Pub Date : 2023-09-01DOI: 10.3724/j.1006-8775.2023.022
Lan ZHANG, Peng-fei REN, Dao-sheng XU, Huai-yu LI, Yu-fei ZHANG
: This study evaluated the forecast skill of CMA-GD 3 km and CMA-GD 1 km with hourly Rapid Update Cycle (RUC) for five monsoon precipitation events in South China from 2018 to 2020, using the fraction skill score (FSS) of the neighborhood spatial verification method. The results revealed that, among the 24-lead-hour forecasts in CMA-GD 3 km, the FSS for the 0.1 mm precipitation threshold increased linearly with the lead time from 3 to 1 hour, while there was no significant improvement in other lead times. For the 5 mm precipitation threshold, the forecast skill was highest for the latest 1-hour lead time, while the FSS showed slight variation between lead times of 24 hours and 8 hours. The FSS for 10 mm and 20 mm precipitation thresholds were similar to that of 5 mm, with the difference that the best score occurred at the 2-hour lead time. Among the 6-lead-hour forecasts in CMA-GD 1 km, the forecasts of the latest 1-hour lead time were the best choices for four precipitation thresholds. When comparing CMA-GD 3 km and CMA-GD 1 km, it was found that CMA-GD 3 km had better skill for forecasts of 0.1 mm and 5 mm precipitation at 2-hour and 1-hour lead times, while CMA-GD 1 km had better skill for all other forecasts, including the forecast of 20 mm precipitation nearly all lead hours (including 3-to 6-hour, and 1-hour lead times). The results suggest that the increased resolution of the model may be beneficial for precipitation forecasts in South China, especially for short-duration heavy precipitation over a longer lead hours. However, the limited sample size of this study calls for further evaluation using more cases to validate the results′ generality.
{"title":"FSS-based Evaluation on Monsoon Precipitation Forecasts in South China from Regional Models with Different Resolution","authors":"Lan ZHANG, Peng-fei REN, Dao-sheng XU, Huai-yu LI, Yu-fei ZHANG","doi":"10.3724/j.1006-8775.2023.022","DOIUrl":"https://doi.org/10.3724/j.1006-8775.2023.022","url":null,"abstract":": This study evaluated the forecast skill of CMA-GD 3 km and CMA-GD 1 km with hourly Rapid Update Cycle (RUC) for five monsoon precipitation events in South China from 2018 to 2020, using the fraction skill score (FSS) of the neighborhood spatial verification method. The results revealed that, among the 24-lead-hour forecasts in CMA-GD 3 km, the FSS for the 0.1 mm precipitation threshold increased linearly with the lead time from 3 to 1 hour, while there was no significant improvement in other lead times. For the 5 mm precipitation threshold, the forecast skill was highest for the latest 1-hour lead time, while the FSS showed slight variation between lead times of 24 hours and 8 hours. The FSS for 10 mm and 20 mm precipitation thresholds were similar to that of 5 mm, with the difference that the best score occurred at the 2-hour lead time. Among the 6-lead-hour forecasts in CMA-GD 1 km, the forecasts of the latest 1-hour lead time were the best choices for four precipitation thresholds. When comparing CMA-GD 3 km and CMA-GD 1 km, it was found that CMA-GD 3 km had better skill for forecasts of 0.1 mm and 5 mm precipitation at 2-hour and 1-hour lead times, while CMA-GD 1 km had better skill for all other forecasts, including the forecast of 20 mm precipitation nearly all lead hours (including 3-to 6-hour, and 1-hour lead times). The results suggest that the increased resolution of the model may be beneficial for precipitation forecasts in South China, especially for short-duration heavy precipitation over a longer lead hours. However, the limited sample size of this study calls for further evaluation using more cases to validate the results′ generality.","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Impacts of Increasing Model Resolutions and Shortening Forecast Lead Times on QPFs in South China During the Rainy Season","authors":"Xu-bin ZHANG, Jing-shan LI, Ya-li LUO, Xing-hua BAO, Jing-yang CHEN, Hui XIAO, Qiu-shi WEN","doi":"10.3724/j.1006-8775.2023.021","DOIUrl":"https://doi.org/10.3724/j.1006-8775.2023.021","url":null,"abstract":"","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.3724/j.1006-8775.2023.028
Shuo LIU, Jin-zhong MIN, Chen ZHANG, Shi-bo GAO
