ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 52,Issue 1,2026 Table of Contents
2026, 52(1):1-15.
DOI: 10.7519/j.issn.1000-0526.2025.041301
Abstract:
Based on the data from the South China field observation experiment in summer 2023, the contribution of assimilating Beidou sounding data from the Guangdong network to the forecast of Typhoon Saola (No.2309) is analyzed by means of the three-dimensional variational assimilation method of the Weather Research and Forecasting Model (WRF) and its variational assimilation system (WRFDA). The application prospects of the fully operationalized new Beidou sounding observation system are also explored. The study reveals that Beidou sounding has basically the same quality as L-band sounding at the same station, and as ERA5 reanalysis data and FNL analysis field data, so it has high observational value. The effective assimilation of Beidou sounding data can adjust the temperature, humidity, and wind fields of the background field to varying degrees, significantly improving the quality of analysis field, and also has corresponding improvements in the forecast of the typhoon’s track, intensity, and precipitation forecast. Among them, the track RMSE is reduced by 11.87% compared to the non-assimilated Beidou sounding.
Based on the data from the South China field observation experiment in summer 2023, the contribution of assimilating Beidou sounding data from the Guangdong network to the forecast of Typhoon Saola (No.2309) is analyzed by means of the three-dimensional variational assimilation method of the Weather Research and Forecasting Model (WRF) and its variational assimilation system (WRFDA). The application prospects of the fully operationalized new Beidou sounding observation system are also explored. The study reveals that Beidou sounding has basically the same quality as L-band sounding at the same station, and as ERA5 reanalysis data and FNL analysis field data, so it has high observational value. The effective assimilation of Beidou sounding data can adjust the temperature, humidity, and wind fields of the background field to varying degrees, significantly improving the quality of analysis field, and also has corresponding improvements in the forecast of the typhoon’s track, intensity, and precipitation forecast. Among them, the track RMSE is reduced by 11.87% compared to the non-assimilated Beidou sounding.
2026, 52(1):16-28.
DOI: 10.7519/j.issn.1000-0526.2025.053001
Abstract:
Based on the station observation, sounding data, FY-4B satellite images, Doppler weather radar data and ERA5 reanalysis data, the characteristics and causes of the anomalous change in the intensity of Super Typhoon Yagi in 2024 are analyzed. It is found that Typhoon Yagi is the stongest landfalling autumn typhoon in China since 1981, and it maintained super typhoon level (SuperTY) in the South China Sea for 64 h, making it the longest-lasting super typhoon in the region. Typhoon Yagi experienced three rapid intensification (RI) processes. In one of these processes, it reached the level of extreme rapid intensification (ERI), with its 12 h and 24 h intensity increase amplitudes being the highest in the South China Sea since 1981. The robust southwestern monsoon supplied abundant moisture for the typhoon development, while the stable subtropical high and continental airflow transported convectively unstable air masses from land toward the typhoon’s core, which enhanced the atmospheric potential instability near the typhoon circulation. Meanwhile, the weakened environmental vertical wind shear and favorable upper-level outflow conditions collectively facilitated the RI and the sustained peak intensity. The sea surface temperature in the northern South China Sea exceeded 30℃, 1-2℃ above normal, providing substantial latent heat flux to the atmosphere. During Yagi’s RI, a significant increase in kinetic energy within the typhoon’s domain was observed. The primary driver of this kinetic energy growth was a sharp rise in kinetic energy production. Moreover, the vertical and horizontal kinetic energy transports also contributed a lot.
