황사발생량 예측을 위한 임계마찰속도 산정 방법 개선 = Improvement of the Method of Determination of Threshold Friction Velocity for Wind-blown Dust Emission Estimation

다국어 초록 (Multilingual Abstract)

Wind-blown dust is emitted when near-surface wind speed exceeds a threshold value, which is often expressed as the threshold friction velocity. Therefore, it is important to estimate the threshold friction velocity accurately for reliable wind-blown dust emission forecast. Threshold friction velocity represents the erodibility of the surface soil and depends on surface characteristics such as land-cover, soil texture, and soil moisture content. Typical air quality models in which a wind-blown dust emission module is incorporated use horizontal grid size of tens of kilometers and each grid consists of several different land-cover categories. Thus, the representative surface roughness length is generally determined as the geometric mean of those land-cover categories for computing the threshold friction velocity. According to the assessment of this study, however, the average surface roughness length leads to too high threshold friction velocity for the entire grid and unreasonably disable the dust emission from barren land portion of the grid. By comparing with an ideal case in which the grid size is infinitesimal, we suggest that the representative surface roughness length should be determined not by average of all land-cover categories but by barren land only and the fraction of barren land should be multiplied when the dust emission amount is calculated in a large grid system. The improved algorithm was applied to modelling of surface roughness length and threshold friction velocity over the wind-blown dust emission areas for an Asian dust storm event that occurred in April 2006. The meteorological model MM5 was used to estimate the soil moisture content required to calculate the threshold friction velocity. The model-estimated surface roughness length and threshold friction velocity were reasonable. In particular, the modelled threshold friction velocity was in good agreement with a previous study that analyzed the observations statistically.

참고문헌 (Reference)

1 강광규, "동북아지역의 황사 피해 분석 및 피해저감을 위한 지역 협력방안 II" 한국환경정책평가연구원 2004

2 In, H.-J., "simulation of long-range transport of Yellow Sand observed in April 1998 in Korea" 36 : 4173-4187, 2002

3 Helgren, D.M., "Wind velocities associated with dust deflation events in the western Sahara" 26 : 1147-1151, 1987

4 Mahowald, N. M., "Understanding the 30year Barbados desert dust record" 107 : 4561-, 2002

5 Priesley, C. H. B., "Turbulent Transfer in the Lower Atmosphere" University of Chicago Press 1959

6 Jaffe, D. A., "Transport of Asian air pollution to North America. Geophys" 26 : 711-714, 1999

7 Gillette, D.A., "Threshold velocities for input of soil particles into the air by desert soils" 85 : 5621-5630, 1980

8 Levin, Z., "The effects of desert particles coated with sulfate on rain formation in the eastern Mediterranean" 35 : 1511-1523, 1511

9 Ginoux, P., "Sources and distributions of dust aerosols simulated with the GOCART model" 106 : 20255-20274, 2001

10 Park, S. H., "Simulation of entrainment and transport of dust particles within North America in April 2001 ("Red Dust Episode")" 112 : D20209-, 2007

11 Park, S. H., "Sensitivity of surface characteristics on the simulation of wind-blown dust source in North America" Atmospheric Environment in press 2009

12 Park, S. H., "Relative impact of windblown dust versus anthropogenic fugitive dust in PM2.5 on air quality in North America" 115 : D16210-, 2010

13 Kalma, J. D., "Potential wind erosion in Australia: A continental perspective" 8 : 411-428, 1988

14 Fecan, F., "Parameterization of the increase of the aeolian erosion threshold wind friction velocity due to soil moisture for arid and semi-arid areas" 17 : 149-157, 1999

15 Park, S. U., "Parameterization of dust emission for the simulation of the yellow sand (Asian dust) event observed in March 2002 in Korea" 108 (108): 4618-, 2003

16 이은희, "Parameterization of Asian dust (Hwangsa) particle-size distributions for use in dust emission models" PERGAMON-ELSEVIER SCIENCE LTD 38 (38): 2155-2162, 200405

17 홍성유, "Nonlocal boundary layer vertical diffusion in a Medium-Range Forecast Model" 124 (124): 2322-2339, 199610

18 Marticorena, B., "Modeling the atmospheric dust cycle. Part 1: Design of a soil-derived dust emission scheme" 100 : 16415-16430, 1995

19 Tegen, I., "Modeling of mineral dust in the atmosphere: Sources, transport, and optical thickness" 99 : 22897-22914, 1994

20 Zender, C. S., "Mineral Dust Entrainment and Deposition (DEAD) model: Description and 1990s dust climatology" 108 : 4416-, 2003

21 Chun, Y.-S., "Long-range transport of Yellow Sand with special emphasis on the dust rise conditions in the source regions" Seoul National University 1996

22 Park, S.-U., "Field survey of Yellow Sand source regions" 2002

23 In, H.-J., "Estimation of dust emission amount for a dust stormevent occurred in April 1998 in China" 148 : 201-221, 2003

24 Haywood, J., "Estimates of the direct and indirect radiative forcing due to tropospheric aerosols" 38 : 513-543, 2000

25 Fryberger, S. G., "Dune forms and wind regime. In "A Study of Global Sand Seas" 137-170, 1979

26 Sokolik, I. N., "Direct radiative forcing by anthropogenic airborne mineral aerosols" 381 : 681-683, 1996

27 Xiu, A., "Development of a land surface model. Part I: Application in a mesoscale meteorology model" 40 : 192-209, 2001

28 박성훈, "Development of a New Wind-Blown-Dust Emission Module Using Comparative Assessment of Existing Dust Models" Taylor & Francis 28 : 267-286, 201006

29 Taylor, P., "Comments and further analysis on the effective roughness length for use in numerical three dimensional models" 39 : 403-419, 1987

30 Gong, S. L., "Characterization of soil dust distributions in China and its transport during ACE-ASIA: 2. Model simulation and validation" 108 : 4262-, 2003

31 김현미, "Application of adjoint-based forecast sensitivities to Asian dust transport events in Korea" 195 : 335-343, 200811

32 Zhao, T. L., "An assessment of dust emission schemes in modeling east Asian dust storms" 111 : D05S90-, 2006

33 Bai, N., "About Sandstorms in China, 2000. 2001" 2001

34 Shao, Y., "A simple expression for wind erosion threshold friction velocity" 105 : 22437-22443, 2000

35 Liu, M., "A high-resolution numerical study of the Asian dust storms of April 2001" 108 : 2001

36 Westphal, D.L., "A case study of mobilization and transport of Saharan dust" 45 (45): 2145-2175, 1988

37 Zhao, T. L., "A Simulated Climatology of Asian Dust Aerosol and its Trans- Pacific Transport 1. Mean climate and validation" 19 : 88-103, 2006