Diurnal Variations of Summer Precipitation over the Qilian Mountains in Northwest China
- 5 Downloads
Based on the high-density hourly rain-gauge data from 265 stations over the Qilian Mountains in Northwest China, climatic mean diurnal variations of summer rainfall over different topographies of this area are investigated. Influences of the gauge elevations on the diurnal variation of rainfall are also revealed. Distinct regional features of diurnal variations in rainfall are observed over the Qilian Mountains. Rainfall over the Qinghai Lake areas shows a single nocturnal peak. A dominant, late-afternoon peak of rainfall occurs over the mountain tops. Over the northeastern and southeastern slopes, a dominant diurnal peak appears in the late afternoon, and an evident second peak is found in the early morning, respectively. The strengths of the early-morning peaks in the rainfall frequency are closely related to the rainfall events with different durations over the two slopes. The early-morning peak is dominant across plains with low elevations. From the mountain tops to the plains, the diurnal peaks of rainfall gradually vary from the dominant late-afternoon peak to the dominant early-morning peak with the enhanced early-morning peak in concurrent with the decreasing gauge elevation over the northeastern and southeastern slopes. Further examination indicates that the rainfall at higher elevations over the northeastern and southeastern slopes occurs more readily in the afternoon, compared to the lower elevations. This phenomenon corresponds to the result that the proportion of the rainfall frequency occurring during the early-morning period decreases with increasing elevations over the two slopes.
Key wordsthe Qilian Mountains diurnal cycle topographic effects spatial distribution duration
Unable to display preview. Download preview PDF.
The authors wish to thank the Editor and the anonymous reviewers for their constructive comments and valuable suggestions.
- Ding, X. R., 2003: Water increasing effect of mountains and its value of water resources. J. Mountain Res., 21: 681–685, doi: 10.3969/j.issn.1008-2786.2003.06.007. (in Chinese)Google Scholar
- Jia, W. X., Y. S. Zhang, and Z. X. Li, 2014: Spatial and temporal change of rainfall extremes in Qilian Mountains and Hexi Corridor in recent 50 years. Scientia Geogra. Sinica, 34: 1002–1009, doi: 10.11821/xb201205006. (in Chinese)Google Scholar
- Li, Y. Y., Q. Zhang, X. Xu, et al., 2010: Relationship between precipitation and terrain over the Qilian Mountains and their ambient areas. J. Glaciol. Geocryol., 32: 52–61. (in Chinese)Google Scholar
- Liang, H., J. M. Liu, and Y. Chen, 2010: Characteristics and cause of diurnal variation of precipitable water vapor derived from ground-based GPS in Qilian Mountains in summer. Plateau Meteor., 29: 726–736. (in Chinese)Google Scholar
- Liu, X. M., M. J. Zhang, S. J. Wang, et al., 2016: Diurnal variation of summer precipitation and its influencing factors over the Qilian Mountains during 2008–2014. Acta Geogra. Sinica, 71: 754–767, doi: 10.11821/dlxb201605005. (in Chinese)Google Scholar
- Singh, P., and K. Nakamura, 2009: Diurnal variation in summer precipitation over the central Tibetan Plateau. J. Geophys. Res. Atmos., 114, D20107, doi: 10.1029/2009JD011788.Google Scholar
- Yin, X. Z., Q. Zhang, Q. Y. Xu, et al., 2009: Characteristics of climate change in Qilian Mountains region in recent 50 years. Plateau Meteor., 28: 85–90. (in Chinese)Google Scholar
- Yu, R. C., and J. Li, 2016: Regional characteristics of diurnal peak phases of precipitation over contiguous China. Acta Meteor. Sinica, 74: 18–30, doi: 10.11676/qxxb2016.011. (in Chinese)Google Scholar
- Yu, R. C., Y. P. Xu, T. J. Zhou, et al., 2007: Relation between rainfall duration and diurnal variation in the warm season precipitation over central eastern China. Geophys. Res. Lett., 34, L13703, doi: 10.1029/2007GL030315.Google Scholar
- Zhang, J., and D. L. Li, 2004: Analysis on distribution characteristics of rainfall over the Qilian Mountain and Heihe Valley. Plateau Meteor., 23: 81–88, doi: 10.3321/j.issn:1000-0534. 2004.01.012. (in Chinese)Google Scholar
- Zhang, L., Q. Zhang, J. Y. Feng, et al., 2014: A study of atmospheric water cycle over the Qilian Mountains (I): Variation of annual water vapor transport. J. Glaciol. Geocryol., 36: 1079–1091, doi: 10.7522/j.issn.1000-0240.2014.0130. (in Chinese)Google Scholar