Based on the station observation, sounding data, FY-4B satellite images, Doppler weather radar data and ERA5 reanalysis data, the characteristics and causes of the anomalous change in the intensity of Super Typhoon Yagi in 2024 are analyzed. It is found that Typhoon Yagi is the stongest landfalling autumn typhoon in China since 1981, and it maintained super typhoon level (SuperTY) in the South China Sea for 64 h, making it the longest-lasting super typhoon in the region. Typhoon Yagi experienced three rapid intensification (RI) processes. In one of these processes, it reached the level of extreme rapid intensification (ERI), with its 12 h and 24 h intensity increase amplitudes being the highest in the South China Sea since 1981. The robust southwestern monsoon supplied abundant moisture for the typhoon development, while the stable subtropical high and continental airflow transported convectively unstable air masses from land toward the typhoon’s core, which enhanced the atmospheric potential instability near the typhoon circulation. Meanwhile, the weakened environmental vertical wind shear and favorable upper-level outflow conditions collectively facilitated the RI and the sustained peak intensity. The sea surface temperature in the northern South China Sea exceeded 30℃, 1-2℃ above normal, providing substantial latent heat flux to the atmosphere. During Yagi’s RI, a significant increase in kinetic energy within the typhoon’s domain was observed. The primary driver of this kinetic energy growth was a sharp rise in kinetic energy production. Moreover, the vertical and horizontal kinetic energy transports also contributed a lot.
2026, 52(1):29-43.
DOI: 10.7519/j.issn.1000-0526.2025.051901
Abstract:
Multiple DSG5 raindrop disdrometers are utilized to analyze the raindrop size distribution of the residual vortex of Typhoon Haikui in 2023 in the Pearl River Delta, and the performance of radar quantitative precipitation estimation (QPE) algorithms based on observed raindrop size distribution in the S/X-bands is evaluated. The results indicate that the impact of the residual vortex of Haikui on rainfall in the Pearl River Delta can be divided into two main stages. The first stage is primarily influenced by the convergence of the southwest monsoon and easterly airflow on the eastern side of the vortex itself, with a deep moisture convergence layer. The microphysical processes of rainfall are relatively uniform with higher number concentrations and relatively small particle sizes of raindrops. The second stage is characterized by severe rainfall caused by the convergence of southerly winds in the boundary layer on the outskirts of the residual vortex, with a shallower moisture convergence layer. The rainfall particles are more dispersed, with more rainfall events featuring large diameters and low number concentration of raindrops. Overall, medium-sized raindrops make a major contribution to the total rainfall amount, but as rainfall intensity increases, the contribution of extremely large raindrops to rainfall intensity at the second stage is significantly higher than that at the first stage. The dual-polarization parameters derived from raindrop size distribution of this process shows that, under the same rainfall intensity (R), horizontal reflectivity factor (ZH), specific differential phase (KDP), and differential reflectivity (ZDR) at the first stage are smaller than those at the second stage. The deviation of QPE algorithms in the S/X-bands calculated based on disdrometers data shows that, R(ZH) has relatively large biases in both the S-band and X-band, while the bias of R(ZH, ZDR) is relatively small in the S-band but increases significantly with increasing rainfall intensity in the X-band while R(KDP) has better performance in the X-band. R(KDP, ZDR) performs the best in both the S/X-band and is minimally affected by changes in raindrop size distribution, with little difference between the two stages.
Multiple DSG5 raindrop disdrometers are utilized to analyze the raindrop size distribution of the residual vortex of Typhoon Haikui in 2023 in the Pearl River Delta, and the performance of radar quantitative precipitation estimation (QPE) algorithms based on observed raindrop size distribution in the S/X-bands is evaluated. The results indicate that the impact of the residual vortex of Haikui on rainfall in the Pearl River Delta can be divided into two main stages. The first stage is primarily influenced by the convergence of the southwest monsoon and easterly airflow on the eastern side of the vortex itself, with a deep moisture convergence layer. The microphysical processes of rainfall are relatively uniform with higher number concentrations and relatively small particle sizes of raindrops. The second stage is characterized by severe rainfall caused by the convergence of southerly winds in the boundary layer on the outskirts of the residual vortex, with a shallower moisture convergence layer. The rainfall particles are more dispersed, with more rainfall events featuring large diameters and low number concentration of raindrops. Overall, medium-sized raindrops make a major contribution to the total rainfall amount, but as rainfall intensity increases, the contribution of extremely large raindrops to rainfall intensity at the second stage is significantly higher than that at the first stage. The dual-polarization parameters derived from raindrop size distribution of this process shows that, under the same rainfall intensity (R), horizontal reflectivity factor (ZH), specific differential phase (KDP), and differential reflectivity (ZDR) at the first stage are smaller than those at the second stage. The deviation of QPE algorithms in the S/X-bands calculated based on disdrometers data shows that, R(ZH) has relatively large biases in both the S-band and X-band, while the bias of R(ZH, ZDR) is relatively small in the S-band but increases significantly with increasing rainfall intensity in the X-band while R(KDP) has better performance in the X-band. R(KDP, ZDR) performs the best in both the S/X-band and is minimally affected by changes in raindrop size distribution, with little difference between the two stages.
