ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 49,Issue 3,2023 Table of Contents
2023, 49(3):257-266.
DOI: 10.7519/j.issn.1000-0526.2023.022301
Abstract:
Climate change induced by human activities has already been affecting many weather, climate and water extremes in every region across the globe. Every additional increment of global warming will lead to larger changes in extreme events. If there is no action on global carbon neutralization, further increases in the intensity and frequency of hot extremes and decreases in the intensity and frequency of cold extremes will occur throughout the 21st century around the world. And the intensity and frequency of heavy precipitation as well as agricultural and ecological drought in some regions will also undergo a significant increase. Today’s children and future generations are more vulnerable to the risk of future climate change and extremes. They are projected to experience nearly four-fold increase in extreme weather, climate and water events by the end of this century even at 1.5℃ of warming relative to pre-industrial levels. In view of the increasingly severe risk of climate change and extreme events, it is urgent to actively pursue the carbon peaking and carbon neutrality goals and strong reductions in the emissions of methane and other greenhouse gases. At the same time, it is urgent to formulate policies and measures related to disaster prevention and mitigation, and promote the construction of extreme event monitoring and early warning system and resilience. Additionally, it cannot be neglected to enhance the prevention of compound extreme events and small probability-high impact events to ensure the well-being and sustainable development of future generations.
Climate change induced by human activities has already been affecting many weather, climate and water extremes in every region across the globe. Every additional increment of global warming will lead to larger changes in extreme events. If there is no action on global carbon neutralization, further increases in the intensity and frequency of hot extremes and decreases in the intensity and frequency of cold extremes will occur throughout the 21st century around the world. And the intensity and frequency of heavy precipitation as well as agricultural and ecological drought in some regions will also undergo a significant increase. Today’s children and future generations are more vulnerable to the risk of future climate change and extremes. They are projected to experience nearly four-fold increase in extreme weather, climate and water events by the end of this century even at 1.5℃ of warming relative to pre-industrial levels. In view of the increasingly severe risk of climate change and extreme events, it is urgent to actively pursue the carbon peaking and carbon neutrality goals and strong reductions in the emissions of methane and other greenhouse gases. At the same time, it is urgent to formulate policies and measures related to disaster prevention and mitigation, and promote the construction of extreme event monitoring and early warning system and resilience. Additionally, it cannot be neglected to enhance the prevention of compound extreme events and small probability-high impact events to ensure the well-being and sustainable development of future generations.
2023, 49(3):267-278.
DOI: 10.7519/j.issn.1000-0526.2022.071201
Abstract:
The convective characteristics of rainstorms in China are considerable, but the statistical relationship between rainstorms and short-duration heavy rainfall, which is one of the severe convective weather, remains unclear. The characteristics of the contribution of two types of short-duration heavy rainfall (hourly rainfall ≥20 mm and hourly rainfall ≥50 mm, referred to as HR20 and HR50, respectively) to different intensities of rainstorms are obtained by analyzing the hourly rainfall data collected during 1951-2019. The results show that the area of rainstorm with high frequency of short-duration heavy rainfall is not consistent with the area of high frequency days of rainstorms. Short-duration heavy rainfall has the most significant impact on rainstorms over the south part of North China, the Huanghuai Area and the Southwest to South China, where HR20 accounts for more than 50% of the rainstorm days. The south part of North China and the central part of South China have more than 70%, which is the highest. Furthermore, the proportion of short-duration heavy rainfall gradually increases as the intensity of rainstorms enhances, especially the HR50 has increased significantly. More than 60% of the extreme torrential rain days are accompanied by HR50, indicating that the more intense the rainstorm, the more significant the convection. The total precipitation amounts produced by short-duration heavy rainfall contribute most to the rainstorm over regions such as the south part of North China, Huanghuai Area, the east part of Southwest China and South China. The contribution of the short-duration heavy rainfall also increases significantly as the rainstorm intensity enhances, especially that of HR50 increased by more than 100%. In areas such as Jianghuai Area and Jiangnan, the contribution of the short-duration heavy rainfall is smaller, and its increase is relatively insignificant with the increase of the intensity of the rainstorm. In addition, when there is a short-duration heavy rainfall (HR20), the amounts of torrential rain and sever torrential rain increase by an average of 20% and 40% respectively compared to those with no short-duration heavy rainfall accompanied. This further demonstrates the convective characteristics of rainstorms in China.
