QUATERNARY SCIENCES Vol. 24, No. 4

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1 QUATERNARY SCIENCES Vol. 24, No. 4 J uly, (24) (, 129),,,, -,,,,,,,,,, P , P A 1 [1 ],,, [1,2 ],,,, [3 ],,, [1,2 ], [4 6 ],, [7 ] [1 ], Xiong [8 ],, 3, 3 [9,1 ] 3 [11 13 ],3, [14 ],,,, 3 : 39 E2mail igcas. ac. cn (: , ) (: G ) ,

4 : 431 2 1,, (34 34 N, 19 32 E),7. 5m,2cm ( 1cm) S L 1 7,6kaB. P. [14 ], 1 61m, [15 ], 1. 2m,1cm 4cm 14 C 3 9 6aB. P., 3 34 7aB. P., - [14,16 ],Mastersizer 2,.

2 4 : ,, (34 34 N, E),7. 5m,2cm ( 1cm) S L 1 7,6kaB. P. [14 ], 1 61m, [15 ], 1. 2m,1cm 4cm 14 C 3 9 6aB. P., aB. P., - [14,16 ],Mastersizer 2,. 2 2 m 1 1 Fig. 1 The location of loess sampling sites 3 2 ( ),3 1 : (1) 75m 75m [13,17,18 ], 75m, [19,2 ] Pye [2 ], 75m (2) 3,3, 3,

432 2 4 2 () Fig. 2 The grain size distribution of loesses from Weinan, Shaanxi and Linshan, Beijing,,,,, (3), 3 : ( ) 1 3m, 3 6m -, 4-4.

3 () Fig. 2 The grain size distribution of loesses from Weinan, Shaanxi and Linshan, Beijing,,,,, (3), 3 : ( ) 1 3m, 3 6m -, ,, [14,21,22 ] : D = - K z 5 N 5 z + ( V g + V v ) N z = - K z 5 N 5 z + V vn z + V g N z (1) D (kgπm 2 s) z K z z N z z V g V v K z 5 N 5 z, V v N z,,, V g N z,,,, V v = (1), 3 : (1) ( ) ( ),,, (2) ( ) ( ),,, [14 ] (3) ( ) ( ),,,,, Pye Stokes [2 ], V g : V g d = g m2 d 18-1 = Am2 (2) m

4 4 : 433 g g d A = 18-1 gu,l, T = LΠgu, T DT, T N z : N z = N z - DT = N z - V g N z T = N z (1 - V g T) = N z (1 - V g LΠgu) (3) ( N z ) N z = f (lg( m) ) = f ( k), k = lg ( m),, gk gk = kf ( k) dk,n z gk : gk = kf ( k) (1 - V g T) dk = kf ( k) (1 - Am 2 T) dk = kf ( k) (1 - Ae 2 k T) dk (4) = gk kf ( k) dk - AT kf ( k) e 2 k dk = gk - B T = gk - BLΠgu (5) B (5),, -, 3 [14 ],,3, -,,,3, 3 4mΠs, 1 2mΠs,, [23,24 ],,,,,,, 3 (mπs) Fig. 3 Distribution of annual average wind velocity

5 , Π,, [1 ] 36km, 51km, 48km,8km,,,,, Π,, () LANDSAT ( 1a) ( 1b) TM543 ( 1) 1a,, ;, ( 1b),,,, [25 ], 1 1 5m [25 ],,(1 5m ) 1, ;,,,, 1a,,,,,,,,, [8 ], ( ),,,, 4. 3,,,;,,