2026, 52(1):44-55.
DOI: 10.7519/j.issn.1000-0526.2025.031401
Abstract:
Utilizing best-track data of typhoon provided by the China Meteorological Administration (CMA), this paper conducts an analysis of the climatic characteristics of typhoons (TCs) having entered the Huanghai and Bohai Sea Region (30°-50°N, 110°-130°E) from 1949 to 2020. The results indicate that, on average, 4.3 TCs enter the Huanghai and Bohai Sea (HBS) Region annually, showing a significant increasing trend in the percentage of HBS TCs in the western North Pacific typhoons (WNP TCs). HBS TCs are active between April and November. Since the 1990s, there has been an increase in HBS TCs activity during autumn. The primary genesis region for HBS TCs is located between 5°N to 30°N and 120°E to 160°E. Since the 1950s, it has been continuously shifting westward. Prior to the 1980s, there was a gradual northward trend, which was followed by a southward trend accompanied by the phenomenon of “autumn expansion” after the 1990s. Most HBS TCs enter the HBS via distant sea tracks, traveling a considerable distance from land. Then, there are HBS TCs that change direction or move northward during their offshore or landing activities. The other HBS TCs dissipate after landing, continue moving westward at high latitudes, or turn westward within the Yellow Sea. 51.8% of HBS TCs undergo extratropical transition, and among them, 28.6% strengthen after the transition. The intensification following extratropical transition mainly occurs from June to October, peaking in August and September. The central and southern regions of East China and the southern part of the Sea of Japan are the two main areas where such intensification is concentrated.
Utilizing best-track data of typhoon provided by the China Meteorological Administration (CMA), this paper conducts an analysis of the climatic characteristics of typhoons (TCs) having entered the Huanghai and Bohai Sea Region (30°-50°N, 110°-130°E) from 1949 to 2020. The results indicate that, on average, 4.3 TCs enter the Huanghai and Bohai Sea (HBS) Region annually, showing a significant increasing trend in the percentage of HBS TCs in the western North Pacific typhoons (WNP TCs). HBS TCs are active between April and November. Since the 1990s, there has been an increase in HBS TCs activity during autumn. The primary genesis region for HBS TCs is located between 5°N to 30°N and 120°E to 160°E. Since the 1950s, it has been continuously shifting westward. Prior to the 1980s, there was a gradual northward trend, which was followed by a southward trend accompanied by the phenomenon of “autumn expansion” after the 1990s. Most HBS TCs enter the HBS via distant sea tracks, traveling a considerable distance from land. Then, there are HBS TCs that change direction or move northward during their offshore or landing activities. The other HBS TCs dissipate after landing, continue moving westward at high latitudes, or turn westward within the Yellow Sea. 51.8% of HBS TCs undergo extratropical transition, and among them, 28.6% strengthen after the transition. The intensification following extratropical transition mainly occurs from June to October, peaking in August and September. The central and southern regions of East China and the southern part of the Sea of Japan are the two main areas where such intensification is concentrated.
PING Fan
,
YANG Lei
,
YUAN Liang
,
CAO Shiteng
,
YANG Xue
,
YUAN Chao
,
GUO Yijia
,
WANG Gaili
,
SUN Li
2026, 52(1):56-69.
DOI: 10.7519/j.issn.1000-0526.2025.072201
Abstract:
Affected by a rare precipitation system with 16 mesovortices (referred to as MV), a local short-time rainstorm process occurred in Fushun of Liaoning Province on the night of 4 August 2023. In this paper, the formation mechanism of MV and the observation characteristics of MV that produced heavy precipitation are analyzed based on multi-source data such as X-band phased array radar. The results show that Fushun was influenced by the high-level trough and low-level shear line and had the abundant water vapor and low lifting condensation height, which were favorable environmental conditions for short-time rainstorm. When the angle between the convergence line and the isotherm line increased under the strong vertical wind shear, a total of 16 MV were detected by X-band phased array radar. The average duration, thickness and top height of the MV were 17 min, 1.7 km and 3.5 km, respectively. These vortices are low-level shallow MV. There were up to 49 times of heavy precipitation with the rainfall amount reaching 10 mm within 5 min, and the average distance between the heavy precipitation stations and MV was only 6.2 km. There were 44 times of heavy precipitation caused by the first and fourth MV, accounting for 89% of all heavy precipitation. Compared to other MV, the two MV that produced heavy precipitation had a longer lifetime and moving distance, with stronger rotation intensity and greater thickness. The two MV were both generated during the stage where the boundary layer jet was significantly enhanced, the 0-1 km wind vector difference exceeded 15 m·s-1 and the surface temperature was higher than 28℃. In the early stage of the MV, the low-level rotation was even stronger reaching the standard of moderate intensity mesoscale cyclones, with vigorous storm developing above. There was no heavy precipitation near the MV at this time. Subsequently, the rotational speed of the MV diminished, and the storm height rapidly decreased. At this moment, heavy precipitation occurred immediately near the MV. In addition, there was a phenomenon of several weaker MV merging with MV that produced heavy precipitation, which was beneficial for the MV sustainment. In conclusion, the evolution of the position and rotational intensity of MV was crucial for the forecasting of heavy precipitation.
Affected by a rare precipitation system with 16 mesovortices (referred to as MV), a local short-time rainstorm process occurred in Fushun of Liaoning Province on the night of 4 August 2023. In this paper, the formation mechanism of MV and the observation characteristics of MV that produced heavy precipitation are analyzed based on multi-source data such as X-band phased array radar. The results show that Fushun was influenced by the high-level trough and low-level shear line and had the abundant water vapor and low lifting condensation height, which were favorable environmental conditions for short-time rainstorm. When the angle between the convergence line and the isotherm line increased under the strong vertical wind shear, a total of 16 MV were detected by X-band phased array radar. The average duration, thickness and top height of the MV were 17 min, 1.7 km and 3.5 km, respectively. These vortices are low-level shallow MV. There were up to 49 times of heavy precipitation with the rainfall amount reaching 10 mm within 5 min, and the average distance between the heavy precipitation stations and MV was only 6.2 km. There were 44 times of heavy precipitation caused by the first and fourth MV, accounting for 89% of all heavy precipitation. Compared to other MV, the two MV that produced heavy precipitation had a longer lifetime and moving distance, with stronger rotation intensity and greater thickness. The two MV were both generated during the stage where the boundary layer jet was significantly enhanced, the 0-1 km wind vector difference exceeded 15 m·s-1 and the surface temperature was higher than 28℃. In the early stage of the MV, the low-level rotation was even stronger reaching the standard of moderate intensity mesoscale cyclones, with vigorous storm developing above. There was no heavy precipitation near the MV at this time. Subsequently, the rotational speed of the MV diminished, and the storm height rapidly decreased. At this moment, heavy precipitation occurred immediately near the MV. In addition, there was a phenomenon of several weaker MV merging with MV that produced heavy precipitation, which was beneficial for the MV sustainment. In conclusion, the evolution of the position and rotational intensity of MV was crucial for the forecasting of heavy precipitation.