The convective characteristics of rainstorms in China are considerable, but the statistical relationship between rainstorms and short-duration heavy rainfall, which is one of the severe convective weather, remains unclear. The characteristics of the contribution of two types of short-duration heavy rainfall (hourly rainfall ≥20 mm and hourly rainfall ≥50 mm, referred to as HR20 and HR50, respectively) to different intensities of rainstorms are obtained by analyzing the hourly rainfall data collected during 1951-2019. The results show that the area of rainstorm with high frequency of short-duration heavy rainfall is not consistent with the area of high frequency days of rainstorms. Short-duration heavy rainfall has the most significant impact on rainstorms over the south part of North China, the Huanghuai Area and the Southwest to South China, where HR20 accounts for more than 50% of the rainstorm days. The south part of North China and the central part of South China have more than 70%, which is the highest. Furthermore, the proportion of short-duration heavy rainfall gradually increases as the intensity of rainstorms enhances, especially the HR50 has increased significantly. More than 60% of the extreme torrential rain days are accompanied by HR50, indicating that the more intense the rainstorm, the more significant the convection. The total precipitation amounts produced by short-duration heavy rainfall contribute most to the rainstorm over regions such as the south part of North China, Huanghuai Area, the east part of Southwest China and South China. The contribution of the short-duration heavy rainfall also increases significantly as the rainstorm intensity enhances, especially that of HR50 increased by more than 100%. In areas such as Jianghuai Area and Jiangnan, the contribution of the short-duration heavy rainfall is smaller, and its increase is relatively insignificant with the increase of the intensity of the rainstorm. In addition, when there is a short-duration heavy rainfall (HR20), the amounts of torrential rain and sever torrential rain increase by an average of 20% and 40% respectively compared to those with no short-duration heavy rainfall accompanied. This further demonstrates the convective characteristics of rainstorms in China.
2023, 49(3):279-290.
DOI: 10.7519/j.issn.1000-0526.2022.061001
Abstract:
The Chinese new generation of Doppler weather radar (CINRAD) has the advantages of high spatio-temporal resolution. It can observe the change process of precipitation intensity and the real-time movement of precipitation area in detail, and also can effectively monitor disastrous weather events. In this paper, the spatio-temporal distribution characteristics of summer precipitation in South China are investigated based on Doppler multiradar mosaic data in South China from 2017 to 2020. The results show that the frequency of summer precipitation in South China is dominated by stratiform precipitation. In most parts of South China, the frequency of stratiform precipitation is more than 85%, while the frequency of convective precipitation only accounts for about 14%. The peak reflectivity and the frequency of convective precipitation in Guangdong are higher than those in Guangxi and Hainan. Both the peak reflectivity and precipitation frequency show strong diurnal variation with local solar radiation, and also exhibits discernible regional differences. The reflectivity peak is roughly similar to the spatial distribution of convective precipitation, and the frequencies along the coast are higher than those in the inland region. Stratiform precipitation occurs most frequently in the inland region than along the coast. The frequency of stratiform precipitation is mostly concentrated at night with peaks seen in the morning. The peak reflectivity and convective precipitation are mostly concentrated in the daytime, the high-value region expands from the western coast to the inland and eastern coast as time changes, reaching the peak between afternoon and night. The diurnal variation of convective precipitation exhibits different bimodal patterns in coastal and inland region. A major peak appears in the morning and a secondary peak in the late afternoon, and the morning peak in central Guangdong is significantly lower than the afternoon peak.