{"title":"Ideal Case Study of Adaptive Localization in Storm-scale Ensemble Kalman Filter Assimilation","authors":"Shuo LIU, Jin-zhong MIN, Chen ZHANG, Shi-bo GAO","doi":"10.3724/j.1006-8775.2023.028","DOIUrl":"https://doi.org/10.3724/j.1006-8775.2023.028","url":null,"abstract":"","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: The long-term height-resolved wind trend in China under global warming still needs to be discovered. To fill this gap, in this paper we examined the climatology and long-term (1979–2021) trends of the wintertime wind speed at the near-surface and upper atmosphere in China based on long-term radiosonde measurements. At 700, 500, and 400 hPa, much higher wind speed was found over eastern China, compared with western China. At 300, 200, and 100 hPa, maximum wind speed was observed in the latitude zone of around 25–35°N. Furthermore, westerly winds dominated most parts of China between 20°N and 50°N at altitudes from 700 hPa to 100 hPa. A stilling was revealed for the near-surface wind from 1979–2003. From 2004 onward, the near-surface wind speed reversed from decreasing to increasing. This could be largely due to the joint impact of reduced surface roughness length, aerosol optical depth (AOD), and increased sensible heat flux in the ground surface. The decrease of AOD tended to reduce aerosol radiative forcing, thereby destabilizing the planetary boundary layer (PBL). By comparison, the wintertime wind in the upper atmosphere exhibited a significant monotonic upward trend, albeit with varying magnitude for different altitudes. In the upper troposphere, the wintertime maximum wind was observed along a westerly jet stream, with a pronounced upward trend within the zone approximately bounded by latitudes of 25–50°N, particularly above 500 hPa. This accelerating wind observed in the upper troposphere and lower stratosphere could be closely associated with the large planetary-scale meridional temperature trend gradient. Besides, the direction for the wind at the near-surface and lower troposphere (925 and 850 hPa) exhibited a larger variance over the period 1979–2021, which could be associated with the strong turbulence of PBL caused by the heterogeneous land surface. For those pressure levels higher than 850 hPa, large wind directional variance was merely found to the south of 25°N. The findings from long-term radiosonde measurements in winter over China shed light on the changes in wind speed on the ground and upper atmosphere under global warming from an observational perspective.
{"title":"Contrasting Trend of Wintertime Wind Speed Between Near-surface and Upper Air in China During 1979–2021","authors":"Song-qiu WANG, Jian-ping GUO, Xiao-hui ZHENG, Jing-yan WU, Tian XIAN, Tian-meng CHEN, Zeng-liang ZANG","doi":"10.3724/j.1006-8775.2023.024","DOIUrl":"https://doi.org/10.3724/j.1006-8775.2023.024","url":null,"abstract":": The long-term height-resolved wind trend in China under global warming still needs to be discovered. To fill this gap, in this paper we examined the climatology and long-term (1979–2021) trends of the wintertime wind speed at the near-surface and upper atmosphere in China based on long-term radiosonde measurements. At 700, 500, and 400 hPa, much higher wind speed was found over eastern China, compared with western China. At 300, 200, and 100 hPa, maximum wind speed was observed in the latitude zone of around 25–35°N. Furthermore, westerly winds dominated most parts of China between 20°N and 50°N at altitudes from 700 hPa to 100 hPa. A stilling was revealed for the near-surface wind from 1979–2003. From 2004 onward, the near-surface wind speed reversed from decreasing to increasing. This could be largely due to the joint impact of reduced surface roughness length, aerosol optical depth (AOD), and increased sensible heat flux in the ground surface. The decrease of AOD tended to reduce aerosol radiative forcing, thereby destabilizing the planetary boundary layer (PBL). By comparison, the wintertime wind in the upper atmosphere exhibited a significant monotonic upward trend, albeit with varying magnitude for different altitudes. In the upper troposphere, the wintertime maximum wind was observed along a westerly jet stream, with a pronounced upward trend within the zone approximately bounded by latitudes of 25–50°N, particularly above 500 hPa. This accelerating wind observed in the upper troposphere and lower stratosphere could be closely associated with the large planetary-scale meridional temperature trend gradient. Besides, the direction for the wind at the near-surface and lower troposphere (925 and 850 hPa) exhibited a larger variance over the period 1979–2021, which could be associated with the strong turbulence of PBL caused by the heterogeneous land surface. For those pressure levels higher than 850 hPa, large wind directional variance was merely found to the south of 25°N. The findings from long-term radiosonde measurements in winter over China shed light on the changes in wind speed on the ground and upper atmosphere under global warming from an observational perspective.","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: The Lightning Imaging Sensor (LIS) and Radar Precipitation Feature (RPF) data are used to investigate the activities and properties of lightning and thunderstorms over a region including the Western Pacific, northern Indian Ocean and the South China Sea along with their adjacent lands. The lands feature significantly more frequent lightning flashes and thunderstorms than the oceans, especially the open oceans. The highest densities of lightning and thunderstorm occur over the Strait of Malacca and the southern foothills of the Himalayas. Over the ocean regions, the Bay of Bengal and the South China Sea are