2026, 52(1):70-82.
DOI: 10.7519/j.issn.1000-0526.2025.071801
Abstract:
Using automatic station data, ERA5 reanalysis data, and radar detection data, this paper analyzes the synoptic situation, mesoscale convective system and propagation characteristics, as well as the combined effects of the parallel ridge-valley in East Sichuan Region and the Daba Mountain on a heavy rainfall event in 17-18 June 2021. The results show that the heavy rainfall occurred in the junction area of the Daba Mountain and the parallel ridge-valley region, and it went through three stages of evolution of mesoscale convective systems. Multiple northeast-southwest oriented strip-shaped convective systems were organized developing along the mountains of the parallel ridge-valley, with convective cell train effects and rainband stacking effects intensifying the precipitation. The cold front over the basin and the surface convergence line played an important role in triggering and organizing the mesoscale convective systems. Additionally, the cold front over the basin interacted with the eastward-moving cold air invading along the Wushan Mountain and the Yangtze River Valley, leading to the strengthening and maintenance of the convective systems. The role of the Daba Mountain in the heavy rainfall was reflected in the blocking effect and thermodynamic uplift. The windward slope of the terrain had a blocking and converging effect on the transport of water vapor and energy, with east-west oriented water vapor convergence belts and high pseudoequivalent potential temperature areas maintaining on the southern slope of the Daba Mountain. The boundary layer frontogenesis, positive vorticity areas, low-level convergence areas, and upward motion areas developed along the slope of the Daba Mountain. The role of the parallel ridge-valley terrain in precipitation was reflected in the aggregation of boundary layer water vapor, the quasi-stationary maintenance of the surface convergence line, and the formation of mesoscale occlusion fronts, which caused the mesoscale convective systems to move northward to the southern slope of the Daba Mountain. The mesoscale convective systems stagnated there and developed vigorously, thus triggering this heavy rainfall event in the mountainous area.
Using automatic station data, ERA5 reanalysis data, and radar detection data, this paper analyzes the synoptic situation, mesoscale convective system and propagation characteristics, as well as the combined effects of the parallel ridge-valley in East Sichuan Region and the Daba Mountain on a heavy rainfall event in 17-18 June 2021. The results show that the heavy rainfall occurred in the junction area of the Daba Mountain and the parallel ridge-valley region, and it went through three stages of evolution of mesoscale convective systems. Multiple northeast-southwest oriented strip-shaped convective systems were organized developing along the mountains of the parallel ridge-valley, with convective cell train effects and rainband stacking effects intensifying the precipitation. The cold front over the basin and the surface convergence line played an important role in triggering and organizing the mesoscale convective systems. Additionally, the cold front over the basin interacted with the eastward-moving cold air invading along the Wushan Mountain and the Yangtze River Valley, leading to the strengthening and maintenance of the convective systems. The role of the Daba Mountain in the heavy rainfall was reflected in the blocking effect and thermodynamic uplift. The windward slope of the terrain had a blocking and converging effect on the transport of water vapor and energy, with east-west oriented water vapor convergence belts and high pseudoequivalent potential temperature areas maintaining on the southern slope of the Daba Mountain. The boundary layer frontogenesis, positive vorticity areas, low-level convergence areas, and upward motion areas developed along the slope of the Daba Mountain. The role of the parallel ridge-valley terrain in precipitation was reflected in the aggregation of boundary layer water vapor, the quasi-stationary maintenance of the surface convergence line, and the formation of mesoscale occlusion fronts, which caused the mesoscale convective systems to move northward to the southern slope of the Daba Mountain. The mesoscale convective systems stagnated there and developed vigorously, thus triggering this heavy rainfall event in the mountainous area.
2026, 52(1):83-93.
DOI: 10.7519/j.issn.1000-0526.2025.073101
Abstract:
Based on surface observations, lightning location data, Doppler radar data, and ECMWF ERA5 reanalysis data, the characteristics of cloud-to-ground (CG) lightning activity of the sea-effect snowfall with CG lightning in Shandong Peninsula from November to the following February during 2017-2023 are studied. The results are as follows. The CG lightning mainly occurs in the sea-effect snowfall over the Bohai Sea from November to the following January, with the highest frequency in November and gradually decreasing frequency from December to the following January, and there is no CG observed in February. The diurnal variation of CG lightning shows a multi-peak structure, primarily from wee hours to morning. The frequency and distribution range of CG lightning in sea-effect snowfall of sleet type are greater than those of pure snow type. 90% of the thunderstorm days with pure snow type sea-effect snowfall have CG lightning less than 10 times. CG lightning during the two types of sea-effect snowfall is distributed both over the Bohai Sea and on land, and the distribution on land is connected to the terrain. CG lightning of sleet type is mainly distributed over the Bohai Sea, whereas CG lightning of pure snow type is mainly distributed on land, generally near areas of heavy snow, and in the northwest direction of the center of heavy snow (upwind direction). The convective development height of the sleet type CG lightning is higher than that of pure snow type. The occurrence time and location of CG lightning have a certain indicative effect on short-time imminent warning of snowfall period and location of heavy sea-effect snowfall, and the snowfall intensity increases significantly within 0-2 h after the occurrence of CG lightning in sea-effect snowfall. At the heavy snowfall centers near CG lightning locations, snowfall intensity may reach the level of blizzards.
Based on surface observations, lightning location data, Doppler radar data, and ECMWF ERA5 reanalysis data, the characteristics of cloud-to-ground (CG) lightning activity of the sea-effect snowfall with CG lightning in Shandong Peninsula from November to the following February during 2017-2023 are studied. The results are as follows. The CG lightning mainly occurs in the sea-effect snowfall over the Bohai Sea from November to the following January, with the highest frequency in November and gradually decreasing frequency from December to the following January, and there is no CG observed in February. The diurnal variation of CG lightning shows a multi-peak structure, primarily from wee hours to morning. The frequency and distribution range of CG lightning in sea-effect snowfall of sleet type are greater than those of pure snow type. 90% of the thunderstorm days with pure snow type sea-effect snowfall have CG lightning less than 10 times. CG lightning during the two types of sea-effect snowfall is distributed both over the Bohai Sea and on land, and the distribution on land is connected to the terrain. CG lightning of sleet type is mainly distributed over the Bohai Sea, whereas CG lightning of pure snow type is mainly distributed on land, generally near areas of heavy snow, and in the northwest direction of the center of heavy snow (upwind direction). The convective development height of the sleet type CG lightning is higher than that of pure snow type. The occurrence time and location of CG lightning have a certain indicative effect on short-time imminent warning of snowfall period and location of heavy sea-effect snowfall, and the snowfall intensity increases significantly within 0-2 h after the occurrence of CG lightning in sea-effect snowfall. At the heavy snowfall centers near CG lightning locations, snowfall intensity may reach the level of blizzards.
2026, 52(1):94-104.
DOI: 10.7519/j.issn.1000-0526.2025.072901
Abstract:
China’s Spring Festival is usually between 20 January and 26 February every year. The Spring Festival holiday is the golden week of tourism, bringing high tourism flow. The Spring Festival tourism shows climate-driven characteristics. In this paper, human comfort index and trend analysis method are used to analyze the spatial and temporal characteristics of favorable and unfavorable tourism climate conditions during the Spring Festival holiday in China. The results show that during the Spring Festival holiday from 1991 to 2020, there is a significant north-south difference for temperature and precipitation in China. The average temperature in most areas south of the Yangtze River (Jiangnan) is above 5℃, while that in most parts of Heilongjiang and northeastern Inner Mongolia is below -15℃. The precipitation is mainly concentrated in Jiangnan and the central eastern part of South China. The number of human comfort days is more than 10 days in most parts of South China, Yunnan, and southern Sichuan, beneficial for winter resort. The number of snow cover days is more than 15 days in the majority of Northeast China, central and northeastern Inner Mongolia, and northern Xinjiang, which is conducive to ice-snow tourism. Precipitation and fog mainly affect tourism in southern China, while strong winds and cold weather mainly affect that in northern China. Since 1961, during the Spring Festival holiday, the reduction of strong winds and cold days in northern China is conducive to holiday tourism, especially good for ice-snow tourism. In the eastern part of South China, most parts of Yunnan and southern Sichuan, the number of human comfort days has clearly increased while the number of rainy days has decreased, so the climate conditions for winter resort have been improved. Overall, the climate conditions for winter resort and ice-snow tourism during the Spring Festival holiday have shown good trends obviously, which is important for transforming climate resources into tourism economy and promoting the development of featured tourism in various regions.
China’s Spring Festival is usually between 20 January and 26 February every year. The Spring Festival holiday is the golden week of tourism, bringing high tourism flow. The Spring Festival tourism shows climate-driven characteristics. In this paper, human comfort index and trend analysis method are used to analyze the spatial and temporal characteristics of favorable and unfavorable tourism climate conditions during the Spring Festival holiday in China. The results show that during the Spring Festival holiday from 1991 to 2020, there is a significant north-south difference for temperature and precipitation in China. The average temperature in most areas south of the Yangtze River (Jiangnan) is above 5℃, while that in most parts of Heilongjiang and northeastern Inner Mongolia is below -15℃. The precipitation is mainly concentrated in Jiangnan and the central eastern part of South China. The number of human comfort days is more than 10 days in most parts of South China, Yunnan, and southern Sichuan, beneficial for winter resort. The number of snow cover days is more than 15 days in the majority of Northeast China, central and northeastern Inner Mongolia, and northern Xinjiang, which is conducive to ice-snow tourism. Precipitation and fog mainly affect tourism in southern China, while strong winds and cold weather mainly affect that in northern China. Since 1961, during the Spring Festival holiday, the reduction of strong winds and cold days in northern China is conducive to holiday tourism, especially good for ice-snow tourism. In the eastern part of South China, most parts of Yunnan and southern Sichuan, the number of human comfort days has clearly increased while the number of rainy days has decreased, so the climate conditions for winter resort have been improved. Overall, the climate conditions for winter resort and ice-snow tourism during the Spring Festival holiday have shown good trends obviously, which is important for transforming climate resources into tourism economy and promoting the development of featured tourism in various regions.
2026, 52(1):105-118.
DOI: 10.7519/j.issn.1000-0526.2025.120901
Abstract:
During the summer of 2025, the rainfall belt in the central and eastern regions of China was mainly situated in the northern part. Precipitation across north-central North China, central and southern Inner Mongolia, and northern Shaanxi exceeded the climatological mean amount by 50% to 200%, result-ing in severe flooding and related disasters. The rainy season in eastern China exhibited a delayed onset, followed by an early withdrawal. In North China, the onset timing, duration, and accumulated precipita-tion of the rainy season all broke historical records. The excessive precipitation was primarily driven by the pronounced northward displacement of western Pacific subtropical high (WPSH) and the more strengthened East Asian summer monsoon. In addition, intraseasonal variations in the East Asian atmospheric circulation substantially modulated the spatial pattern of monthly precipitation anomalies. Among these influences, anomalous Madden-Julian oscillation (MJO) activity served as a key regulator of intraseasonal circulation variability. In June, frequent Northeast cold vortex activity, combined with a stronger and northward-migrating WPSH, triggered an earlier onset and prolonged duration of the Meiyu season in the Yangtze River and Huaihe River (Jianghuai) Basin, leading to significantly above-normal precipitation in the Meiyu region. In July, persistent MJO convection from the Maritime Continent to the western Pacific subtropical region promoted anomalous typhoon genesis and further northward shift of the WPSH over the northwestern Pacific. As a result, the main rainfall belt was located in the northern part of North China to Hetao Region, the southern part of South China and the southeast coast, resulting in severe typhoon rain and floods. In August, the MJO activity was enhanced in the African-Indian Ocean Region, favoring the even stronger, westward-extending and southward-moving WPSH, further increasing the rainfall amount in the areas north of the Yangtze River Basin.