The Chinese new generation of Doppler weather radar (CINRAD) has the advantages of high spatio-temporal resolution. It can observe the change process of precipitation intensity and the real-time movement of precipitation area in detail, and also can effectively monitor disastrous weather events. In this paper, the spatio-temporal distribution characteristics of summer precipitation in South China are investigated based on Doppler multiradar mosaic data in South China from 2017 to 2020. The results show that the frequency of summer precipitation in South China is dominated by stratiform precipitation. In most parts of South China, the frequency of stratiform precipitation is more than 85%, while the frequency of convective precipitation only accounts for about 14%. The peak reflectivity and the frequency of convective precipitation in Guangdong are higher than those in Guangxi and Hainan. Both the peak reflectivity and precipitation frequency show strong diurnal variation with local solar radiation, and also exhibits discernible regional differences. The reflectivity peak is roughly similar to the spatial distribution of convective precipitation, and the frequencies along the coast are higher than those in the inland region. Stratiform precipitation occurs most frequently in the inland region than along the coast. The frequency of stratiform precipitation is mostly concentrated at night with peaks seen in the morning. The peak reflectivity and convective precipitation are mostly concentrated in the daytime, the high-value region expands from the western coast to the inland and eastern coast as time changes, reaching the peak between afternoon and night. The diurnal variation of convective precipitation exhibits different bimodal patterns in coastal and inland region. A major peak appears in the morning and a secondary peak in the late afternoon, and the morning peak in central Guangdong is significantly lower than the afternoon peak.
2023, 49(3):291-303.
DOI: 10.7519/j.issn.1000-0526.2022.071801
Abstract:
Based on surface automatic observation data, Doppler radar data, Himawari-8 satellite data and ERA-5 high resolution reanalysis data, this paper analyzes the synoptic background, environmental conditions and evolution characteristics of mesoscale systems and convective storms of the EF2 tornado event that occurred in Gaoyou County, Jiangsu Province on 12 June 2020. The monitoring and early warning experience and forecasting thoughts are summarized as well. The results are as follows. The Gaoyou tornado occurred during the first rainstorm process at the beginning of Meiyu in Jiangsu Province. The synoptic condition was partly similar to that of the Funing EF4 tornado on 23 June 2016. The Gaoyou tornado and the Funing tornado both showed up typical characteristics of Meiyu front tornado. The convective system producing tornado appeared in front of 500 hPa westerly trough, in the southwest quadrant of 850 hPa vortex and left side of low-level jet, with strong convective instability energy and low lifting condensation level. But CAPE and vertical wind shear of the Gaoyou tornado were weaker than in the Funing tornado process. The tornado occurred at the top of a moving meso-β scale depression, which was located in the convergence area of surface divergence and the surface temperature warm tongue. The convergence near the center of storm strengthened sharply, which might indicate the tornado. The storm generating the tornado had a long lifetime. Continuous tornado vortex signature (TVS) was recognized 60 minutes ahead. The storm passing through Gaoyou Lake was enhanced. Mesocyclones (M) appeared and coexisted with TVS within 8 radar volume scans. Before the tornado reached the ground, the bottom height of TVS decreased but shear increased significantly. The diameter of the mesocyclone decreased vertically in an inverted trapezoidal structure. The rotation speed shear strengthened, getting to the minimum height. All these features give good indications for the early warning of tornadoes. Based on synoptic-scale system model, meso- and small-scale environmental physical indexes and convective scale storm characteristic evolutions, Jiangsu meteorological departments had a progressive early warning, achieving a successful practice.
Based on surface automatic observation data, Doppler radar data, Himawari-8 satellite data and ERA-5 high resolution reanalysis data, this paper analyzes the synoptic background, environmental conditions and evolution characteristics of mesoscale systems and convective storms of the EF2 tornado event that occurred in Gaoyou County, Jiangsu Province on 12 June 2020. The monitoring and early warning experience and forecasting thoughts are summarized as well. The results are as follows. The Gaoyou tornado occurred during the first rainstorm process at the beginning of Meiyu in Jiangsu Province. The synoptic condition was partly similar to that of the Funing EF4 tornado on 23 June 2016. The Gaoyou tornado and the Funing tornado both showed up typical characteristics of Meiyu front tornado. The convective system producing tornado appeared in front of 500 hPa westerly trough, in the southwest quadrant of 850 hPa vortex and left side of low-level jet, with strong convective instability energy and low lifting condensation level. But CAPE and vertical wind shear of the Gaoyou tornado were weaker than in the Funing tornado process. The tornado occurred at the top of a moving meso-β scale depression, which was located in the convergence area of surface divergence and the surface temperature warm tongue. The convergence near the center of storm strengthened sharply, which might indicate the tornado. The storm generating the tornado had a long lifetime. Continuous tornado vortex signature (TVS) was recognized 60 minutes ahead. The storm passing through Gaoyou Lake was enhanced. Mesocyclones (M) appeared and coexisted with TVS within 8 radar volume scans. Before the tornado reached the ground, the bottom height of TVS decreased but shear increased significantly. The diameter of the mesocyclone decreased vertically in an inverted trapezoidal structure. The rotation speed shear strengthened, getting to the minimum height. All these features give good indications for the early warning of tornadoes. Based on synoptic-scale system model, meso- and small-scale environmental physical indexes and convective scale storm characteristic evolutions, Jiangsu meteorological departments had a progressive early warning, achieving a successful practice.
