Spatiotemporal Variation of Snow Cover Frequency in the Qilian Mountains (Northwestern China) during 2000–2020 and Associated Circulation Mechanisms
Linking snow cover frequency (SCF) and atmospheric circulation is vital for comprehension of hemispheric-scale change mechanisms and for accurate forecasting. This study combined MODIS imagery with meteorological observations to investigate the variation of annual SCFs in the Qilian Mountains. Resul...
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ftdoajarticles:oai:doaj.org/article:9fa3c98e9de34467aa537d5e55bc028d 2023-05-15T15:00:52+02:00 Spatiotemporal Variation of Snow Cover Frequency in the Qilian Mountains (Northwestern China) during 2000–2020 and Associated Circulation Mechanisms Wentao Du Shichang Kang Libing Qian Youyan Jiang Wenxuan Sun Jizu Chen Zhilong Xu Weijun Sun Xiang Qin Xian Chai 2022-06-01T00:00:00Z https://doi.org/10.3390/rs14122823 https://doaj.org/article/9fa3c98e9de34467aa537d5e55bc028d EN eng MDPI AG https://www.mdpi.com/2072-4292/14/12/2823 https://doaj.org/toc/2072-4292 doi:10.3390/rs14122823 2072-4292 https://doaj.org/article/9fa3c98e9de34467aa537d5e55bc028d Remote Sensing, Vol 14, Iss 2823, p 2823 (2022) snow cover frequency spatiotemporal variation topographic influence climate driving circulation mechanism Science Q article 2022 ftdoajarticles https://doi.org/10.3390/rs14122823 2022-12-31T03:14:14Z Linking snow cover frequency (SCF) and atmospheric circulation is vital for comprehension of hemispheric-scale change mechanisms and for accurate forecasting. This study combined MODIS imagery with meteorological observations to investigate the variation of annual SCFs in the Qilian Mountains. Results indicated that more than 80% of annual SCF is distributed at high elevations and mostly on northern slopes, and that SCF is greater in the west than in the east. Abrupt change in the increase in annual SCF was not detected; however, significant (0.05 confidence level) variation with quasi-3-year and quasi-5-year periods indicated potential connection with monsoons. Topographically, SCF increased at high elevations and decreased in valleys. Moreover, SCF increased significantly with a rise in slope below 23° and then decreased between 23° and 45°, and it decreased with a change in aspect from 70° to 200° and then increased from 200° to 310°. Annual SCF variation in the Qilian Mountains is dominated by precipitation rather than by temperature. In the years with high SCFs, southeasterly winds associated with an anticyclone over southeastern China and southwesterly winds associated with the cyclone over the Iranian Plateau brought warm moisture across northwestern China, favoring snowfall in the Qilian Mountains. Meanwhile, cold moisture outbreaks from the Arctic into the mid-latitudes are conducive to maintaining snow cover. However, in the years with low SCFs, the cold air might be difficultly transporting out of the Arctic region due to the strengthening polar vortex. Moreover, the water vapor was less than that of the mean state and divergence over the Qilian Mountains, which difficultly conduced snowfall over the Qilian Mountains. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic Remote Sensing 14 12 2823 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
snow cover frequency spatiotemporal variation topographic influence climate driving circulation mechanism Science Q |
spellingShingle |
snow cover frequency spatiotemporal variation topographic influence climate driving circulation mechanism Science Q Wentao Du Shichang Kang Libing Qian Youyan Jiang Wenxuan Sun Jizu Chen Zhilong Xu Weijun Sun Xiang Qin Xian Chai Spatiotemporal Variation of Snow Cover Frequency in the Qilian Mountains (Northwestern China) during 2000–2020 and Associated Circulation Mechanisms |
topic_facet |
snow cover frequency spatiotemporal variation topographic influence climate driving circulation mechanism Science Q |
description |
Linking snow cover frequency (SCF) and atmospheric circulation is vital for comprehension of hemispheric-scale change mechanisms and for accurate forecasting. This study combined MODIS imagery with meteorological observations to investigate the variation of annual SCFs in the Qilian Mountains. Results indicated that more than 80% of annual SCF is distributed at high elevations and mostly on northern slopes, and that SCF is greater in the west than in the east. Abrupt change in the increase in annual SCF was not detected; however, significant (0.05 confidence level) variation with quasi-3-year and quasi-5-year periods indicated potential connection with monsoons. Topographically, SCF increased at high elevations and decreased in valleys. Moreover, SCF increased significantly with a rise in slope below 23° and then decreased between 23° and 45°, and it decreased with a change in aspect from 70° to 200° and then increased from 200° to 310°. Annual SCF variation in the Qilian Mountains is dominated by precipitation rather than by temperature. In the years with high SCFs, southeasterly winds associated with an anticyclone over southeastern China and southwesterly winds associated with the cyclone over the Iranian Plateau brought warm moisture across northwestern China, favoring snowfall in the Qilian Mountains. Meanwhile, cold moisture outbreaks from the Arctic into the mid-latitudes are conducive to maintaining snow cover. However, in the years with low SCFs, the cold air might be difficultly transporting out of the Arctic region due to the strengthening polar vortex. Moreover, the water vapor was less than that of the mean state and divergence over the Qilian Mountains, which difficultly conduced snowfall over the Qilian Mountains. |
format |
Article in Journal/Newspaper |
author |
Wentao Du Shichang Kang Libing Qian Youyan Jiang Wenxuan Sun Jizu Chen Zhilong Xu Weijun Sun Xiang Qin Xian Chai |
author_facet |
Wentao Du Shichang Kang Libing Qian Youyan Jiang Wenxuan Sun Jizu Chen Zhilong Xu Weijun Sun Xiang Qin Xian Chai |
author_sort |
Wentao Du |
title |
Spatiotemporal Variation of Snow Cover Frequency in the Qilian Mountains (Northwestern China) during 2000–2020 and Associated Circulation Mechanisms |
title_short |
Spatiotemporal Variation of Snow Cover Frequency in the Qilian Mountains (Northwestern China) during 2000–2020 and Associated Circulation Mechanisms |
title_full |
Spatiotemporal Variation of Snow Cover Frequency in the Qilian Mountains (Northwestern China) during 2000–2020 and Associated Circulation Mechanisms |
title_fullStr |
Spatiotemporal Variation of Snow Cover Frequency in the Qilian Mountains (Northwestern China) during 2000–2020 and Associated Circulation Mechanisms |
title_full_unstemmed |
Spatiotemporal Variation of Snow Cover Frequency in the Qilian Mountains (Northwestern China) during 2000–2020 and Associated Circulation Mechanisms |
title_sort |
spatiotemporal variation of snow cover frequency in the qilian mountains (northwestern china) during 2000–2020 and associated circulation mechanisms |
publisher |
MDPI AG |
publishDate |
2022 |
url |
https://doi.org/10.3390/rs14122823 https://doaj.org/article/9fa3c98e9de34467aa537d5e55bc028d |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Remote Sensing, Vol 14, Iss 2823, p 2823 (2022) |
op_relation |
https://www.mdpi.com/2072-4292/14/12/2823 https://doaj.org/toc/2072-4292 doi:10.3390/rs14122823 2072-4292 https://doaj.org/article/9fa3c98e9de34467aa537d5e55bc028d |
op_doi |
https://doi.org/10.3390/rs14122823 |
container_title |
Remote Sensing |
container_volume |
14 |
container_issue |
12 |
container_start_page |
2823 |
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1766332920050483200 |