Meteorological Drought Changes and Related Circulation Characteristics in Yulin City of the Northern Shaanxi from 1961 to 2015
This study explored the spatio-temporal patterns of meteorological drought change and the mechanisms of drought occurrence in Yulin City of the northern Shaanxi by using Standardized Precipitation Index (SPI), Empirical Orthogonal Function (EOF) analysis and composite analysis based on the meteorolo...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-11-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/11/11/1196 |
| _version_ | 1797548847862382592 |
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| author | Yixing Yin Lijuan Zhang Xiaojun Wang Wucheng Xu Wenjun Yu Ye Zhu |
| author_facet | Yixing Yin Lijuan Zhang Xiaojun Wang Wucheng Xu Wenjun Yu Ye Zhu |
| author_sort | Yixing Yin |
| collection | DOAJ |
| description | This study explored the spatio-temporal patterns of meteorological drought change and the mechanisms of drought occurrence in Yulin City of the northern Shaanxi by using Standardized Precipitation Index (SPI), Empirical Orthogonal Function (EOF) analysis and composite analysis based on the meteorological observation data and NCEP/NCAR reanalysis data from 1961 to 2015. The main findings of the research are as follows: (1) In the annual and seasonal drought series, there is a non-significant trend toward drought in summer, while there are non-significant trends toward wetness for the other series. Overall, the frequency of drought is low in the southeast and high in the west and the north of the study area. (2) EOF1 is characterized by a uniform pattern in the whole region, i.e., there is a feature of consistent drought or flood in Yulin City. EOF2, EOF3 and EOF4 mainly indicate opposite characteristics of the changes of floods and droughts in the eastern/western parts and the southeast/other parts in the study area. (3) In the summer of the typical drought (flood) years, the study area is controlled by the northwest airflow behind the trough (zonal airflow at the bottom of low-pressure trough), and the meridional circulation (zonal circulation) is distributed in the mid-latitudes, which is conducive to the intrusion of cold air into the south (north) of China. The cold and warm air intersection area is to the south (to the north). The water vapor flux is weak (strong) and the water vapor divergence (convergence) prohibits (enhances) the precipitation process in the study area. |
| first_indexed | 2024-03-10T15:05:37Z |
| format | Article |
| id | doaj.art-f412c8474f56445d92e244c8a549665c |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T15:05:37Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-f412c8474f56445d92e244c8a549665c2023-11-20T19:49:50ZengMDPI AGAtmosphere2073-44332020-11-011111119610.3390/atmos11111196Meteorological Drought Changes and Related Circulation Characteristics in Yulin City of the Northern Shaanxi from 1961 to 2015Yixing Yin0Lijuan Zhang1Xiaojun Wang2Wucheng Xu3Wenjun Yu4Ye Zhu5School of Hydrology and Water Resources, Nanjing University of Information Science and Technology, Nanjing 210044, ChinaTongren Meteorological Bureau of Guizhou Province, Tongren 554300, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, ChinaSchool of Land and Resources, China West Normal University, Nanchong 637002, ChinaSchool of Hydrology and Water Resources, Nanjing University of Information Science and Technology, Nanjing 210044, ChinaSchool of Hydrology and Water Resources, Nanjing University of Information Science and Technology, Nanjing 210044, ChinaThis study explored the spatio-temporal patterns of meteorological drought change and the mechanisms of drought occurrence in Yulin City of the northern Shaanxi by using Standardized Precipitation Index (SPI), Empirical Orthogonal Function (EOF) analysis and composite analysis based on the meteorological observation data and NCEP/NCAR reanalysis data from 1961 to 2015. The main findings of the research are as follows: (1) In the annual and seasonal drought series, there is a non-significant trend toward drought in summer, while there are non-significant trends toward wetness for the other series. Overall, the frequency of drought is low in the southeast and high in the west and the north of the study area. (2) EOF1 is characterized by a uniform pattern in the whole region, i.e., there is a feature of consistent drought or flood in Yulin City. EOF2, EOF3 and EOF4 mainly indicate opposite characteristics of the changes of floods and droughts in the eastern/western parts and the southeast/other parts in the study area. (3) In the summer of the typical drought (flood) years, the study area is controlled by the northwest airflow behind the trough (zonal airflow at the bottom of low-pressure trough), and the meridional circulation (zonal circulation) is distributed in the mid-latitudes, which is conducive to the intrusion of cold air into the south (north) of China. The cold and warm air intersection area is to the south (to the north). The water vapor flux is weak (strong) and the water vapor divergence (convergence) prohibits (enhances) the precipitation process in the study area.https://www.mdpi.com/2073-4433/11/11/1196meteorological droughtspatio-temporal patterncirculation characteristicsnorthern Shaanxistandardized precipitation index |
| spellingShingle | Yixing Yin Lijuan Zhang Xiaojun Wang Wucheng Xu Wenjun Yu Ye Zhu Meteorological Drought Changes and Related Circulation Characteristics in Yulin City of the Northern Shaanxi from 1961 to 2015 Atmosphere meteorological drought spatio-temporal pattern circulation characteristics northern Shaanxi standardized precipitation index |
| title | Meteorological Drought Changes and Related Circulation Characteristics in Yulin City of the Northern Shaanxi from 1961 to 2015 |
| title_full | Meteorological Drought Changes and Related Circulation Characteristics in Yulin City of the Northern Shaanxi from 1961 to 2015 |
| title_fullStr | Meteorological Drought Changes and Related Circulation Characteristics in Yulin City of the Northern Shaanxi from 1961 to 2015 |
| title_full_unstemmed | Meteorological Drought Changes and Related Circulation Characteristics in Yulin City of the Northern Shaanxi from 1961 to 2015 |
| title_short | Meteorological Drought Changes and Related Circulation Characteristics in Yulin City of the Northern Shaanxi from 1961 to 2015 |
| title_sort | meteorological drought changes and related circulation characteristics in yulin city of the northern shaanxi from 1961 to 2015 |
| topic | meteorological drought spatio-temporal pattern circulation characteristics northern Shaanxi standardized precipitation index |
| url | https://www.mdpi.com/2073-4433/11/11/1196 |
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