2023, 49(3):304-317.
DOI: 10.7519/j.issn.1000-0526.2022.080102
Abstract:
A rare regional severe convection process of Guangxi occurred in 24-25 January 2020, which was accompanied by the maximal range hail process since 2000. The abnormal development and eastward of the southern branch trough (SBT) were the disturbance backgrounds that provided necessary thermal, dynamic and water vapor conditions. Based on conventional observation data, FY-2G satellite data, NCEP/NCAR and ERA5 reanalysis data, the SBT inducing the regional severe convection process is analyzed from the perspective of energy conversion. The results show that the mid-latitude and subtropical westerly jets were stronger than those in the same peried in history during the whole process, which were conducive to the upstream disturbance spreading. There were two active Rossby wave trains over the northern and southern Eurasia respectively. The southern subtropical westerly jet Rossby wave originated from the Mediterranean Sea played a major role in regulating the SBT. The Rossby wave energy dispersed along the jet stream and converged in SBT region, promoting the development and eastward of SBT. The northern one originated from the North Atlantic blocking played a synergistic role, promoting the development of the Urals cold trough and its merger with the Middle East trough, thereby enhancing the propagation of the southern one and further enhancing the SBT. The conversion from synoptic-scale available potential energy and the transport of kinetic energy from background field to synoptic-scale were the main contributions of synoptic-scale disturbance of SBT. The advection transport of kinetic energy redistributed the obtained synoptic-scale kinetic energy in space and thus maintained the stable development of SBT and moving eastward. Under the above background, the downscaled kinetic energy cascade from synoptic-scale to convective scale became the main energy source of regional severe convective, and the stable conversion of convective scale available potential energy to kinetic energy promoted the occurrence and development of the convective disturbances in the middle and low troposphere.
A rare regional severe convection process of Guangxi occurred in 24-25 January 2020, which was accompanied by the maximal range hail process since 2000. The abnormal development and eastward of the southern branch trough (SBT) were the disturbance backgrounds that provided necessary thermal, dynamic and water vapor conditions. Based on conventional observation data, FY-2G satellite data, NCEP/NCAR and ERA5 reanalysis data, the SBT inducing the regional severe convection process is analyzed from the perspective of energy conversion. The results show that the mid-latitude and subtropical westerly jets were stronger than those in the same peried in history during the whole process, which were conducive to the upstream disturbance spreading. There were two active Rossby wave trains over the northern and southern Eurasia respectively. The southern subtropical westerly jet Rossby wave originated from the Mediterranean Sea played a major role in regulating the SBT. The Rossby wave energy dispersed along the jet stream and converged in SBT region, promoting the development and eastward of SBT. The northern one originated from the North Atlantic blocking played a synergistic role, promoting the development of the Urals cold trough and its merger with the Middle East trough, thereby enhancing the propagation of the southern one and further enhancing the SBT. The conversion from synoptic-scale available potential energy and the transport of kinetic energy from background field to synoptic-scale were the main contributions of synoptic-scale disturbance of SBT. The advection transport of kinetic energy redistributed the obtained synoptic-scale kinetic energy in space and thus maintained the stable development of SBT and moving eastward. Under the above background, the downscaled kinetic energy cascade from synoptic-scale to convective scale became the main energy source of regional severe convective, and the stable conversion of convective scale available potential energy to kinetic energy promoted the occurrence and development of the convective disturbances in the middle and low troposphere.
2023, 49(3):318-326.