During the summer of 2025, the rainfall belt in the central and eastern regions of China was mainly situated in the northern part. Precipitation across north-central North China, central and southern Inner Mongolia, and northern Shaanxi exceeded the climatological mean amount by 50% to 200%, result-ing in severe flooding and related disasters. The rainy season in eastern China exhibited a delayed onset, followed by an early withdrawal. In North China, the onset timing, duration, and accumulated precipita-tion of the rainy season all broke historical records. The excessive precipitation was primarily driven by the pronounced northward displacement of western Pacific subtropical high (WPSH) and the more strengthened East Asian summer monsoon. In addition, intraseasonal variations in the East Asian atmospheric circulation substantially modulated the spatial pattern of monthly precipitation anomalies. Among these influences, anomalous Madden-Julian oscillation (MJO) activity served as a key regulator of intraseasonal circulation variability. In June, frequent Northeast cold vortex activity, combined with a stronger and northward-migrating WPSH, triggered an earlier onset and prolonged duration of the Meiyu season in the Yangtze River and Huaihe River (Jianghuai) Basin, leading to significantly above-normal precipitation in the Meiyu region. In July, persistent MJO convection from the Maritime Continent to the western Pacific subtropical region promoted anomalous typhoon genesis and further northward shift of the WPSH over the northwestern Pacific. As a result, the main rainfall belt was located in the northern part of North China to Hetao Region, the southern part of South China and the southeast coast, resulting in severe typhoon rain and floods. In August, the MJO activity was enhanced in the African-Indian Ocean Region, favoring the even stronger, westward-extending and southward-moving WPSH, further increasing the rainfall amount in the areas north of the Yangtze River Basin.
2026, 52(1):119-128.
DOI: 10.7519/j.issn.1000-0526.2025.121201
Abstract:
The main characteristics of the general atmospheric circulation in October 2025 are as follows. The polar vortex was distributed in a monopole pattern, biased towards the Western Hemisphere side. The mid-high latitude circulation in the Northern Hemisphere presented a four-wave distribution, while in the Eurasian Region it was in a “two troughs and one ridge” pattern. The western Pacific subtropical high was stronger and the location was more westward and northward. There were frequent tropical low value system activities in the ocean area to the east of the Philippines. In October, the monthly mean temperature was 11.0℃， 0.4℃ higher than the average (10.6℃) of the same period in previous years. The monthly average precipitation was 54.4 mm, 52.8% more than the normal (35.6 mm). During this month, there were four cold air processes, five major precipitation processes, and two typhoons affecting China. Typhoon Matmo brought severe precipitation and strong winds to South China. In addition, a strong cold air process from 16 to 19 October caused a significant drop in temperature across central and eastern parts of China.
The main characteristics of the general atmospheric circulation in October 2025 are as follows. The polar vortex was distributed in a monopole pattern, biased towards the Western Hemisphere side. The mid-high latitude circulation in the Northern Hemisphere presented a four-wave distribution, while in the Eurasian Region it was in a “two troughs and one ridge” pattern. The western Pacific subtropical high was stronger and the location was more westward and northward. There were frequent tropical low value system activities in the ocean area to the east of the Philippines. In October, the monthly mean temperature was 11.0℃， 0.4℃ higher than the average (10.6℃) of the same period in previous years. The monthly average precipitation was 54.4 mm, 52.8% more than the normal (35.6 mm). During this month, there were four cold air processes, five major precipitation processes, and two typhoons affecting China. Typhoon Matmo brought severe precipitation and strong winds to South China. In addition, a strong cold air process from 16 to 19 October caused a significant drop in temperature across central and eastern parts of China.
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ISSN:1000-0526 CN:11-2282/P