characterized by relatively frequent lightning and thunderstorm activities. Larger average spatiotemporal size and optical radiance of flashes can be found over the oceans; specifically, the offshore area features the most significant flash duration, and the open ocean area is characterized by the greatest flash length and optical radiance. The smallest average values of flash properties can be found over and around the Tibetan Plateau (TP). The oceanic thunderstorms tend to have a significantly larger horizontal extent than the continental thunderstorms, with the former and latter having the average area of the regions with radar reflectivity larger than 20 dBZ, generally over 7000 km 2 and commonly below 6000 km 2 , respectively. The TP thunderstorms show the smallest horizontal extent. Meanwhile, the oceanic thunderstorms exhibit greater 20 dBZ but smaller 40 dBZ top heights than the continental thunderstorms. The average flash frequency and density of the oceanic thunderstorms are typically less than 5 fl min –1 and 0.3 fl 100 km –2 min –1 , respectively; in contrast, the corresponding values of continental thunderstorms are greater. It is explored that the regions associated with strong convective thunderstorms are more likely to feature small-horizontal-extent and low-radiance flashes.
{"title":"Thunderstorm and Lightning Activities over Western Pacific, Northern Indian Ocean and South China Sea Along with Their Adjacent Lands","authors":"Jia-xin DING, Yi-jun ZHANG, Dong ZHENG, Wen YAO, Wen-juan ZHANG","doi":"10.3724/j.1006-8775.2023.026","DOIUrl":"https://doi.org/10.3724/j.1006-8775.2023.026","url":null,"abstract":": The Lightning Imaging Sensor (LIS) and Radar Precipitation Feature (RPF) data are used to investigate the activities and properties of lightning and thunderstorms over a region including the Western Pacific, northern Indian Ocean and the South China Sea along with their adjacent lands. The lands feature significantly more frequent lightning flashes and thunderstorms than the oceans, especially the open oceans. The highest densities of lightning and thunderstorm occur over the Strait of Malacca and the southern foothills of the Himalayas. Over the ocean regions, the Bay of Bengal and the South China Sea are characterized by relatively frequent lightning and thunderstorm activities. Larger average spatiotemporal size and optical radiance of flashes can be found over the oceans; specifically, the offshore area features the most significant flash duration, and the open ocean area is characterized by the greatest flash length and optical radiance. The smallest average values of flash properties can be found over and around the Tibetan Plateau (TP). The oceanic thunderstorms tend to have a significantly larger horizontal extent than the continental thunderstorms, with the former and latter having the average area of the regions with radar reflectivity larger than 20 dBZ, generally over 7000 km 2 and commonly below 6000 km 2 , respectively. The TP thunderstorms show the smallest horizontal extent. Meanwhile, the oceanic thunderstorms exhibit greater 20 dBZ but smaller 40 dBZ top heights than the continental thunderstorms. The average flash frequency and density of the oceanic thunderstorms are typically less than 5 fl min –1 and 0.3 fl 100 km –2 min –1 , respectively; in contrast, the corresponding values of continental thunderstorms are greater. It is explored that the regions associated with strong convective thunderstorms are more likely to feature small-horizontal-extent and low-radiance flashes.","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.3724/j.1006-8775.2023.023
Ming-jie ZHOU, Mao-qiu JIAN, Si GAO
: The interdecadal change in the interannual variability of the South China Sea summer monsoon (SCSSM) intensity and its mechanism are investigated in this study. The interannual variability of the low-level circulation of the SCSSM has experienced a significant interdecadal enhancement around the end of the 1980s, which may be attributed to the interdecadal changes in the evolution of the tropical Indo-Pacific sea surface temperature (SST) anomalies and their impacts on the SCSSM. From 1961 to 1989, the low-level circulation over the South China Sea is primarily affected by the SST anomalies in the tropical Indian Ocean via the mechanism of Kelvin-wave-induced Ekman divergence. While in 1990 to 2020, the impacts of the summer SST anomalies in the Maritime Continent and the equatorial central to eastern Pacific on the SCSSM are enhanced, via anomalous meridional circulation and Mastuno-Gill type Rossby wave atmospheric response, respectively. The above interdecadal changes are closely associated with the interdecadal changes in the evolution of El Niño–Southern Oscillation (ENSO) events. The interdecadal variation of the summer SST anomalies in the developing and decaying phases of ENSO events enhances the influence of the tropical Indo-Pacific SST on the SCSSM, resulting in the interdecadal change in the interannual variability of the SCSSM.
{"title":"Interdecadal Change in the Interannual Variability of South China Sea Summer Monsoon Intensity","authors":"Ming-jie ZHOU, Mao-qiu JIAN, Si GAO","doi":"10.3724/j.1006-8775.2023.023","DOIUrl":"https://doi.org/10.3724/j.1006-8775.2023.023","url":null,"abstract":": The interdecadal change in the interannual variability of the South China Sea summer monsoon (SCSSM) intensity and its mechanism are investigated in this study. The interannual variability of the low-level circulation of the SCSSM has experienced a significant interdecadal enhancement around the end of the 1980s, which may be attributed to the interdecadal changes in the evolution of the tropical Indo-Pacific sea surface temperature (SST) anomalies and their impacts on the SCSSM. From 1961 to 1989, the low-level circulation over the South China Sea is primarily affected by the SST anomalies in the tropical Indian Ocean via the mechanism of Kelvin-wave-induced Ekman divergence. While in 1990 to 2020, the impacts of the summer SST anomalies in the Maritime Continent and the equatorial central to eastern Pacific on the SCSSM are enhanced, via anomalous meridional circulation and Mastuno-Gill type Rossby wave atmospheric response, respectively. The above interdecadal changes are closely associated with the interdecadal changes in the evolution of El Niño–Southern Oscillation (ENSO) events. The interdecadal variation of the summer SST anomalies in the developing and decaying phases of ENSO events enhances the influence of the tropical Indo-Pacific SST on the SCSSM, resulting in the interdecadal change in the interannual variability of the SCSSM.","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.46267/j.1006-8775.2023.016
Xia Feng, Liu Xian-tong, Hu Sheng, Li Hui-qi, Rao Xiao-na, Lin Qing, Xiao Hui, Feng Lu, Lai Rui-ze
{"title":"Comparison of Microphysical Characteristics of Warm-sector, Frontal and Shear-line Heavy Rainfall During the Pre-summer Rainy Season in South China","authors":"Xia Feng, Liu Xian-tong, Hu Sheng, Li Hui-qi, Rao Xiao-na, Lin Qing, Xiao Hui, Feng Lu, Lai Rui-ze","doi":"10.46267/j.1006-8775.2023.016","DOIUrl":"https://doi.org/10.46267/j.1006-8775.2023.016","url":null,"abstract":"","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85621452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.46267/j.1006-8775.2023.003
Zhang Yuan-chun, Lu Rong, Sun Jian-hua, Yang Xin-lin
{"title":"Organizational Modes and Environmental Conditions of the Severe Convective Weathers Produced by the Mesoscale Convective Systems in South China","authors":"Zhang Yuan-chun, Lu Rong, Sun Jian-hua, Yang Xin-lin","doi":"10.46267/j.1006-8775.2023.003","DOIUrl":"https://doi.org/10.46267/j.1006-8775.2023.003","url":null,"abstract":"","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78371065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.46267/j.1006-8775.2023.013
Liu Qing-qing, Li Chun-hui, Gu De-jun, Zheng Bin, Lin Ai-lan, Peng Dong-dong
{"title":"Impacts of Sea Surface Temperature on the Interannual Variability of Winter Haze Days in Guangdong Province","authors":"Liu Qing-qing, Li Chun-hui, Gu De-jun, Zheng Bin, Lin Ai-lan, Peng Dong-dong","doi":"10.46267/j.1006-8775.2023.013","DOIUrl":"https://doi.org/10.46267/j.1006-8775.2023.013","url":null,"abstract":"","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88060020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.46267/j.1006-8775.2023.009
Dong Shao-rou, Yang Song, Liu Wei, Hu Ya-min, Wang Ming-sheng, Liu Yan
{"title":"Analysis of Precipitation Anomaly and a Failed Prediction During the Dragon-boat Rain Period in 2022","authors":"Dong Shao-rou, Yang Song, Liu Wei, Hu Ya-min, Wang Ming-sheng, Liu Yan","doi":"10.46267/j.1006-8775.2023.009","DOIUrl":"https://doi.org/10.46267/j.1006-8775.2023.009","url":null,"abstract":"","PeriodicalId":17432,"journal":{"name":"热带气象学报","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90305995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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