6 4 : 435,, [3 ] 3 4km,,, 2,,,, 5 (1),,,, (2),,,,,,, ( References) 1.. :, Liu Tungsheng et al. Loess and the Environment. Beijing : Science Press, Pye K. Aeolian Dust and Dust Deposits. London : Academic Press Inc. Ltd., ,.. :, Gao Qingxian, Ren Zhenhai. Dust Storm : Revenge of Nature to Human Being. Beijing : Chemical Industry Press, ,..,199, 35(3) : An Zhisheng, Xiao Jule. A study example of the dust depositional flux of the Loess Plateau. 223 Chinese Science Bulletin, 199, 35 (3) : 22 5 An Z S, Kukla G, Porter S C et al. Late Quaternary dust flow on the Chinese Loess Plateau. Catena, 1991, 18 : Ding Zhongli, Rutter N, Han Jingtai et al. A coupled environmental system formed at about 2. 5Ma in East Asia. Palaeogeography, Palaeoclimatology, Palaeoecology, 1992, 94 : ,,. -. (D ), 1996, 26 (5) : Ding Zhongli, Ren Jianzhang, Liu Tungsheng et al. Irregular change of monsoon2desert system on a millennial scale and its mechanism. Science in China (Series D), 1996, 26(5) : Xiong Shangfa, Ding Zhongli, Liu Tungsheng. Climatic implications of loess deposits from the Beijing region. Journal of Quaternary Science, 21, 16(6) : , 21, 21(1) : 29 4 Zhang Xiaoye. Source distributions, emission, transport, deposition of Asian dust and loess accumulation. Quaternary Sciences, 21, 21(1) : ,,David Rea.., 2, 18(3) : Sun Donghuai, Lu Huayu, David Rea et al. Bimode grain2size distribution of Chinese loess and its paleoclimate implication. Sedimentologica Sinica, 2, 18(3) : Acta 11 Alfaro S C, Gaudichet A, Gomes L et al. Modeling the size distribution of a soil aerosol produced by sandblasting. Journal of Geophysical Research, 1997, 12 (D1) : Alfaro S C, Gaudichet A, Gomes L et al. Mineral aerosol production by wind erosion : Aerosol particle sizes and binding energies. Research Letters, 1998, 25 (7) : Geophysical 13 Alfaro S C, Gomes L. Modeling mineral aerosol production by wind erosion: Emission intensities and aerosol size distributions in source areas. Journal of Geophysical Research, 21, 16 (D16) : ,,. 3., 23, 23(1) : 31 4 Qin Xiaoguang, Cai Binggui, Liu Tungsheng. Characteristics of Atmospheric turbulence in the eastern Asian monsoon area during MIS 3. Quaternary Sciences, 23, 23 (1) : 31 4

7 ,,..,23, 23 (1) : 19 Liu Tungsheng, Qin Xiaoguang, Cai Binggui. A preliminart study on Holocene loess deposition in Donglingshan, Beijing. ces, 23, 23(1) : 19 Quaternary Scien2 16,.., 1997, 42(23) : Lu Huayu, An Zhisheng. The influences of pretreatment methods on grain size measurement of loess2paleosol. Chinese Science Bulletin, 1997, 42(23) : Bagnold R A. The Physics of Blown Sand and Desert Dunes. London : Methuen, Lu H, Shao Y P. A new model for dust emission by saltation bombardment. Journal of Geophysical Research, 1999, 14(D14) : Iversen J D,White B R. Saltation threshold on Earth, Mars and Venus. Sedimentology, 1982, 29 : Shao Y P,Lu H et al. A simple expression for wind erosion threshold friction velocity. Journal of Geophysical Research, 2, 15 (D17) : Slinn W G N. Dry deposition and resuspension of aerosol particles : A new look at some old problems. In : Englemann R J, Sehmel G A eds. Atmosphere - Surface Exchange of Particulate and Gaseous Pollutants (1974). Springfield, Virginia : National Technical Information Service, Twomey S. Atmospheric Aerosols, Developments in Atmospheric Science 7. Elsevier : Scientific Publishing Company, :, Hou Renzhi ed. Chinese Integration Atlas. Beijing : Sinomaps Press, :, Qian Linqing. Climate of Loess Plateau. Beijing : China Meteorology Press, :, Committee of National Atlas. National natural Atlas of P. R. C. Beijing : Sinomaps Press, THE DIFFERENCE BETWEEN D UST2TRANSPORTING WIND SYSTEMS OF BEIJING2ZHANGJIAKOU AREA AND THE LOESS PLATEAU SINCE THE L GM Qin Xiaoguang Wu Jinshui Cai Binggui Gu Zhaoyan Liu Tungsheng ( Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 129) Abstract In recent years, the impact of dust storm on Beijing area is paid more attention to. It s helpful for ascertaining the key governing areas and improving the air quality of Beijing to analyze the major dust sources of loess of the Beijing2 Zhangjiakou area by studying the loess deposition of this area. The loess is a windblown deposition, grain size distribution of which contains the information of atmospheric dynamics during dust transportation. In this paper, the dust transporting wind system of the Beijing2Zhangjiakou area is compared with that of the loess plateau by studying the grain size distribution of loess and analyzing the wind2eroded traces on the LANDSAT TM remotely sensed images. It was found that dust of Beijing2Zhangjiakou area mainly came along the Sonid Youqi2Erenhot direction in north of Yinshan mountain and the atmospheric dynamic strength in the dust source area of loess of Beijing2Zhangjiakou area was stronger than that of the Loess Plateau. Key words dust2transporting wind system, aerodynamic force, grain size distribution, wind2eroded traces

The atmospheric turbulence in the East Asia monsoon area since 60kaBP: A preliminary. study of the multimodal grain size distribution of Chinese loess

The atmospheric turbulence in the East Asia monsoon area since 60kaBP: A preliminary study of the multimodal grain size distribution of Chinese loess Xiaoguang Qin, Binggui Cai, Tungsheng Liu Abstract: