainability studies through an open data policy and stable data quality since the first launch of the FY-1A satellite in 1988. The capability of earth system monitoring was greatly enhanced after the second-generation polar orbiting FY-3 satellites and geostationary orbiting FY-4 satellites were developed. Meanwhile, the quality of the products generated from the FY-3 and FY-4 satellites is comparable to the well-known MODIS products. FY satellite data has been utilized broadly in weather forecasting, climate and climate change investigations, environmental disaster monitoring, etc. This article reviews the instruments mounted on the FY satellites. Sensor-dependent level 1 products (radiance data) and inversion algorithm-dependent level 2 products (geophysical parameters) are introduced. As an example, some typical geophysical parameters, such as wildfires, lightning, vegetation indices, aerosol products, soil moisture, and precipitation estimation have been demonstrated and validated by in-situ observations and other well-known satellite products. To help users access the FY products, a set of data sharing systems has been developed and operated. The newly developed data sharing system based on cloud technology has been illustrated to improve the efficiency of data delivery.展开更多
Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacanc...Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacancy of the global early-morning-orbit satellite observation,working together with the FY-3C and FY-3D satellites to achieve the data coverage of early morning,morning,and afternoon orbits.The combination of these three satellites will provide global data coverage for numerical weather prediction(NWP)at 6-hour intervals,effectively improving the accuracy and time efficiency of global NWP,which is of great significance to perfect the global earth observing system.In this article,the background and meteorological requirements for the early-morning-orbit satellite are reviewed,and the specifications of the FY-3E satellite,as well as the characteristics of the onboard instrumentation for earth observations,are also introduced.In addition,the ground segment and the retrieved geophysical products are also presented.It is believed that the NWP communities will significantly benefit from an optimal temporal distribution of observations provided by the early morning,mid-morning,and afternoon satellite missions.Further benefits are expected in numerous applications such as the monitoring of severe weather/climate events,the development of improved sampling designs of the diurnal cycle for accurate climate data records,more efficient monitoring of air quality by thermal infrared remote sensing,and the quasicontinuous monitoring of the sun for space weather and climate.展开更多
In this study, the Global Navigation Satellite System （GNSS） network of China is discussed, which can be used to monitor atmospheric precipitable water vapor （PWV）. By the end of 2013, the network had 952 GNSS sit...In this study, the Global Navigation Satellite System （GNSS） network of China is discussed, which can be used to monitor atmospheric precipitable water vapor （PWV）. By the end of 2013, the network had 952 GNSS sites, including 260 belonging to the Crustal Movement Observation Network of China （CMONOC） and 692 belonging to the China Meteorological Administration GNSS network （CMAGN）. Additionally, GNSS observation collecting and data processing procedures are presented and PWV data quality control methods are investigated. PWV levels as determined by GNSS and radiosonde are compared. The results show that GNSS estimates are generally in good agreement with measurements of radio- sondes and water vapor radiometers （WVR）. The PWV retrieved by the national GNSS network is used in weather forecasting, assimilation of data into numerical weather prediction models, the validation of PWV estimates by radiosonde, and plum rain monitoring. The network is also used to monitor the total ionospheric electron content.展开更多
基金jointly supported by the National Natural Science Foundation of China(Grant U2442214)the China Meteorological Administration Youth Innovation Team(Grant No.CMA2024QN10)+1 种基金the National Defense Science and Technology Bureau’s 14th Five-Year Civil Aerospace Preresearch Project(Grant Nos.D030303 and D040204)the International Space Water Cycle Observation Constellation Program(Grant No.183311KYSB20200015).
文摘China launched its first spaceborne Precipitation Measurement Radar(PMR)on the FY-3G satellite in April 2023.To achieve the scientific goal of measuring the three-dimensional precipitation structure,evaluating the quantitative measurement ability of the PMR is critical.China operates more than 250 weather radars over the mainland.Consistency of the spaceborne radar with ground-based radars will enhance precipitation measurement ability,especially over oceans and mountains where observations are sparse.Additionally,the spaceborne radar can be used to evaluate the spatial and temporal homogeneity of the ground-based radar network.This paper focuses on comparing the PMR onboard the FY-3G satellite with S-band China New Generation Weather Radars(CINRADs).A comparison algorithm between the PMR and CINRADs has been developed,incorporating detailed quality control,attenuation correction,data optimization,spatiotemporal matching,non-uniform beam filling constraint,uniformity constraint,and frequency correction.The matched data in typical months of four seasons were selected to carry out the comparison.The data consistency between the PMR and CINRADs was analyzed.The correlation coefficient is 0.87,the deviation is 0.89 dB,and the standard deviation is 2.50 dB,based on 98226 matching samples.The results show the radar reflectivity of the PMR is quite comparable to that of the CINRADs,demonstrating that the PMR data quality is satisfactory and can be used to verify and correct data consistency among multiple ground-based radars.This work also paves the way for data fusion and joint application of satellite and ground radars in the future.
基金Supported by the Self-funded Research Project of Yunnan Meteorological Bureau in 2025(YZ202554)Key Open Laboratory of Heavy Precipitation in River Basins of the China Meteorological Administration(2023BHR-Y09).
文摘Based on conventional meteorological observation data,radar data and numerical forecast product data,the causes of the first large-scale,high-intensity and long-duration rainstorm in Dehong Prefecture during May 11-16,2022 were analyzed by using the weather dynamic diagnosis and analysis method.The results show that the rainstorm process was caused by strong uplift and condensation in the west and north of Yingjiang under the background of dry and cold northwest air circulation at 500 hPa,the absence of obvious influence of the south branch trough at 700 hPa,and strong southwest jet at 850 hPa.The southwest jet in the boundary layer provided sufficient warm water vapor,unstable energy and uplifting conditions for the rainstorm.Low-level convergence,high-level divergence and strong upward movement in the whole layer were conducive to the uplift and condensation of a large number of warm and humid air in the northwest of Yingjiang in Dehong Prefecture,which enhanced the development of mesoscale convective system(MCS)and prolonged the life history ofβmesoscale convective system.The application of satellite,radar and other mesoscale data has an important reference value for the tracking,correction,forecast and early warning of the rainstorm process.
文摘It is not only meteorological problems for the medium-range numerical weather prediction (NWP) research to be in operation,but also engineering and technological problems.Here we gener- ally described the results of research,engineering construction,operation information and testing,in the course of set-up of medium-range NWP operation system in the China National Meteorological Center.
文摘The“Outline for High-Quality Development of Meteorology(2022-2035)”was published by the State Council of the People’s Republic of China in April 2022(1).This publication highlights the essential role of meteorological disaster warnings,particularly cold spell warnings,in preventing and mitigating disasters.The outline also sets forth stricter expectations for enhancing the overall capacity of society in terms of meteorological disaster preparedness and response.
基金Supported by the People's Government of Yulin City(2023-SF-09)Yulin Meteorological Bureau(2024Y-02)Open Research Fund Project of Key Laboratory of Ecological Environment and Meteorology in the Qinling Mountains and Loess Plateau(2022Y-21).
文摘Based on the number of asthmatic children in the Children's Hospital of Yulin City,the monitoring data of daily pollen concentration,and routine meteorological and environmental monitoring data of Yulin City from 2020 to 2022,the meteorological and environmental conditions of a thunderstorm asthma event in Yulin City in northern Shaanxi on September 9,2022 were analyzed.The results show that the strong convective weather was accompanied by a strong thunderstorm,lightning,gusts,short-time heavy precipitation and small hail,and the convective activity lasted for nearly 7 h.The short-term abrupt change of allergenic substances such as artemisia pollen caused by lightning,gusts and precipitation,the sudden drop in temperature,the inversion near the surface and the stimulation of cold air were the key meteorological conditions for the subsequent outbreak of asthma.In early September in 2022,the daily average pollen concentration in Yulin City was up to 1067.9 particles/1000 mm^(2),which was 113.3%and 41.2%higher than that of the same period in 2021 and 2020,respectively.The day before the thunderstorm,the pollen concentration soared to 2680 particles/1000 mm^(2),reaching the maximum of the year.The synergistic effect of the thunderstorm event and the sharp increase in pollen concentration on the previous day provided the background of heavy pollen pollution for this outbreak of thunderstorm asthma.O_(3)concentration was consistently high on the day of thunderstorm and the day before,and the peaks of O_(3)and PM 10 concentration appeared subsequently in the afternoon of the day,which became the background of air pollution for the asthma outbreak.
基金supported jointly by the National Natural Science Foundation of China(Grant No.42105039)the China Postdoctoral Science Foundation(Grant No.2024M753587)+4 种基金the Hubei Provincial Natural Science Foundation and Meteorological Innovation and development Joint Foundation of China(Grant No.2023AFD104)the Shanghai Science and Technology Development Funds(Grant No.24QB2703600)the Open Project Fund of the China Meteorological Administration Basin Heavy Rainfall Key Laboratory(Grant No.2023BHR-Y03)the Basic Research Fund of the Institute of Heavy Rain,China Meteorological Administration,Wuhan(Grant No.202314)the Open Project Fund of the Key Open Laboratory of Hydrometeorology,China Meteorological Administration(Grant No.23SWQXM018)。
文摘This study investigated the quasi-biweekly oscillation(QBWO)of the South Asian high(SAH)center in midsummer and its possible impact on rainfall in the middle and lower reaches of the Yangtze River Basin(MLYRB),using ERA5 reanalysis data and CPC(Climate Prediction Center)Global Unified Precipitation data from 1979-2023.First,associated with the phase evolution of the QBWO of the SAH center zonally,a general systematic westward propagation of a wave train pattern along the northern margin of the SAH can be identified.Second,energy analysis indicates that this wave train pattern gains energy from the basic flow through both barotropic and baroclinic energy conversion.Compared with barotropic energy conversion,baroclinic energy conversion plays the more important role in the growth,maintenance,and propagation of the wave train pattern associated with the QBWO of the SAH center.Third,the QBWO of the SAH center leads the variation in rainfall in the MLYRB by approximately four days,and might modulate the precipitation in the MLYRB by affecting the coupling of upper-and lower-level circulation anomalies over the MLYRB.The findings of this study suggest that the QBWO of the SAH center could act as potential source of predictability of intraseasonal variation in precipitation in the MLYRB.
基金supported by the Innovation and Development Special Project of the China Meteorological Administration(Grant No.CXFZ2024J058)the Guangdong Province Basic and Applied Basic Research Foundation Meteorological Joint Fund Project(Grant No.2024A1515510036)+1 种基金the National Key R&D Program of China(Grant No.2022YFC3004101)the Technical Innovation Team Project of Guangzhou Meteorological Satellite Ground Station(Grant No.CXTD202401).
文摘FY-3G is the first polar-orbiting satellite equipped with a precipitation measurement radar(PMR)operating at Ku-andKa-band frequencies in China.In this study,we compare the reflectivity data from the FY-3G PMR Ku product and groundbasedradars(GRs)during 2024.Also,the FY-3G PMR is used as a third-party reference to evaluate the reflectivityconsistency among different GRs.The FY-3G PMR and GRs share similarities in their general distribution,characteristics,and intensity of reflectivity in strong precipitation cloud systems,though the former presents less detailed system structure.Systematic deviations between the FY-3G PMR and GRs and between GRs are comparable,albeit the reflectivity of the FY-3G PMR is generally slightly stronger than that of GRs(especially X-band GRs),with a mean bias ranging from 0.7 to 1.7dB.S-band GRs exhibit the smallest systematic deviation(STD=3.09 dB)from the FY-3G PMR,whereas the X-band GRsshow the largest(STD=3.61 dB),indirectly indicating the highest internal consistency among S-band GRs and the lowestamong X-band GRs.Besides,both S-and C-band GRs display similar deviations when paired with the FY-3G PMR as wellas when paired with their adjacent S/C-band GRs,suggesting good consistency between these two bands.In contrast,XbandGRs exhibit relatively poor consistency with S-band GRs and the FY-3G PMR,showing a deviation ranging from 3.0to 4.6 dB.
基金National Natural Science Foundation of China(12005108)。
文摘In massive multiple-input multiple-output(MIMO)systems utilizing frequency division duplexing,optimizing system performance requires user equipment(UE)to compress downlink channel state information(CSI)and transmit it to the base station(BS).As the number of antennas increases,there is a significant rise in the overhead related to CSI feedback,posing considerable challenges to the precise acquisition of CSI by the BS.Existing approaches to CSI feedback utilizing deep learning techniques face challenges such as significant feedback overhead and limited precision in the reconstruction process.This study presents a novel lightweight CSI feedback framework known as the dual attention neural network(DANet).Within the DANet architecture,a dual attention module(DAM)is designed to enhance the network's performance.This DAM includes both channel attention blocks and spatial attention blocks.The channel attention blocks direct the model's focus toward channel features rich in information content while simultaneously suppressing less significant features.This approach enables the extraction of temporal correlations within the CSI matrix.The spatial attention block aids in extracting the correlation between the delay domain and the angle domain in the CSI matrix.By enhancing neural network performance,the DAM reduces information dispersion while enhancing the representation of global interactions.Simulation results demonstrate that DANet exhibits superior normalized mean square error and cosine similarity with comparable complexity compared to existing advanced CSI feedback methods.
基金supported financially by National Natural Science Foundation of China(Grant No.42174226,42474239)National Key Research and Development Program(2022YFF0503901)China Meteorological Administration‘Ionospheric Forecast and Alerting’Youth Innovation Team(CMA2024QN09).
文摘The Triple Ionosphere Photometer(TRIPM)is a scientific payload aboard the Fengyun-3E(FY-3E)satellite,which operates in a dawn−dusk orbit.It is primarily designed for nadir observations of airglow emissions at OI 135.6 nm and N_(2)Lyman-Birge-Hopfield(LBH)bands.Due to the satellite’s dawn−dusk orbital characteristics,most of TRIPM’s field of view remains in a semi-illuminated condition.Therefore,compared with airglow data of the same bands acquired under purely daytime or nighttime conditions,applying TRIPM data poses greater challenges.This study presents the first attempt to use TRIPM data for retrieving solar extreme ultraviolet(EUV)flux.Our results demonstrate that by utilizing TRIPM data in regions where photoelectron excitation dominates as the primary radiation source,the solar EUV flux(denoted as Q_(EUV))can be retrieved.Comparisons with data from the SOHO/SEM instrument reveal excellent consistency,with a seasonal correlation coefficient(R)of at least 0.95.This work thus offers a new avenue for solar EUV flux acquisition and expands the application range of TRIPM data.
基金supported by the Central Government Guidance Funds for Local Science and Technology Development Program(grant no.ZYYD2025ZY21)the Science and Technology Plan Project of the Xinjiang Production and Construction Corps(2023AB036)+1 种基金the Xinjiang Meteorological Bureau High-Level Key Talent Programthe Natural Science Foundation of the Xinjiang Uygur Autonomous Region(2023D01A17 and 2025D01A109).
文摘Low-visibility phenomena strongly impact the environment,as well as transportation,aviation and other fields that are closely related to people's livelihoods;thus,they represent important ecological issues of social concern.Based on observation data concerning low-visibility phenomena derived from 105 national meteorological stations in Xinjiang,China over the past 20 years,we systematically analyzed the differences between manual and instrument observations for six types of low-visibility phenomena,with a focus on exploring their spatiotemporal distribution characteristics using instrument data.The results revealed that low-visibility phenomena were dominated by fog-and haze-related events(mist,fog,and haze)in northern Xinjiang and dust-related events(dust storms,blowing sand,and floating dust)in southern Xinjiang,with transitional characteristics observed in eastern Xinjiang.Compared with manual observations,the instrument measurements significantly improved the fine-scale low-visibility phenomenon identification process.On the basis of the instrument observation data,spatial-dimension analysis results indicated that low-visibility phenomena in Xinjiang were significantly influenced by terrain factors.Constrained by the Tianshan Mountains,haze-like phenomena formed a core agglomeration area in northern Xinjiang,whereas dust-and sand-related phenomena radiated outward,with the Taklimakan Desert at the center.Moreover,the gripping effect of the terrain promoted dust transmission along low-altitude channels.Temporally,fog-and haze-related phenomena occurred mainly during autumn and winter,and the proportion of these events decreased from 76.7%to 55.1%.The fog-and haze-related phenomena demonstrated a U-shaped rebound trend,while the proportion of mist phenomena decreased by 34.2%.Dust storms occurred during spring,accounting for 23.3%to 44.9%of all storms.Instrument measurement technology has the advantages of high spatial and temporal resolutions and multiparameter coordination but provides a limited dust-haze mixed-pollution identification capacity.This study provides crucial reference data for enhancing the understanding of low-visibility events in Xinjiang and the potential responses while improving the accuracy of pollution source tracking and meteorological process diagnosis tasks.
基金supported by the National Natural Science Foundation of China (NSFC) (Grant No.42205044)Feng Yun Application Pioneering Project (FY-APP) Innovation Center for Feng Yun Meteorological Satellite (FYSIC) Special Project (FY-APP-XC-2023.04)the Wuxi University Research Start-up Fund for Recruited Talent。
文摘Ground-based radar is the primary means by which severe storms are monitored and tracked;however, due to limited coverage, important data is often missed over ocean and mountainous areas. On the other hand, geostationary(GEO)weather satellites provide continuous observations with seamless coverage with advanced imager, despite their limited capability to penetrate clouds. Combining satellite and ground-radar observations could exploit the advantages of both techniques, providing tracking capability close to that of ground radar while maintaining full spatial coverage. This study presents a novel method called Multi-dimensional satellite Observation information for Radar Estimation(MORE) to reconstruct radar composite reflectivity(CREF). Deep learning techniques are important components of MORE for estimating CREF from China's Fengyun-4B(FY-4B) GEO satellite observations. Two models are developed: an infraredonly(IR-Single) model available for all times, and a visible-infrared(VIS+IR) model for daytime applications. These models incorporate multi-dimensional satellite observation information, including temporal, spatial, spectral, and viewing angle information, to enhance the accuracy of radar echo reconstruction. Results demonstrate that the VIS+IR model outperforms the IR-Single model, and both models achieves a root-mean-square error(RMSE) of less than 6 dBZ and a coefficient of determination(R~2) of greater than 0.7. The models effectively reconstruct radar echoes, including strong echoes exceeding 50 dBZ, and show good agreement with precipitation data in radar-blind areas. This study offers a valuable solution for severe weather monitoring and tracking in regions lacking ground-based radar observations, and provides a potential tool for enhanced data assimilation in numerical weather prediction(NWP) models.
基金supported by the National Natural Science Foundation of China(Grant No.42375192).
文摘The calculation of viewing and solar geometry angles is a critical first step in retrieving atmospheric and surface variables from geostationary satellite observations.Whereas the viewing angles for geostationary satellites are not timevarying,a primary source of inaccuracy in solar positioning is the use of a single timestamp.Since pixel scanning times can differ significantly across the field-of-view disk(e.g.,by approximately 13 min for Fengyun-4B),this practice leads to errors of up to±2°in solar zenith angle,which translates to±50 W m^(−2) in extraterrestrial irradiance;the errors in solar azimuth angle can exceed±100°.Beyond scanning time,this work also quantifies the impact of other inputs—including altitude,surface pressure,air temperature,difference between Terrestrial Time and Universal Time,and atmospheric refraction—on the resulting angles.A comparison of our precise calculations with the official National Satellite Meteorological Center L1_GEO product shows an accuracy within 0.1°,confirming its utility for most retrieval tasks.To facilitate higher precision when required,this work releases the corresponding satellite and solar positioning codes in both R and Python.
基金National Key Research and Development Program of China (2023YFB3905801)。
文摘Accurate calibration of China's new generation ground-based polarimetric radar(GR) network is crucial yet challenging. Although application of the Dual-frequency Precipitation Radar(DPR) of the Global Precipitation Measurement Core Observatory for GR assessment is well-established, current methodologies are inherently limited. Focusing on three GRs in the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)—strategically selected for their high overlapping coverage(>65%) and distinct from single GR or less dense coverage studies—this work introduces key refinements by integrating innovative enhancements into the volume-matching method(VMM), reflecting a systematic approach to mitigating potential error sources. Specifically, we integrate: 1) a novel frequency correction method that adapts to DPR-observed precipitation phase and type, replacing assumption-based polynomial fitting;and 2) a precise beam time-difference matching approach(accuracy < 1 s) to minimize temporal mismatch errors, which improves upon coarser time averaging methods. Furthermore, we developed statistically robust, optimized threshold criteria based on systematic sensitivity analyses using 11 quality control factors, including precipitation type, bright band effects, and attenuation correction limitations. These criteria establish an enhanced protocol designed to minimize errors arising from instrumental, frequency, and scanning differences. Application of this enhanced methodology to the GBA GRs(2021–2023) yielded a significantly improved matching accuracy(correlation coefficient, CC: 0.90–0.95;standard deviation,STD: 1.2–1.6 dB). A unique contribution of this work is the quantitative estimation of historical calibration errors and operational stability, which was achieved by linking VMM results with operational GR calibration and maintenance records. This analysis revealed decreasing STD trends and identified specific calibration-related events, such as an underestimation of approximately 2.43 dB for the Shenzhen radar following calibration in 2023. Consequently, the refined methodology provides a robust framework for ongoing GR network monitoring and offers a validated pathway for authenticating China's Fengyun-3G(FY-3G) satellite precipitation measurement radar(PMR) data.
基金National Natural Science Foundation of China(42030611)Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK0103)。
文摘Autumn rain in western China(ARWC)is a unique and significant precipitation phenomenon that occurs during the summer-to-winter transition of the atmospheric circulation.Using the fifth generation of global climate and weather reanalysis data from the European Centre for Medium-Range Weather Forecasts and CN05.1 grid precipitation data,this study examined the anomalous characteristics and mechanisms of ARWC by combining the synergistic effect of the westerly jet and meridional wind.Over the past 60 years,ARWC has exhibited significant interdecadal and interannual variations,as well as a north-south seesaw pattern.The westerly jet index(meridional wind index)exhibited a negative(positive)correlation with precipitation in the northern autumn rain zone(NARZ),and a positive(negative)correlation with precipitation in the southern autumn rain zone(SARZ).The coupling of a weak meridional southerly wind with a southward westerly jet and a strong meridional southerly wind with a northward westerly jet are the two primary modes that synergistically influence the ARWC.These synergistic effects cause significant atmospheric changes throughout the troposphere.The contrasting circulation structure,temperature advection,vertical motion,and water vapor flux contributed to the opposite precipitation anomalies observed in the NARZ and SARZ.A new comprehensive index that reflects the coupled synergistic effect is proposed to characterize the anomalous changes in ARWC.This study improves the understanding of the anomalous characteristics and mechanisms of ARWC.
基金supported jointly by the Natural Science Foundation of Yunnan Province(Grant No.202501CF070059)the National Natural Science Foundation of China(Grant No.42205021)+5 种基金the Yunnan Provincial Science and Technology Department(Grant Nos.202505AB350001 and202403AP140009)the Yunnan Southwest United Graduate School Science and Technology Special Project(Award No.202302AP370003)the Scientific Research Fund Project of Yunnan Education Department(Grant No.2025Y0111)the Practical Innovation Project of Postgraduate Students in the Academic Degree of Yunnan University(Grant No.KC-24248868)the Practical Innovation Project of Postgraduate Students in the Professional Degree of Yunnan University(Grant No.ZC-24248604)the Youth Science and Technology Fund Project of Gansu Province(Grant No.24JRRA1186)。
文摘The commencement of the tropical Asian summer monsoon(TASM)in May is a crucial phase in its seasonal evolution,with critical implications for agriculture and water resources.Based on observational and reanalysis data,this study finds that the relationship between El Nino-Southern Oscillation(ENSO)and monsoon commencement experiences a notable interdecadal strengthening after 1976/77.While the response of tropical tropospheric temperature to ENSO remains largely unchanged,ENSO induces a stronger Walker circulation,a more pronounced equatorial Rossby wave,and an intensified extratropical Rossby wave train after 1976/77.These enhanced atmospheric processes,which directly reinforce the ENSO-TASM commencement relationship,are likely driven by interdecadal shifts in the structure and variance of ENSO.Post-1976/77,ENSO displays increased variance and a more coherent structure,with more pronounced sea surface temperature anomalies in the western North Pacific and subtropical North Pacific.Given the limitations of observational data,a 1000-year piControl experiment further confirms the role of ENSO variance changes in strengthening its influence on monsoon commencement.Our findings underscore the critical influence of evolving ENSO characteristics on climate anomalies such as monsoon commencement,offering potential insights for short-term climate prediction.
基金funded by the Science and Technology Development Fund of Macao Special Administrative Region(Grant No.0009/2024/RIB1)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030004).
文摘Persistent severe rainfall(PSR)events,defined as regional-scale rainfall processes with daily precipitation no less than 50 mm for at least three consecutive days,frequently occur over South China(SC)and the middle-to-lower Yangtze River Basin(MLYRB),with distinct dynamic mechanisms and moisture conditions in the two regions.Based on daily precipitation observations from China’s national meteorological stations and ERA5 reanalysis during 2012-21,this study investigates the spatiotemporal distribution of PSR events in SC and MLYRB and their associated three-dimensional circulation dynamics.The analysis integrates diagnostics of 200 hPa wave activity flux,perturbation streamfunction,500 hPa geopotential height,850 hPa wind fields,and integrated water vapor transport.Results show that PSR events in SC mainly occur during May-June,with rainfall centers over coastal and central Guangdong and Guangxi.In contrast,MLYRB events peak during June-July,with a banded rainfall pattern along the middle-to-lower Yangtze River.Dynamical diagnostics indicate that,in SC,sustained northwest-southeast propagation of 200 hPa disturbances,the southward shift of the 500 hPa trough,and steady subtropical high maintenance provide continuous dynamical support.Concurrently,strong and persistent 850 hPa southwesterlies and long-lasting moisture transport form favorable moisture conditions.In contrast,MLYRB events are marked by rapid phase transitions of 200 hPa streamfunction anomalies and northward-westward expansion of the 500 hPa subtropical high,triggering intense rainfall development.Simultaneously,abrupt enhancement of 850 hPa southwesterlies and rapid formation of a southwest moisture corridor ensure abundant and timely moisture supply,facilitating PSR onset.
基金funded by the National Key R&D Program of China(Grant Nos.2018YFB0504900 and 2015AA123700)
文摘In this paper,the latest progress,major achievements and future plans of Chinese meteorological satellites and the core data processing techniques are discussed.First,the latest three FengYun(FY)meteorological satellites(FY-2H,FY-3D,and FY-4A)and their primary objectives are introduced Second,the core image navigation techniques and accuracies of the FY meteorological satellites are elaborated,including the latest geostationary(FY-2/4)and polar-orbit(FY-3)satellites.Third,the radiometric calibration techniques and accuracies of reflective solar bands,thermal infrared bands,and passive microwave bands for FY meteorological satellites are discussed.It also illustrates the latest progress of real-time calibration with the onboard calibration system and validation with different methods,including the vicarious China radiance calibration site calibration,pseudo invariant calibration site calibration,deep convective clouds calibration,and lunar calibration.Fourth,recent progress of meteorological satellite data assimilation applications and quantitative science produce are summarized at length.The main progress is in meteorological satellite data assimilation by using microwave and hyper-spectral infrared sensors in global and regional numerical weather prediction models.Lastly,the latest progress in radiative transfer,absorption and scattering calculations for satellite remote sensing is summarized,and some important research using a new radiative transfer model are illustrated.
基金This work was supported by the National Key Research and Development Program of China(2018YFB0504900,2018YFB0504905).
文摘Following the progress of satellite data assimilation in the 1990s, the combination of meteorological satellites and numerical models has changed the way scientists understand the earth. With the evolution of numerical weather prediction models and earth system models, meteorological satellites will play a more important role in earth sciences in the future. As part of the space-based infrastructure, the Fengyun (FY) meteorological satellites have contributed to earth science sustainability studies through an open data policy and stable data quality since the first launch of the FY-1A satellite in 1988. The capability of earth system monitoring was greatly enhanced after the second-generation polar orbiting FY-3 satellites and geostationary orbiting FY-4 satellites were developed. Meanwhile, the quality of the products generated from the FY-3 and FY-4 satellites is comparable to the well-known MODIS products. FY satellite data has been utilized broadly in weather forecasting, climate and climate change investigations, environmental disaster monitoring, etc. This article reviews the instruments mounted on the FY satellites. Sensor-dependent level 1 products (radiance data) and inversion algorithm-dependent level 2 products (geophysical parameters) are introduced. As an example, some typical geophysical parameters, such as wildfires, lightning, vegetation indices, aerosol products, soil moisture, and precipitation estimation have been demonstrated and validated by in-situ observations and other well-known satellite products. To help users access the FY products, a set of data sharing systems has been developed and operated. The newly developed data sharing system based on cloud technology has been illustrated to improve the efficiency of data delivery.
基金funded by the FY3-03 project and the National Key Technology Research and Development Program of China(Grant Nos.2018YFB0504900 and 2018YFB0504905)。
文摘Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacancy of the global early-morning-orbit satellite observation,working together with the FY-3C and FY-3D satellites to achieve the data coverage of early morning,morning,and afternoon orbits.The combination of these three satellites will provide global data coverage for numerical weather prediction(NWP)at 6-hour intervals,effectively improving the accuracy and time efficiency of global NWP,which is of great significance to perfect the global earth observing system.In this article,the background and meteorological requirements for the early-morning-orbit satellite are reviewed,and the specifications of the FY-3E satellite,as well as the characteristics of the onboard instrumentation for earth observations,are also introduced.In addition,the ground segment and the retrieved geophysical products are also presented.It is believed that the NWP communities will significantly benefit from an optimal temporal distribution of observations provided by the early morning,mid-morning,and afternoon satellite missions.Further benefits are expected in numerous applications such as the monitoring of severe weather/climate events,the development of improved sampling designs of the diurnal cycle for accurate climate data records,more efficient monitoring of air quality by thermal infrared remote sensing,and the quasicontinuous monitoring of the sun for space weather and climate.
基金financially supported by the Special Fund for Meteorological Scientific Research in the Public Interest(GYHY201406012)the National Natural Science Foundation of China(41275114)a construction fund for CMONOC
文摘In this study, the Global Navigation Satellite System （GNSS） network of China is discussed, which can be used to monitor atmospheric precipitable water vapor （PWV）. By the end of 2013, the network had 952 GNSS sites, including 260 belonging to the Crustal Movement Observation Network of China （CMONOC） and 692 belonging to the China Meteorological Administration GNSS network （CMAGN）. Additionally, GNSS observation collecting and data processing procedures are presented and PWV data quality control methods are investigated. PWV levels as determined by GNSS and radiosonde are compared. The results show that GNSS estimates are generally in good agreement with measurements of radio- sondes and water vapor radiometers （WVR）. The PWV retrieved by the national GNSS network is used in weather forecasting, assimilation of data into numerical weather prediction models, the validation of PWV estimates by radiosonde, and plum rain monitoring. The network is also used to monitor the total ionospheric electron content.