DOI: 10.7519/j.issn.1000-0526.2023.020601
Abstract:
According to the requirements of weather, climate and ecological environment monitoring for land surface temperature (LST) at high spatial resolution and all-weather, this paper develops the spatial downscaling algorithm of LST from geostationary meteorological satellite observation and the reconstruction algorithm of LST under cloud from polar orbiting meteorological satellite observation respectively. The LST spatial downscaling model of geostationary meteorological satellite makes full use of the advantages of geostationary meteorological satellite observation in both high time-frequency and multi-spectrum. A nonlinear statistical regression model is established based on the daily variation characteristics of LST and brightness temperature of relevant channels of the same remote sensor of Fengyun-4A (FY-4A). And the underlying surface types are also taken into consideration. The method is applied to the LST downscaling of FY-4A AGRI (advanced geosynchronous radiation imager). The results show that the developed downscaling model can not only downscale the LST of FY-4A AGRI from 4 km to 2 km, but also maintain the accuracy of LST before downscaling, and the maximum RMSE of LST before and after downscaling is 1.35 K. For the LST reconstruction under cloud of polar orbiting meteorological satellite, the DINEOF model is developed, and the secondary correction of the results is carried out based on Land-Use data (LU), so as to realize the all-weather acquisition of polar orbiting meteorological satellite LST. The method is applied to polar orbiting meteorological satellite FY-3D medium mesolution spectral imager LST, and the results are as expected.
According to the requirements of weather, climate and ecological environment monitoring for land surface temperature (LST) at high spatial resolution and all-weather, this paper develops the spatial downscaling algorithm of LST from geostationary meteorological satellite observation and the reconstruction algorithm of LST under cloud from polar orbiting meteorological satellite observation respectively. The LST spatial downscaling model of geostationary meteorological satellite makes full use of the advantages of geostationary meteorological satellite observation in both high time-frequency and multi-spectrum. A nonlinear statistical regression model is established based on the daily variation characteristics of LST and brightness temperature of relevant channels of the same remote sensor of Fengyun-4A (FY-4A). And the underlying surface types are also taken into consideration. The method is applied to the LST downscaling of FY-4A AGRI (advanced geosynchronous radiation imager). The results show that the developed downscaling model can not only downscale the LST of FY-4A AGRI from 4 km to 2 km, but also maintain the accuracy of LST before downscaling, and the maximum RMSE of LST before and after downscaling is 1.35 K. For the LST reconstruction under cloud of polar orbiting meteorological satellite, the DINEOF model is developed, and the secondary correction of the results is carried out based on Land-Use data (LU), so as to realize the all-weather acquisition of polar orbiting meteorological satellite LST. The method is applied to polar orbiting meteorological satellite FY-3D medium mesolution spectral imager LST, and the results are as expected.
ZHU Shizhen
,
ZHANG Zhaoyi
,
WU Shixiao
,
YANG Jun
,
WANG Zhaoyu
,
SHI Chun’e
,
HU Hanfeng
,
ZHANG Hao
,
NI Ting
,
QIU Yujun
,
LU Chunsong
2023, 49(3):327-339.
DOI: 10.7519/j.issn.1000-0526.2022.021001
Abstract:
Using the fog droplet spectrum and visibility data of two dense fog processes in 12-13 January 2019 in Shouxian, Anhui Province, the microphysical characteristics (such as the size distribution, droplet number concentration, liquid water content, average diameter, spectral width, etc.) and the correlations among microphysical properties (number concentration, liquid water content, average diameter) in the different stages of fog are analyzed. The results show that both the fog processes were radiation fog. If the strong inversion structure close to the ground maintains, the water vapor can be restrained in the inversion layer, conducive to the long-term maintenance of dense fog. The formation time of the fog at 20 m was later than that on the surface. In the early stages of formation, development and maturity, the microphysical characteristics of the surface fog were all larger than that at 20 m. At the late stage of maturity, the release of latent heat by condensation and ground heating might increase the intensity of turbulent mixing in the fog, making the fog uniform in the vertical direction. The fog processes at two heights were dominated by nucleation and condensation growth, but the collision-coalescence process also played an important role in the fog on the surface. From the stages of formation, development to maturity, the collision-coalescence processes of the ground fog gradually strengthened. The correlation among the number concentration, water content, and average diameter generally changed from strong positive correlation to weak positive or negative correlation. From the early stage to the late stage of the mature stage, the relationship between average diameter and number concentration of the fog at 20 m height changed from a positive correlation to a negative correlation, which was likely to be related to the factors such as turbulent motion, entrainment mixing, etc.
Using the fog droplet spectrum and visibility data of two dense fog processes in 12-13 January 2019 in Shouxian, Anhui Province, the microphysical characteristics (such as the size distribution, droplet number concentration, liquid water content, average diameter, spectral width, etc.) and the correlations among microphysical properties (number concentration, liquid water content, average diameter) in the different stages of fog are analyzed. The results show that both the fog processes were radiation fog. If the strong inversion structure close to the ground maintains, the water vapor can be restrained in the inversion layer, conducive to the long-term maintenance of dense fog. The formation time of the fog at 20 m was later than that on the surface. In the early stages of formation, development and maturity, the microphysical characteristics of the surface fog were all larger than that at 20 m. At the late stage of maturity, the release of latent heat by condensation and ground heating might increase the intensity of turbulent mixing in the fog, making the fog uniform in the vertical direction. The fog processes at two heights were dominated by nucleation and condensation growth, but the collision-coalescence process also played an important role in the fog on the surface. From the stages of formation, development to maturity, the collision-coalescence processes of the ground fog gradually strengthened. The correlation among the number concentration, water content, and average diameter generally changed from strong positive correlation to weak positive or negative correlation. From the early stage to the late stage of the mature stage, the relationship between average diameter and number concentration of the fog at 20 m height changed from a positive correlation to a negative correlation, which was likely to be related to the factors such as turbulent motion, entrainment mixing, etc.
2023, 49(3):340-350.
DOI: 10.7519/j.issn.1000-0526.2022.080302
Abstract:
To explore the effects of daily mean temperature on bronchitis outpatient visit in Lanzhou, we collected the data on bronchitis outpatient visit, meteorology and atmospheric pollutants during 2013-2019 from three general hospitals in Lanzhou. In this paper, we construct a distribution lag non-linear model to analyze the relationship between the temperature and the daily risk of bronchitis outpatient visit. The stratified analysis is performed according to the division of ages and gender groups. The effect of daily mean temperature on bronchitis outpatient visit is non-linear and lagging. The hazard effects of low temperature (-5.0℃), and high temperature (25.4℃) are the largest on that very day, and then get weakened gradually with the lag days. The hazard effect of low temperature lasts for 13 days (lag 1-13 d), and the hazard effect of high temperature lasts 19 days. The cold effect has a greater harmful effect and duration than the heat effect. When the temperature is set to -5.0℃ and 25.4℃, the maximal cumulative lag effect appears on lag 0-14 d, and lag 0-21 d, respectively, the RR values are 2.832 (95%CI: 2.411-3.326) and 1.070 (95%CI: 1.054-1.086). The risk of bronchial outpatient visit caused by low temperature, and high temperature is greater for men than for women, with a maximum cumulative relative risk of 3.089 (95%CI: 2.601-3.669) and 1.085 (95%CI: 1.067-1.104). The risk of outpatient visits for children aged 0-14 is significantly higher than that of other age groups at low temperature, and the peak RR appears on lag 0-14 d, with the value of 3.191 (95%CI: 2.654-3.837). When the temperature is at 25.4℃, the maximum value occurs on lag 0-21 d, and the RR value is 1.089 (95%CI: 1.070-1.109). Both high temperature and low temperature imdrove the bronchitis outpatient visit risk. The harmful effect and duration of low temperature are greater than that of high temperature, and children aged 0-14 are more sensitive to low temperature.
To explore the effects of daily mean temperature on bronchitis outpatient visit in Lanzhou, we collected the data on bronchitis outpatient visit, meteorology and atmospheric pollutants during 2013-2019 from three general hospitals in Lanzhou. In this paper, we construct a distribution lag non-linear model to analyze the relationship between the temperature and the daily risk of bronchitis outpatient visit. The stratified analysis is performed according to the division of ages and gender groups. The effect of daily mean temperature on bronchitis outpatient visit is non-linear and lagging. The hazard effects of low temperature (-5.0℃), and high temperature (25.4℃) are the largest on that very day, and then get weakened gradually with the lag days. The hazard effect of low temperature lasts for 13 days (lag 1-13 d), and the hazard effect of high temperature lasts 19 days. The cold effect has a greater harmful effect and duration than the heat effect. When the temperature is set to -5.0℃ and 25.4℃, the maximal cumulative lag effect appears on lag 0-14 d, and lag 0-21 d, respectively, the RR values are 2.832 (95%CI: 2.411-3.326) and 1.070 (95%CI: 1.054-1.086). The risk of bronchial outpatient visit caused by low temperature, and high temperature is greater for men than for women, with a maximum cumulative relative risk of 3.089 (95%CI: 2.601-3.669) and 1.085 (95%CI: 1.067-1.104). The risk of outpatient visits for children aged 0-14 is significantly higher than that of other age groups at low temperature, and the peak RR appears on lag 0-14 d, with the value of 3.191 (95%CI: 2.654-3.837). When the temperature is at 25.4℃, the maximum value occurs on lag 0-21 d, and the RR value is 1.089 (95%CI: 1.070-1.109). Both high temperature and low temperature imdrove the bronchitis outpatient visit risk. The harmful effect and duration of low temperature are greater than that of high temperature, and children aged 0-14 are more sensitive to low temperature.
LIU Couhua
,
DAI Kan
,
LIN Jian
,
WEI Qing
,
LI Nina
,
WANG Baoli
,
TANG Buxing
,
GUO Yunqian
,
ZHU Wenjian
,
TANG Jian
,
ZENG Xiaoqing
2023, 49(3):351-364.
DOI: 10.7519/j.issn.1000-0526.2022.050902
Abstract:
In order to evaluate the contribution of each process from numerical forecast, objective method to subjective forecast products to the accuracy of weather forecast, the Meteorological Evaluation Program Library (MetEva) is developed. Aiming at the whole process coverage of the verification algorithm and the comparability of the evaluation results, MetEva adopts a hierarchical architecture including basic layer and functional layer, and designs a modular inspection and calculation process based on a unified data structure. The program library provides over 400 functions around the steps of data reading, data merging and matching, sample selection, sample grouping, inspection calculation and result output for verification. MetEva provides 54 evaluation methods in five categories, covering most of methods recommended by the World Meteorological Organization and algorithms in domestic specifications. By using matrix calculation in each module and providing parallel scheme for verification algorithms, the operation efficiency is improved. Taking the evaluation of temperature and precipitation forecast as an example, this paper briefly explains the application MetEva, and shows its value in verification. The program library has been released as open source, which can effectively support meteorological departments at all levels to carry out the evaluation of the whole process of weather forecast.
In order to evaluate the contribution of each process from numerical forecast, objective method to subjective forecast products to the accuracy of weather forecast, the Meteorological Evaluation Program Library (MetEva) is developed. Aiming at the whole process coverage of the verification algorithm and the comparability of the evaluation results, MetEva adopts a hierarchical architecture including basic layer and functional layer, and designs a modular inspection and calculation process based on a unified data structure. The program library provides over 400 functions around the steps of data reading, data merging and matching, sample selection, sample grouping, inspection calculation and result output for verification. MetEva provides 54 evaluation methods in five categories, covering most of methods recommended by the World Meteorological Organization and algorithms in domestic specifications. By using matrix calculation in each module and providing parallel scheme for verification algorithms, the operation efficiency is improved. Taking the evaluation of temperature and precipitation forecast as an example, this paper briefly explains the application MetEva, and shows its value in verification. The program library has been released as open source, which can effectively support meteorological departments at all levels to carry out the evaluation of the whole process of weather forecast.
2023, 49(3):365-378.
DOI: 10.7519/j.issn.1000-0526.2023.012901
Abstract:
The main characteristics of climate in summer 2022 were accurately predicted by National Climate Centre (NCC), including “the overall climate condition is unfavorable, with regional and phased floods and droughts, significantly uneven spatial distribution of rainfall, and the main anomalous-rainfall belt located in northern China”. The position of main anomalous-rainfall belt and spatial distribution of floods and droughts in China was well predicted in advance at the end of March 2022. The prediction of seasonal progress of East Asian summer monsoon and rainy season was also consistent with observations. For example, the onset date of South China Sea summer monsoon was in the 3rd pentad of May, earlier and less Meiyu occurred over the middle and lower reaches of the Yangtze River, the rainy season of North China started earlier than the climatology with above-normal precipitation, etc. The predicted less-generated tropical cyclones over western North Pacific and high probability of northward-moving typhoons in the summer were basically in line with the observations. The hot summer in 2022 and the spatial pattern of temperature anomalies in China were well captured. The prediction of “the temperature in most part of central and eastern China and Xinjiang is above normal, with more high temperature days and heat waves” was in good agreement with the observations. The main deficiency of the prediction was the underestimation of the spatial coverage and extremity of the record-breaking heat wave and drought in the Middle and lower reaches of the Yangtze River and the Sichuan and Chongqing regions. The prediction of flood season in 2022 was mainly based on the impact of multiyear La Ni〖AKn~D〗a event and the tropical Indian Ocean dipole mode on the summer monsoon circulation over East Asia. The intensity of western Pacific subtropical high was abnormally strong with northward displacement of the ridge line. With the intensified East Asian summer monsoon, and active northeast cold vortex in early summer, the above factors synergistically contributed to the formation of main anomalous-rainfall belt in Northeast China, North China, and eastern part of Northwest China.
