용평 알파인 경기장에서 겨울철 바람의 일변화 및 난류 특성분석
An Analysis of the Wintertime Diurnal Wind Variation and Turbulent Characteristics over Yongpyong Alpine Slope
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참고문헌
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초록
A 3D sonic anemometer has been installed at Yongpyong alpine slope since Oct. 23th 2014 to observe the slope winds and to analyze turbulent characteristics with the change in surface cover (grass and snow) and the synoptic wind strength. Eddy covariance method has been applied to calculate the turbulent quantity after coordinate transformation of a planar-fit rotation. We have carefully selected 3 good episodes in the winter season (23 October 2014 to 28 February 2015) for each category (9 days in total), such as grass and snow covers in case of weak synoptic wind condition, and grass cover of strong synoptic wind. The diurnal variations of the slope winds were well developed like the upslope wind in the daytime and downslope wind in the nighttime for both surface covers (grass and snow) in the weak synoptic forcing, when accordingly both heat and momentum fluxes significantly increased in the daytime and decreased in the nighttime. Meanwhile, diurnal variation of heat flux was not present on the snow cover probably in associated with significant fraction of sunlight reflection due to high albedo especially during the daytime in comparison to those on the grass cover. In the strong synoptic regime, the most dominant feature at Yongpyong, only the southeasterly downslope winds were steadily generated irrespective of day and night with significant increases in momentum flux and turbulent kinetic energy as well, which could suggest that local circulations are suppressed by the synoptic scale forcing. In spite of only one season analysis applied to the limited domain, this kind of an observation-based study will provide the basis for understanding of the local wind circulation in the complex mountain domain such as Gangwon in Korea.
Abstract
A 3D sonic anemometer has been installed at Yongpyong alpine slope since Oct. 23th 2014 to observe the slope winds and to analyze turbulent characteristics with the change in surface cover (grass and snow) and the synoptic wind strength. Eddy covariance method has been applied to calculate the turbulent quantity after coordinate transformation of a planar-fit rotation. We have carefully selected 3 good episodes in the winter season (23 October 2014 to 28 February 2015) for each category (9 days in total), such as grass and snow covers in case of weak synoptic wind condition, and grass cover of strong synoptic wind. The diurnal variations of the slope winds were well developed like the upslope wind in the daytime and downslope wind in the nighttime for both surface covers (grass and snow) in the weak synoptic forcing, when accordingly both heat and momentum fluxes significantly increased in the daytime and decreased in the nighttime. Meanwhile, diurnal variation of heat flux was not present on the snow cover probably in associated with significant fraction of sunlight reflection due to high albedo especially during the daytime in comparison to those on the grass cover. In the strong synoptic regime, the most dominant feature at Yongpyong, only the southeasterly downslope winds were steadily generated irrespective of day and night with significant increases in momentum flux and turbulent kinetic energy as well, which could suggest that local circulations are suppressed by the synoptic scale forcing. In spite of only one season analysis applied to the limited domain, this kind of an observation-based study will provide the basis for understanding of the local wind circulation in the complex mountain domain such as Gangwon in Korea.
참고문헌 (22)
- Carrera, M. L., "Observation study of wind channeling within the St. Lawrence River Valley", J. Appl. Meteor. Climatol, 48, pp.2341~2361 (2009)
- J. Cuxart, "Deep Radiation Fog in a Wide Closed Valley: Study by Numerical Modeling and Remote Sensing", Pure and Applied Geophysics, 169(5-6), pp.911~926 (2012), Springer Nature[DOI]
- Cuxart, J., "Study of mesobeta basin flows by remote sensing", Bound.-Layer Meteor, 143, pp.143~158 (2011)[DOI]
- 은승희, "한반도 중부지역에서 약한 강수에 미치는 도시화 효과", 대기, 21(3), pp.229~241 (2011), 한국기상학회
- Gustavsson, T., "Development of temperature patterns during clear nights", J. Appl. Meteor, 37, pp.559~571 (1998)
- Haiden, T., "Katabatic flow mechanisms on a low-angle slope", J. Appl. Meteor, 44, pp.113~126 (2005)
- 한선호, "산 경사면의 기울기 변화에 따른 바람장의 민감도에 관한 WRF 수치모의 연구", 대기, 17(4), pp.349~364 (2007), 한국기상학회
- Horst, T. W., "Nocturnal drainage flow on simple slopes", Bound.-Layer Meteor, 34, pp.263~286 (1986)
- Kim, B. -G., "An analysis of heavy snowfalls and cold wave and development of its forecast method in Yeongdong", National Institute of Meteorological Science, pp.35~43 (2014)
- Lee, X., "Handbook of micrometeorology: A Guide for surface Flux Measurement and Analysis", pp.250~ (2004), Klewer Academic Publishers
- Lindkvist, L., "Spatial and temporal variability of nocturnal summer frost in elevated complex terrain", Agric. Forest Meteor, 87, pp.139~153 (1997)
- Lindkvist, L., "A frost assessment method for mountainous areas", Agric. Forest Meteor, 102, pp.51~67 (2000)
- Mahrt, L., "Variation of surface air temperature in complex terrain", J. Appl. Meteor. Climatol, 45, pp.1481~1493 (2006)
- Monti, P., "Observations of flow and turbulence in the nocturnal boundary layer over a slope", J. Atmos. Sci, 59, pp.2513~2534 (2002)
- Oliver, H. R., "Studies of the energy budget of sloping terrain", Int. J. Climatol, 12, pp.55~68 (1992)
- Papadopoulos, K. H., "The structure of katabatic flows down a simple slope", Quart. J. Roy. Meteor. Soc, 123, pp.1581~1601 (1997)
- Sun, J., "Heat balance in the nocturnal boundary layer during CASES-99", J. Appl. Meteor, 42, pp.1649~1666 (2003)
- Wilczak, J. M., "Sonic anemometer tilt correction algorithms", Bound.-Layer Meteor, 99, pp.127~150 (2001)
- Whiteman, C. D., "Mountain Meteorology: Fundamentals and applications", pp.376~ (2000), Oxford University Press
- Whiteman, C. D., "The relationship between overlying synoptic-scale flows and winds within a valley", J. Appl. Meteor, 32, pp.1669~1682 (1993)
- Whiteman, C. D., "Downslope flows on a lowangle slope and their interactions with valley inversions", I. Observations. J. Appl. Meteor. Climatol, 47, pp.2023~2038 (2008)
- Zoumakis, N. M., "A simple scheme for daytime estimates of surface energy budget in complex terrain", Fresen. Environ. Bull, 15, pp.923~927 (2006)