The main characteristics of climate in summer 2022 were accurately predicted by National Climate Centre (NCC), including “the overall climate condition is unfavorable, with regional and phased floods and droughts, significantly uneven spatial distribution of rainfall, and the main anomalous-rainfall belt located in northern China”. The position of main anomalous-rainfall belt and spatial distribution of floods and droughts in China was well predicted in advance at the end of March 2022. The prediction of seasonal progress of East Asian summer monsoon and rainy season was also consistent with observations. For example, the onset date of South China Sea summer monsoon was in the 3rd pentad of May, earlier and less Meiyu occurred over the middle and lower reaches of the Yangtze River, the rainy season of North China started earlier than the climatology with above-normal precipitation, etc. The predicted less-generated tropical cyclones over western North Pacific and high probability of northward-moving typhoons in the summer were basically in line with the observations. The hot summer in 2022 and the spatial pattern of temperature anomalies in China were well captured. The prediction of “the temperature in most part of central and eastern China and Xinjiang is above normal, with more high temperature days and heat waves” was in good agreement with the observations. The main deficiency of the prediction was the underestimation of the spatial coverage and extremity of the record-breaking heat wave and drought in the Middle and lower reaches of the Yangtze River and the Sichuan and Chongqing regions. The prediction of flood season in 2022 was mainly based on the impact of multiyear La Ni〖AKn~D〗a event and the tropical Indian Ocean dipole mode on the summer monsoon circulation over East Asia. The intensity of western Pacific subtropical high was abnormally strong with northward displacement of the ridge line. With the intensified East Asian summer monsoon, and active northeast cold vortex in early summer, the above factors synergistically contributed to the formation of main anomalous-rainfall belt in Northeast China, North China, and eastern part of Northwest China.
2023, 49(3):379-384.
DOI: 10.7519/j.issn.1000-0526.2023.021601
Abstract:
The main characteristics of the general atmospheric circulation in December 2022 are as follow. There were two polar vortex centers in the Northern Hemisphere. The East Asian trough was stronger than in the same period of normal years, which was conducive to the outbreak of cold airs. The southern branch trough was weaker and the western Pacific subtropical high was located more eastward than the normal, which was not good for the formation of precipitation. The monthly mean precipitation over China was 7.5 mm, which is less than normal (11.9 mm) by 37%. The monthly average temperature was -4.2℃, 1.2℃ lower than the normal (3.0℃). During this month, cold airs were very active and there occurred four nationwide cold wave processes, so the atmospheric diffusion conditions were good in most regions of China. The sanddust storm process from 11 to 13 December was stronger and occurred later than in the December of normal years.
The main characteristics of the general atmospheric circulation in December 2022 are as follow. There were two polar vortex centers in the Northern Hemisphere. The East Asian trough was stronger than in the same period of normal years, which was conducive to the outbreak of cold airs. The southern branch trough was weaker and the western Pacific subtropical high was located more eastward than the normal, which was not good for the formation of precipitation. The monthly mean precipitation over China was 7.5 mm, which is less than normal (11.9 mm) by 37%. The monthly average temperature was -4.2℃, 1.2℃ lower than the normal (3.0℃). During this month, cold airs were very active and there occurred four nationwide cold wave processes, so the atmospheric diffusion conditions were good in most regions of China. The sanddust storm process from 11 to 13 December was stronger and occurred later than in the December of normal years.
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ISSN:1000-0526 CN:11-2282/P